PRODUCTS THEREOF

TECHNICAL FIELD

The present disclosure generally relates to a method to synthesize hydroxyl and carboxyl functional oligomers from recycled polymers, and more particularly to a method to synthesize hydroxyl and carboxyl functional oligomers from recycled polyethylene terephthalate (r-PET) through controlled depolymerization.

BACKGROUND

Thermoplastic polyesters are processable to yield corresponding controlled depolymerized products. Specifically, polyethylene terephthalate (PET) and polybutylene terephthalate (PBT) are processable to yield corresponding controlled depolymerized value-added products. Polyethylene terephthalate (PET) has polymerized units of the monomer, ethylene terephthalate, with repeating unit of Cio¾0 ₄ . PET is not recycled as the cost of recycling is high and the unrecycled PET leads to landfills. This has negative impacts on the environment, therefore there is a need for a method to recycle PET in a cost-effective way. Generally, it is broken into its constituent monomers through excess glycolysis or hydrolysis and in the presence of catalysts. It is then re-used.

Some of the existing technologies use an average temperature of 195°C for about 5.5 hours. Some technologies use glycolysis with an average temperature of 210°C for about 160 min. then main taining at 260°C for 30 minutes. Some processes additionally require energy to condensate methylol groups for polymer formation. In another process, glycolysis is carried out an average temperature of 180°C for about 240 min. and then cooled and reheated to 200°C for 360 min. In yet another process, average temperature of 230°C and a minimum time of 8 hours is reported. Some existing technologies use an average temperature of 180°C for about 300 min. and then maintained at 200°C for 240 min. In another process an average temperature of 220°C is used for about 180 min. The existing technologies disclose a wide range of operations, for example, lower temperatures but longer times. In the existing technologies, reaction mass increases due to addition of polyacids and excess glycol. The processes require higher energy for removal of condensate due to esterification reactions. In some processes, methylol groups have to condensate and as a result, water of condensation has to be removed thus making them more energy intensive.

Further, the existing methods use catalysts, exotic or otherwise, and/or reagents to recycle PET. Further, the energy requirements for manufacturing by these methods are high due to multiple steps involved. There is a need for an improved method of recycling r-PET that involves fewer steps and is economical.

SUMMARY:

In one aspect, a process to synthesize hydroxyl or carboxyl functional oligomers from recycled PET (r-PET) through controlled depolymerization is disclosed. The r-PET chips are cleaned by a plurality of wash cycles to obtain clean r-PET chips. The clean r-PET chips are free of impurities and have a size in a range of up to 2 mm. The cleaned r-PET chips are dried. The r-PET chips are subjected to a controlled depolymerization in presence of glycerine to obtain hydroxyl functional oligomers with very low amounts mono-functional moieties. The controlled depolymerization is carried out at a temperature in a range of 230 °C to 280 °C for a period of 30- 180 minutes. Glycerine and r-PET chips are present in a weight ratio in a range of 1:2.3 to 1:30. The hydroxyl functional oligomers are further reacted with anhydrides or polyfunctional carboxylic acids to yield carboxyl functional oligomers directly.

In another aspect, a process to synthesize hydroxyl or carboxyl functional oligomers from r-PET through controlled depolymerization is disclosed. The r-PET chips are cleaned by a plurality of wash cycles to obtain clean r-PET chips free of impurities. The r-PET chips have a size in a range of up to 2 mm. The cleaned r-PET chips are dried and subjected to a controlled depolymerization in presence of glycerine and a triglyceride to obtain hydroxyl functional oligomers. The controlled depolymerization is carried out at a temperature in a range of 230 °C to 280 °C for a period of 30- 180 minutes. Glycerine and r-PET chips are present in a weight ratio in a range of 1:23 to 1:30. The weight ratio of the triglyceride to glycerine is 1 :0 to 1 : 1.79. The hydroxyl functional oligomers are further reacted with anhydrides or polyfunctional carboxylic acids to yield carboxyl functional oligomers directly. The reaction is done at 160 °C to 220 °C in 10-180 minutes. In yet another aspect, products obtained from a process to synthesize functional oligomers from r- PET through controlled depolymerization are disclosed. The r-PET chips are cleaned by a plurality of wash cycles to obtain clean r-PET chips free of impurities. The r-PET chips have a size in a range of up to 2 mm. The cleaned r-PET chips are dried and subjected to a controlled depolymerization in presence of glycerine and a triglyceride to obtain oligomers. Glycerine and r- PET chips are present in a weight ratio in a range of 1:23 to 1:30. The weight ratio of the triglyceride to glycerine is 1:0 to 1:1.79. The hydroxyl functional oligomers are further reacted with anhydrides or polyfunctional carboxylic acids to yield carboxyl functional oligomers directly. The reaction is done at 160 °C to 220 °C in 10-180 minutes.

The hydroxyl or carboxyl functional oligomers are reacted with isocyanates, blocked isocyanates, melamines or epoxies to obtain powder coatings, melamine coatings, casting systems, polyols for foams, etc. or used as compatibilizers or wetting and dispersing additives for Polyesters and other plastics.

BRIEF DESCRIPTION OF THE DRAWINGS:

The disclosed system will be described and explained with additional specificity and detail with the accompanying figures in which

Figure 1 is a flow chart illustrating a method for recycling of r-PET, in accordance with an embodiment of the present disclosure; and

Figure 2 is a flow chart illustrating a method for recycling of r-PET, in accordance with another embodiment of the present disclosure.

Further, persons skilled in the art to which this disclosure belongs will appreciate that elements in the figures are illustrated for simplicity. Furthermore, the figures may show only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the figures with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. DETAILED DESCRIPTION:

Those skilled in the art will be aware that the present disclosure is subject to variations and modifications other than those specifically described. It is to be understood that the present disclosure includes all such variations and modifications. The disclosure also includes all such components of the composition, features of composition, referred to or indicated in this specification, individually or collectively and any and all combinations of any or more of such components or features.

For convenience, before further description of the present disclosure, certain terms employed in the specification, and examples are collected here. These definitions should be read in the light of the remainder of the disclosure and understood as by a person of skill in the art. The terms used herein have their meanings recognized and known to those of skill in the art, however, for convenience and completeness, particular terms and their meanings are set forth below.

The articles “a”, “an” and “the” are used to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article.

The terms “comprise” and “comprising” are used in the inclusive, open sense, meaning that additional elements may be included. It is not intended to be construed as “consists of only”.

Throughout this specification, unless the context requires otherwise the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated element or step or group of element or steps but not the exclusion of any other element or step or group of element or steps.

The term “including” is used to mean “including but not limited to”. “Including” and “including but not limited to” are used interchangeably.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the disclosure, the preferred methods, and materials are now described. All publications mentioned herein are incorporated herein by reference.

The present disclosure is not to be limited in scope by the specific embodiments described herein, which are intended for the purposes of exemplification only. Functionally equivalent products and processes are clearly within the scope of the disclosure, as described herein.

The disclosed method uses bio-sourced or bio-source derivable materials in the process. The dis closed method is a simple process for recycling single use thermoplastic into multiple applications. The proposed method presents significant energy savings while manufacturing and during appli cation stage as glycolysis, even with catalysts, requires high energy input, whereas the disclosed process is a partial glycolysis, therefore requires less energy.

The recycled PET finds applications in industrial coatings, coil coatings, rigid foams for insulation, sound dampening, in artificial wood (thermoplastic and thermoset) and as additives.

Commercial PET has an average molecular weight of 15000 to 25000. Glycerine has two primary hydroxyl groups (methylol) and one secondary hydroxyl group. The depolymerization of PET takes places through transesterification by the primary groups (methylol), leaving the secondary hydroxyl groups unreacted, specifically in the absence of a catalyst. Further, commercial PET is end capped, as the uncapped ends lead to processing issues and does not have reactive groups at the end. Glycerine is a triol and hence for each interaction of the primary methylol groups of glycerine with PET, chain scission takes place on the PET and the glycerine attaches itself to one of the fragments while the secondary hydroxyl group remains unreacted during the process, i.e. during transesterification, an ester is formed with each interaction of the primary methylol group of the glycerine and a hydroxyl group is exposed at the scission point on the PET. Through the above reaction, low molecular weight moieties are obtained with hydroxyl functionality. The implications of this are that the average molecular weight of the final hydroxyl or carboxyl functional oligomers may vary according to the starting molecular weight of r-PET but the hydroxyl value of the final hydroxyl or carboxyl functional oligomers may be calculated based on the amount of glycerine and/or the hydroxyl content of the triglyceride. Generally due to ease of processing conditions, excess amounts of glycols are used. Glycerine is a polyol, mainly used due to the presence of primary methylol groups along with a secondary hydroxyl group. In some embodiments alternate synthetic materials, such as pentaerythritol, trimethylol propane (TMP) may be used.

As illustrated in Figure 1, the present disclosure relates to a process 100 to synthesize hydroxyl and carboxyl functional oligomers from r-PET through controlled depolymerization. The process includes step 102 where r-PET chips are cleaned using a plurality of wash cycles to obtain clean r-PET chips. The r-PET chips have a size in a range of up to 2 mm. The cleaned r-PET chips are dried. Step 102 is followed by step 104 where the r-PET chips are subjected to a controlled depol ymerization in presence of glycerine to obtain hydroxyl functional oligomers. The controlled de polymerization is carried out at a temperature in a range of 230 °C to 280 °C for a period of 30- 180 minutes. Glycerine and r-PET chips are present in a weight ratio in a range of 1 :23 to 1 : 30. At step 106, The hydroxyl functional oligomers are further reacted with anhydrides or polyfunctional carboxylic acids to yield carboxyl functional oligomers directly. The reaction is done at 160 °C to 220 °C in 10-180 minutes the hydroxyl functional oligomers are reacted with anhydrides or poly- functional carboxylic acids to yield carboxyl functional oligomers directly.

Other methylol containing compounds such as trimethylol propane, pentaerythritol, and sucrose may also be used instead of glycerine. However, methylol containing diols such as neopentyl gly col will yield oligomers with very low reactivity and/or high monol content and therefore are not preferred.

Further, as shown in Figure 2, the present disclosure relates to a process 200 to synthesize hydroxyl and carboxyl functional oligomers from r-PET through controlled depolymerization. The process includes step 202 where r-PET chips are cleaned using a plurality of wash cycles to obtain clean r-PET chips. The r-PET chips have a size in a range of up to 2 mm. The cleaned r-PET chips are dried. Step 202 is followed by step 204 where the r-PET chips are subjected to a controlled depolymerization in presence of glycerine and a triglyceride to obtain hydroxyl functional oligomers. The controlled depolymerization is carried out at a temperature in a range of 230 °C to 280 °C for a period of 30-180 minutes. Glycerine and r-PET chips are present in a weight ratio in a range of 1:2.3 to 1:30. The weight ratio of the triglyceride to glycerine is 1:0 to 1:1.79. At step 206, the hydroxyl functional oligomers are further reacted with anhydrides or polyfunctional carboxylic acids to yield carboxyl functional oligomers directly. The reaction is done at 160 °C to 220 °C in 10-180 minutes. The hydroxyl functional oligomers and carboxyl functional oligomers so obtained can be used in reactive systems or as additives such as compatibilizers, flow enhancers/processing aids, wetting and dispersing agents.

In an embodiment, of the many triglycerides available, castor oil and flaxseed oil are selected.

In yet another embodiment, anhydrides are selected, either bio sourced or chemically obtained such as succinic anhydride, maleic anhydride, or trimilletic anhydride. The anhydrides provide carboxyl functionality, and the final hydroxyl or carboxyl functional oligomers may find application in powder coatings. The unreacted carboxyl groups may provide ionic sites for electrodeposition during spray and further acts as an adhesion promoter. Preferably, anhydrides which do not form any by-products of condensation are used. Further, using anhydrides, the additional step of removal of condensate is avoided, thus minimizing the energy requirement of the process.

In yet another embodiment, the polyfunctional carboxylic acids may be selected from a range of dicarboxylic acids, and tricarboxylic acids.

In another embodiment, the r-PET chips are cleaned in a pH neutral soap solution under agitation at room temperature for about 30 minutes. This is followed by rinsing with demineralized water, air drying and drying the washed r-PET chips in an oven at 110 °C- 130 °C for about 2-3 hours. This is further followed by rinsing the dried r-PET chips in solution of isopropanol (IP A) and toluene. IPA and Toluene are present in a weight ratio of 1 : 1. This is subsequently followed by drying the washed r-PET chips in an oven at 110 °C- 130 °C for about 2-3 hours. The plurality of wash cycles ensure that the r-PET chips are cleaned thoroughly.

In another embodiment, the controlled depolymerization is carried out at a temperature in a range of 230 °C to 280 °C and for a period of 90-210 minutes. The optimum temperature is found to be 240-260 °C. r-PET chips do not dissolve easily and tend to agglomerate if addition time is decreased. On the other hand, if addition time is increased, glycerine gets consumed entirely before completion of addition thereby giving undigested streams.

Melt flow index (MFI) is a flow rate measurement. Lower values of MFI (at the same temperature and load) indicate higher flow rates which indicates lower molecular weights moieties. In the present disclosure, a constant value of MFI is achieved indicating no changes in the average mo lecular weight. Type of mixer, speed of agitator, and design of mixing vessel will affect the time, and thus MFI values. MFI measurements show that reaction time greater than 90 minutes has little or no effect on the MFI of the final product.

It is known in the art that PET is de-polymerized using various glycols to its constituent monomers using excess of glycols along with catalysts. Glycerine, being a poor solvent for PET and there- formed oligomers, hinders its reactivity because the composition change is dependent on reactions taking place simultaneously in liquid and solid phases. r-PET is completely soluble in glycerine at temperatures above 230 °C and the reaction proceeds smoothly at 260 °C.

The molecular weight of commercial PET is in the range of 15 to 25 kg/mol and by using glycerine and glycerine with castor oil (both of which have secondary hydroxyl groups redundant to the reaction), the process ensures that the molecular weight of the final hydroxyl and carboxyl functional oligomer results in hydroxyl or carboxyl functional oligomers with an average functionality >2 with very low amounts mono-functional moieties. Functionality of a monomer defines the number of polymerizable groups and affects the formation and the degree of crosslinking of polymers.

In another embodiment, the glycerine and r-PET chips are in a ratio in a range of 1 :2.3 to 1:30. In yet another embodiment, the ratio of the vegetable oil to glycerine is 1:0 to 1:1.79. The use of monoglycerides with flax seed, coconut oil and other vegetable oils yields usable ethylene terephthalate-based oligomers with functionality of <2 which act as compatibilizers for PET with other polymers such as polyethylene, polypropylene, and polyolefins whereby properties of these recycled plastics are improved. Triglyceride may be used along with the glycerine wherein the ratio of oil to glycerine is maintained at a minimum 1 mole oil: 1 mole glycerine thereby leaving at least one methylol group for reacting with the r-PET. Triglycerides when used in the above process yields usable ethylene terephthalate-based oligomers with unsaturation which can be further dissolved in Styrene to be used in lieu of unsaturated polyester hydroxyl or carboxyl functional oligomers systems.

The average molecular weight is an indication of the functionality. The hydroxyl value is con trolled only by the glycol content. The average molecular weight and the functionality are im portant in product design. For example, materials with high molecular weight and high function ality are not viable and become unusable in most applications. The theoretical monomer, as the methylol groups glycolyse the r-PET, thus formed, without monomeric glycol, is with 2 tereph- thalic molecules with one glycerine molecule and two ethylene glycol molecules with hydroxyl equivalent weight 156 and molecular weight 468. The average molecular weights and hydroxyl values have been chosen empirically to balance hardener consumption and flowability in curing.

In yet another embodiment, the process is carried out in absence of a catalyst. Subjecting the r- PET chips to a controlled depolymerization yields a completely dissolved product stream comprising hydroxyl functional oligomers.

In yet another embodiment, antioxidants may be used during depolymerization to control the final color of the hydroxyl or carboxyl functional oligomers.

In a further embodiment, the hydroxyl or carboxyl functional oligomers are reacted with isocyanates, blocked isocyanates, melamines or epoxies to obtain powder coatings, melamine coatings, casting systems, or polyols for foams.

EXAMPLES:

Having described the basic aspects of the present disclosure, the following non-limiting examples illustrate specific embodiments thereof. Those skilled in the art will appreciate that many modifications may be made in the disclosure without changing the essence of the disclosure.

Example 1

PET chips were procured from two different recycling sources. The chips were further ground using a kitchen grinder and sieved in to up to 2mm particles and stored under Nitrogen. The ground chipped were first cleaned in a soap solution of distilled water under agitation at room temperature for 30 minutes. The ground chips were dried in an oven at 110 deg. C for 2 hours. A sample of lOg of dried chips was added to 30g distilled water and the pH was checked to be 7. They were again rinsed in a 1 : 1 by weight solution of isopropanol (IPA) and toluene. This was air dried overnight, and dried in a vacuum oven at 130 deg. C for 2 hours. Moisture analysis on a Karl Fischer titrator showed moisture in sample to be less than 0.02%. Solids analysis showed non-volatile matter (NVM) to be greater than 99.99%, viz. Volatiles were less than 0.01%. The above procedure was standardized for all trials using the r-PET chips. Further, all materials were dehydrated under vacuum at 125 °C for 3 hours to give materials with <0.03%moisture.

Example 2

Initial trials were conducted by varying times of stirring. MFI of the samples were recorded, and it was found that the MFI remained constant even though the time of cooking was increased. Nitrogen purging was maintained throughout the reaction.

One litre capacity flanged round bottom borosilicate flask was flushed with 9.99% pure nitrogen while room temperature and atmospheric pressure was maintained. 65 grams of dehydrated glycerine was added to the reactor under nitrogen purge. The reactor was heated to 230°C to 280°C 600 grams of the cleaned and dried r-PET chips were added to the reactor. The addition was finished in under 45 minutes maintaining at a temperature of 230°C to 280°C. The reactants were stirred for a further 30-180 minutes at 230°C to 280°C. The quantity of reactants used are presented in Table 1 and the molecular weights of the r-PET chips and hydroxyl functional oligomers so obtained are presented in Table 2. The molecular weight of the commercially available PET is 15000- 25000, and the theoretical average molecular weight of the hydroxyl functional oligomers is in the range of 890-911. For this experiment, acid value was found to be 3.4 mgKOH/g sample. Acid value is directly linked with side reactions of moisture. The hydroxyl value was 179.9 mgKOH/g sample, and the MFI was 5.1 g/lOmin. @ 165°C.

Table 1

Table 2

Example 3

One litre capacity flanged round bottom borosibcate flask was flushed with 9.99% pure nitrogen while room temperature and atmospheric pressure was maintained. 67.59 grams of dehydrated glycerine was added to the reactor under nitrogen purge. The reactor was heated to 230°C to 280°C. 811.5 grams of the cleaned and dried r-PET chips were added to the reactor. The addition was finished in under 45 minutes maintaining at a temperature of 230°C to 280°C. The reactants were stirred for a further 30-180 minutes at 230°C to 280°C. The quantity of reactants used are presented in Table 3 and the molecular weights of the r-PET chips and hydroxyl functional oligomers so obtained are presented in Table 4. The molecular weight of the commercially available PET is 15000- 25000, and the theoretical average molecular weight of the hydroxyl functional oligomers is in the range of 1114-1146. For this experiment, acid value was found to be 4.4 mgKOH/g sample. Acid value is directly linked with side reactions of moisture. The hydroxyl value was 142.5 mgKOH/g sample, and the MFI was 5.1 g/lOmin. @ 187°C.

Table 3

Table 4

Example 4

One litre capacity flanged round bottom borosilicate flask was flushed with 9.99% pure nitrogen while room temperature and atmospheric pressure was maintained. 79.74 grams of dehydrated glycerine and 56.96 grams of dehydrated castor oil was added to the reactor under nitrogen purge. The reactor was heated to 230°C to 280°C. 717.66 grams of the cleaned and dried r-PET chips were added to the reactor. The addition was finished in under 45 minutes maintaining at a temperature of 230°C to 280°C. The reactants were stirred for a further 30-180 minutes at 230°C to 280°C. The quantity of reactants used are presented in Table 5 and the molecular weights of the r-PET chips and hydroxyl functional oligomers so obtained are presented are presented in Table 6. The molecular weight of the commercially available PET is 15000- 25000, and the theoretical average molecular weight of the hydroxyl functional oligomers is in the range of 1114-1146. For this experiment, acid value was found to be 3.7 mgKOH/g sample. Acid value is directly linked with side reactions of moisture. The hydroxyl value was 185.6 mgKOH/g sample, and the MFI was 5.4 g/lOmin. @ 165°C.

Table 5

Table 6 Example 5

One litre capacity flanged round bottom borosilicate flask was flushed with 9.99% pure nitrogen while room temperature and atmospheric pressure was maintained. 55.60 grams of dehydrated glycerine and 111.21 grams of dehydrated castor oil was added to the reactor under nitrogen purge. The reactor was heated to 230°C to 280°C. 667.25 grams of the cleaned and dried r-PET chips were added to the reactor. The addition was finished in under 45 minutes maintaining at a temperature of 230°C to 280°C. The reactants were stirred for a further 30-180 minutes at 230°C to 280°C. The quantity of reactants used are presented in Table 7 and the molecular weights of the r-PET chips and hydroxyl functional oligomers so obtained are presented are presented in Table 8. The molecular weight of the commercially available PET is 15000- 25000, and the theoretical average molecular weight of the oligomers is in the range of 1114-1146. For this experiment, acid value was found to be 3.2 mgKOH/g sample. Acid value is directly linked with side reactions of moisture. The hydroxyl value was 140.7 mgKOH/g sample, and the MFI was 4.78 g/lOmin. @ 160°C.

Table 7

Table 8

Example 6

One litre capacity flanged round bottom borosilicate flask was flushed with 9.99% pure nitrogen while room temperature and atmospheric pressure was maintained. 23.35 grams of dehydrated glycerine and 114.20 grams of dehydrated castor oil was added to the reactor under nitrogen purge. The reactor was heated to 230°C to 280°C. 697.86 grams of the cleaned and dried r-PET chips were added to the reactor. The addition was finished in under 45 minutes maintaining at a temperature of 230°C to 280°C. The reactants were stirred for a further 30-180 minutes at 230°C to 280°C. The quantity of reactants used are presented in Table 9 and the molecular weights of the r-PET chips and hydroxyl functional oligomers so obtained are presented are presented in Table 10. The molecular weight of the commercially available PET is 15000- 25000, and the theoretical average molecular weight of the hydroxyl functional oligomers is in the range of 1955-2045. For this experiment, acid value was found to be 2.6 mgKOH/g sample. Acid value is directly linked with side reactions of moisture. The hydroxyl value was 72.8 mgKOH/g sample, and the MFI was 4.5 g/lOmin. @ 190°C.

Table 9 Table 10 Example 7

One litre capacity flanged round bottom borosilicate flask was flushed with 9.99% pure nitrogen while room temperature and atmospheric pressure was maintained. 27.26 grams of dehydrated glycerine and 133.33 grams of dehydrated castor oil was added to the reactor under nitrogen purge. The reactor was heated to 230°C to 280°C. 666.67 grams of the cleaned and dried r-PET chips were added to the reactor. The addition was finished in under 45 minutes maintaining at a temperature of 230°C to 280°C. The reactants were stirred for a further 30-180 minutes at 230°C to 280°C. The quantity of reactants used are presented in Table 11 and the molecular weights of the r-PET chips and hydroxyl functional oligomers so obtained are presented are presented in Table 12. The molecular weight of the commercially available PET is 15000- 25000, and the theoretical average molecular weight of the hydroxyl functional oligomers is in the range of 1692-1756. For this experiment, acid value was found to be 3.5 mgKOH/g sample. Acid value is directly linked with side reactions of moisture. The hydroxyl value was 90.2 mgKOH/g sample, and the MFI was 4.8 g/lOmin. @ 170°C.

Table 11

Table 12

Example 8

One litre capacity flanged round bottom borosilicate flask was flushed with 9.99% pure nitrogen while room temperature and atmospheric pressure was maintained. 25.15 grams of dehydrated glycerine and 123.02 grams of dehydrated castor oil was added to the reactor under nitrogen purge. The reactor was heated to 230°C to 280°C. 683.47 grams of the cleaned and dried r-PET chips were added to the reactor. The addition was finished in under 45 minutes maintaining at a temperature of 230°C to 280°C. The reactants were stirred for a further 30-180 minutes at 230°C to 280°C. The quantity of reactants used are presented in Table 13 and the molecular weights of the r-PET chips and hydroxyl functional oligomers so obtained are presented are presented in Table 14. The molecular weight of the commercially available PET is 15000- 25000, and the theoretical average molecular weight of the hydroxyl functional oligomers is in the range of 1825-1902. For this experiment, acid value was found to be 3.9 mgKOH/g sample. Acid value is directly linked with side reactions of moisture. The hydroxyl value was 66.3 mgKOH/g sample, and the MFI was 2.92 g/lOmin. @ 182°C.

Table 13

Table 14

Example 9

One litre capacity flanged round bottom borosilicate flask was flushed with 9.99% pure nitrogen while room temperature and atmospheric pressure was maintained. 23.48 grams of dehydrated glycerine and 114.83 grams of dehydrated castor oil was added to the reactor under nitrogen purge. The reactor was heated to 230°C to 280°C. 574.13 grams of the cleaned and dried r-PET chips were added to the reactor. The addition was finished in under 45 minutes maintaining at a temperature of 230°C to 280°C. The reactants were stirred for a further 30-180 minutes at 230°C to 280°C. 110.97 grams of succinic anhydride was added to the reactants at a temperature of 180°C. The reactants were further stirred further at 160°C to 220°C for 10-180 minutes to obtain target acid value. The resultant product was then spread on a tray. The quantity of reactants used are presented in Table 15 and the molecular weights are presented in Table 16. The molecular weight of the commercially available PET is 15000- 25000, and the theoretical average molecular weight of the hydroxyl functional oligomers is in the range of 1825-1902. For this experiment, acid value was found to be 78.5 mgKOH/g sample. Acid value is directly linked with side reactions of moisture. The MFI was 2.99 g/lOmin. @ 158°C. Table 15

Table 16

Example 10

One litre capacity flanged round bottom borosilicate flask was flushed with 9.99% pure nitrogen while room temperature and atmospheric pressure was maintained. 20.08 grams of dehydrated glycerine and 98.21 grams of dehydrated castor oil was added to the reactor under nitrogen purge. The reactor was heated to 230°C to 280°C. 600.18 grams of the cleaned and dried r-PET chips were added to the reactor. The addition was finished in under 45 minutes maintaining at a temperature of 230°C to 280°C. The reactants were stirred for a further 30-180 minutes at 230°C to 280°C. 111.91 grams of succinic anhydride was added to the reactants at a temperature of 180 °C. The reactants were further stirred at 160 °C to 220 °C for 10- 180 minutes. The resultant product was then spread on a tray. The quantity of reactants used are presented in Table 17 and the molecular weights are presented in Table 18. The molecular weight of the commercially available PET is 15000- 25000, and the theoretical average molecular weight of the hydroxyl functional oligomers is in the range of 2214-2315. For this experiment, acid value was found to be 70.3 mgKOH/g sample. Acid value is directly linked with side reactions of moisture. The MFI was 3.22 g/lOmin. @ 175°C.

Table 17

Table 18

Example 11

46.65 grams of Triglycidyl isocyanurate, 2.23 grams of Polyether modified polysiloxane which acts as a levelling agent, 0.22 grams of silicone defoamer and 6.70 grams of Trisnonyl phenyl phopshite (TNPP) was added to in a 250ml flask and mixed for 30 minutes till uniform using a magnetic stirrer. The product was then spread on tray and cooled and subsequently crushed to a particle size of up to 2 mm. 399.82 grams of the resultant product of example 10 was also crushed to a particle size of up to 2 mm and mixed with the above product. The mixture was extruded in a compounding co-rotating extruder and ground into fine particles and sieved through 325 mesh. The extruded particles were spray applied on mechanically cleaned MS panel and cured at 180°C for 20 minutes to obtain films that passed 100 MEK double rubs on testing. The quantity of reactants used are presented in Table 19. Table 19

Example 12 55.85 grams of Standard liquid epoxy (Bisphenol A diglycidyl ether), 2.00 grams of polyether modified polysiloxane which acts as a levelling agent, 0.14 grams of silicone defoamer, 5.72 grams of IRGANOX® 1010, which acts as an anti-oxidant and 2.86 grams of silicone flow agent was added to in a 250ml flask at a temperature of 110 °C and mixed for 30 minutes till uniform using a magnetic stirrer. The product was then spread on tray and cooled and subsequently crushed to a particle size of up to 2 mm. 230.24 grams of the resultant product of example 9 was also crushed to a particle size of up to 2 mm and mixed with the above product. The mixture was extruded in a compounding co-rotating extruder and ground into fine particles and sieved through 325 mesh. The extruded particles were spray applied on mechanically cleaned MS panel and cured at 180°C for 20 45 minutes to obtain films that passed 100 MEK double rubs on testing. The quantity of reactants used are presented in Table 20.

Table 20

Example 13

41.17 grams Triglycidyl isocyanurate, 0.29 grams of polyether modified polysiloxane which acts as a levelling agent, 0.02 grams of silicone defoamer and 0.82 grams of IRGANOX® 1010 which acts as an anti-oxidant was added to in a 250ml flask at a temperature of 110 °C and mixed for 30 minutes till uniform using a magnetic stirrer. The product was then spread on tray and cooled and subsequently crushed to a particle size of up to 2 mm. 264.32 grams of the resultant product of example 7 was also crushed to a particle size of up to 2 mm and mixed with the above product. The mixture was extruded in a compounding co-rotating extruder and ground into fine particles and sieved through 325 mesh. The extruded particles were spray applied on mechanically cleaned MS panel and cured at 185°C for 45- 20 minutes to obtain films that passed 100 MEK double rubs on testing. The quantity of reactants used are presented in Table 21.

Table 21

Example 14

One litre capacity flanged round bottom borosilicate flask was flushed with 9.99% pure nitrogen while room temperature and atmospheric pressure was maintained. 265.25 grams of dehydrated caprolactam and 3.53 grams of dibutyl tin dilaurate was added to the reactor at 80°C to 120°C. 441.54 grams of Hexamethylene diisocyanate (HDI) Isocyanurate was added to the reactor at that a temperature below 85°C and was maintained at this temperature. The isocyanate value is checked with IN Dibutylamine (DBA) every 30min. till the isocyanate value is zero. After the isocyanate value reaches zero, the product was then spread on a tray and cooled. The quantity of reactants used are presented in Table 22. Table 22

Example 15

One litre capacity flanged round bottom borosilicate flask was flushed with 9.99% pure nitrogen while room temperature and atmospheric pressure was maintained. 307.86 grams of dehydrated caprolactam and 1.32 grams of dibutyl tin dilaurate was added to the reactor at 80°C to 120°C. 349.76 grams of DESMODUR® 2460 (Mixture of Diphenylmethane diisocyanate isomers) was added to the reactor at that temperature and was maintained at this temperature. The isocyanate value is checked with IN DBA every 30 minutes till the isocyanate value is zero. After the isocyanate value reaches zero, the product was then spread on a tray and cooled. The quantity of reactants used are presented in Table 23.

Table 23 Example 16

One litre capacity flanged round bottom borosilicate flask was flushed with 9.99% pure nitrogen while room temperature and atmospheric pressure was maintained. 305.82 grams of dehydrated caprolactam and 1.33 grams of dibutyl tin dilaurate was added to the reactor at 80°C to 120°C. 358.06 grams of polymeric Methylene diphenyl diisocyanate (MDI) (with an Isocyanate value of 30.5) was added to the reactor at that temperature and was maintained at this temperature. The isocyanate value is checked with IN DBA every 30 minutes till the isocyanate value is zero. After the isocyanate value reaches zero, the product was then spread on a tray and cooled. The quantity of reactants used are presented in Table 24.

Table 24

Example 17

144.51 grams of the resultant product of example 14 was pre-heated to 90°C in a reactor. 2.89 grams of dibutyl tin dilaurate, 2.89 grams of polyether modified polysiloxane, 1.45 grams of silicone defoamer were added to the reactor. The product was spread on tray and left overnight and subsequently crushed to a particle size of up to 2 mm. This product is mixed with 144.51 grams of the product of example 2 which has been crushed to a particle size of up to 2 mm. The mixture was extruded in a compounding co-rotating extruder and ground into fine particles and sieved through 325 mesh. The extruded particles were spray applied on mechanically cleaned MS panel and cured at 210° C for 6 minutes to obtain films that passed 100 MEK double rubs on testing. The quantity of reactants used are presented in Table 25. Table 25

Example 18 72.12 grams of the resultant product of example 16 was pre-heated to 90°C in a reactor. 1.97 grams of polyether modified polysiloxane, 0.14 grams of silicone defoamer, 5.64 grams of IRGANOX® 1010 and 8.45 grams of tributyl phosphate were added to the reactor. The product was spread on tray and left overnight and subsequently crushed to a particle size of up to 2 mm. This product is mixed with 209.64 grams of the product of example 6 which has been crushed to a particle size of up to 2 mm. The mixture was extruded in a compounding co-rotating extruder and ground into fine particles and sieved through 325 mesh. The extruded particles were spray applied on mechanically cleaned MS panel and cured at 210° C for 6 minutes to obtain films that passed 100 MEK double rubs on testing. The quantity of reactants used are presented in Table 26. Table 26 Example 19

73.19 grams of the resultant product of example 15 was pre-heated to 90°C in a reactor. 1.97 grams of polyether modified polysiloxane, 0.14 grams of silicone defoamer, 5.64 grams of IRGANOX® 1010 and 8.45 grams of tributyl phosphate were added to the reactor. The product was spread on tray and left overnight and subsequently crushed to a particle size of up to 2 mm. This product is mixed with 208.57 grams of the product of example 6 which has been crushed to a particle size of up to 2 mm. The mixture was extruded in a compounding co-rotating extruder and ground into fine particles and sieved through 325 mesh. The extruded particles were spray applied on mechanically cleaned MS panel and cured at 210°C for 6 minutes to obtain films that passed 100 MEK double rubs on testing. The quantity of reactants used are presented in Table 27.

Table 27 Example 20

84.83 grams of the resultant product of example 15 was pre-heated to 90°C in a reactor. 2.01 grams of polyether modified polysiloxane, 0.14 grams of silicone defoamer, 5.73 grams of IRGANOX® 1010 and 2.87 grams of tributyl phosphate were added to the reactor. The product was spread on tray and left overnight and subsequently crushed to a particle size of up to 2 mm. This product is mixed with 201.84 grams of the product of example 6 which has been crushed to a particle size of up to 2 mm. The mixture was extruded in a compounding co-rotating extruder and ground into fine particles and sieved through 325 mesh. The extruded particles were spray applied on mechanically cleaned MS panel and cured at 210°C for 6 minutes to obtain films that passed 100 MEK double rubs on testing. The quantity of reactants used are presented in Table 28.

Table 28

Example 21

84.45 grams of the resultant product of example 15 was pre-heated to 90°C in a reactor. 2.02 grams of polyether modified polysiloxane, 0.14 grams of silicone defoamer, 5.77 grams of IRGANOX® 1010 and 2.89 grams of tributyl phosphate were added to the reactor. The product was spread on tray and left overnight and subsequently crushed to a particle size of up to 2 mm. This product is mixed with 204.08 grams of the product of example 7 which has been crushed to a particle size of up to 2 mm. The mixture was extruded in a compounding co-rotating extruder and ground into fine particles and sieved through 325 mesh. The extruded particles were spray applied on mechanically cleaned MS panel and cured at 210°C for 6 minutes to obtain films that passed 100 MEK double rubs on testing. The quantity of reactants used are presented in Table 28.

Table 28

Example 22

81.80 grams of the resultant product of example 16 was pre-heated to 90 °C in a reactor. 1.98 grams of polyether modified polysiloxane, 0.14 grams of silicone defoamer, 5.67 grams of IRGANOX® 1010 and 7.09 grams of tributyl phosphate were added to the reactor. The product was spread on tray and left overnight and subsequently crushed to a particle size of up to 2 mm. This product is mixed with 201.67 grams of the product of example 7 which has been crushed to a particle size of up to 2 mm. The mixture was extruded in a compounding co-rotating extruder and ground into fine particles and sieved through 325 mesh. The extruded particles were spray applied on mechanically cleaned MS panel and cured at 210°C for 6 minutes to obtain films that passed 100 MEK double rubs on testing. The quantity of reactants used are presented in Table 29.

Table 29 Example 23

93.35 grams of the resultant product of example 14 was pre-heated to 90 °C in a reactor. 1.46 grams of poly ether modified polysiloxane, 0.15 grams of silicone defoamer, and 4.37 grams of tris nonyl phenyl phosphite (TNPP) were added to the reactor. The product was spread on tray and left overnight and subsequently crushed to a particle size of up to 2 mm. This product is mixed with 197.80 grams of the product of example 7 which has been crushed to a particle size of up to 2 mm. The mixture was extruded in a compounding co-rotating extruder and ground into fine particles and sieved through 325 mesh. The extruded particles were spray applied on mechanically cleaned MS panel and cured at 210°C for 6 minutes to obtain films that passed 100 MEK double rubs on testing. The quantity of reactants used are presented in Table 30.

Table 30

Example 24

76.12 grams of the resultant product of example 15 was pre-heated to 90 °C in a reactor. 1.47 grams of poly ether modified polysiloxane, 0.15 grams of silicone defoamer, and 4.40 grams of tris nonyl phenyl phosphite (TNPP) were added to the reactor. The product was spread on tray and left overnight and subsequently crushed to a particle size of up to 2 mm. This product is mixed with 217.19 grams of the product of example 8 which has been crushed to a particle size of up to 2 mm. The mixture was extruded in a compounding co-rotating extruder and ground into fine particles and sieved through 325 mesh. The extruded particles were spray applied on mechanically cleaned MS panel and cured at 210°C for 6 minutes to obtain films that passed 100 MEK double rubs on testing. The quantity of reactants used are presented in Table 31.

Table 31

Example 25

88.54 grams of the resultant product of example 16 was pre-heated to 90 °C in a reactor. 1.98 grams of polyether modified polysiloxane, 0.14 grams of silicone defoamer, 5.66 grams of IRGANOX® 1010 and 5.66 grams of tributyl phosphate were added to the reactor. The product was spread on tray and left overnight and subsequently crushed to a particle size of up to 2 mm. This product is mixed with 194.53 grams of the product of example 8 which has been crushed to a particle size of up to 2 mm. The mixture was extruded in a compounding co-rotating extruder and ground into fine particles and sieved through 325 mesh. The extruded particles were spray applied on mechanically cleaned MS panel and cured at 210°C for 6 minutes to obtain films that passed 100 MEK double rubs on testing. The quantity of reactants used are presented in Table 32.

Table 32

Example 26 318.15 grams of the resultant product of example 14 was pre-heated to 90 °C in a reactor. 7.12 grams of poly ether modified polysiloxane, 0.51 grams of silicone defoamer, 20.34 grams of IRGANOX® 1010 and 20.34 grams of tributyl phosphate were added to the reactor. The product was spread on tray and left overnight and subsequently crushed to a particle size of up to 2 mm. This product is mixed with 699.00 grams of the product of example 8 which has been crushed to a particle size of up to 2 mm. The mixture was extruded in a compounding co-rotating extruder and ground into fine particles and sieved through 325 mesh. The extruded particles were spray applied on mechanically cleaned MS panel and cured at 210°C for 6 minutes to obtain films that passed 100 MEK double rubs on testing. The quantity of reactants used are presented in Table 33. Table 33 Example 27

One litre capacity flanged round bottom borosilicate flask was flushed with 9.99% pure nitrogen while room temperature and atmospheric pressure was maintained. 64.13 grams of dehydrated glycerine and 306.01 grams of linseed oil was added to the reactor. The reactor was heated to 250 °C to 230°C to 280°C and maintained for 5 to 60 minutes. 370.14 grams of the cleaned and dried r-PET chips were added to the reactor. The reactants were stirred for 60 to 180 minutes at 230°C to 280°C. The resultant product was then spread on a tray at 160 °C to 180 °C. The quantity of reactants used are presented in Table 34.

Table 34

Example 28

85.15 grams of a mixture of r-PET and r-LDPE were ground together into up to 2 mm particles and the particles were cleaned. 5.11 grams of product of example 27 were added to the particles. The mixture was extruded up to 5 times through a twin screw extruder and pelletized to obtain homogenous extrudates.

Example 29

83.03 grams of a mixture of r-PET and r-LDPE were ground together into up to 2 mm particles and the particles were cleaned. 12.46 grams of product of example 27 were added to the particles. The mixture was extruded up to 5 times through a twin screw extruder and pelletized to obtain homogenous extrudates.

Example 30

154.33 grams of a mixture of r-PET and r-LDPE were ground together into up to 2 mm particles and the particles were cleaned. 14.47 grams of product of example 27 were added to the particles. The mixture was extruded up to 5 times through a twin screw extruder and pelletized to obtain homogenous extrudates.

Example 31 79.37 grams of a mixture of r-PET and r-LDPE were ground together into up to 2 mm particles and the particles were cleaned. 11.90 grams of product of example 27 were added to the particles. The mixture was extruded up to 5 times through a twin screw extruder and pelletized to obtain homogenous extrudates. Example 32

135.59 grams of a mixture of r-PET and r-LDPE were ground together into up to 2 mm particles and the particles were cleaned. 12.71 grams of product of example 27 were added to the particles. The mixture was extruded up to 5 times through a twin screw extruder and pelletized to obtain homogenous extrudates.

Example 33

91.01 grams of a mixture of r-PET and r-LDPE were ground together into up to 2 mm particles and the particles were cleaned. 13.65 grams of product of example 27 were added to the particles. The mixture was extruded up to 5 times through a twin screw extruder and pelletized to obtain homogenous extrudates.

Example 34

164.37 grams of a mixture of r-PET and r-LDPE were ground together into up to 2 mm particles and the particles were cleaned. 15.41 grams of product of example 27 were added to the particles. The mixture was extruded up to 5 times through a twin screw extruder and pelletized to obtain homogenous extrudates.

Example 35

56.01 grams of a mixture of r-PET and r-LDPE were ground together into up to 2 mm particles and the particles were cleaned. 7.28 grams of product of example 27 were added to the particles. The mixture was extruded up to 5 times through a twin screw extruder and pelletized to obtain homogenous extrudates.