Technical Filed The present invention pertains to polyurethane, in particularly, pertains to a polyurethane with improved abrasion resistance, the method for preparing the same and use thereof.

Background

Polyurethane (in particularly polyurethane elastomer), which possesses good tear strength, good flex fatigue resistance and relative low density, is a kind of material having extensive use, such as footwear, carpet, roller, coating and soft parts used in automotive. Especially in the industry of footwear making, shoe-soles made from polyurethane (especially from polyurethane elastomers) possess a lot of advantages such as light weight, slip resistance, good rebound, high strength, oil resistance, etc,. Isocyanate compounds with an active hydrogen-containing compound (for example, polyester polyol or polyether polyol), in the presence of a catalyst and/or blowing agent. The polyester-based polyurethanes possess good mechanical properties, however, the low temperature properties, hydrolysis resistance properties and anti-mold properties of the polyester-based polyurethanes are bad, furthermore the processing technology of the polyester-based polyurethanes are relatively complicated. On the other hand, the polyether-based polyurethanes possess good hydrolysis resistance properties, good low temperature properties, however, the mechanical properties, especially the abrasion resistance, of the polyether-based polyurethanes are relatively bad. In addition, preparing polyurethane by use of non-aqueous inert physical blowing agent, such as fluorine- containing blowing agent, might pollute the environment; preparing polyurethane by use of water as blowing agent, will bring negative influence to the mechanical properties of the polyurethane, especially the abrasion resistance.

In the prior art, a couple of trials have been applied to improve the mechanical properties of polyurethanes (especially polyurethane elastomers). For example, CN10922 I OC disclosed a method for preparing a polyurethane elastomer in the presence of liquid polybutadiene to improve the mechanical properties of polyurethane elastomer. However, in accordance with the method, the amount of the liquid polybutadiene was 0.1-10 weight parts based on 100 weight parts of the polyols, wherein in the polybutadiene the amount of the 1,2-butene was less than 50%, the amount of the 2,3 (cis)-butene was higher than the amount of the 2,3-(trans) butane. The abrasion resistance of the polyurethane elastomer obtained according to this method was 81-270 mg (tested according to IS04649).

In addition, US4242468 disclosed a method for preparing polyurethanes by adding a monohydroxylated polybutadiene as a nonmigratory plasticizer. US5079270 disclosed a method for preparing polyurethanes by adding a liquid polybutadiene as an internal mold release agent

The present invention pertains to a polyurethane with improved abrasion resistance and the method for preparing the same. The polyurethane obtained in this invention possesses good abrasion resistance and surface appearance.

Content of Invention

The objective of this invention is to provide a polyurethane. According to an example of this invention, the polyurethane comprising the reaction product of reaction components of:

A) one or more isocyanates, wherein said isocyanate comprises diisocyanate and/or polyisocyanate;

B) one or more polyols;

C) one or more catalysts; and

D) 0.05-5 wt.% polybutadiene, based on 100 % by weight of A), B), C) and D); said polybutadiene comprises 1 ,2-butene structure unit, 2,3-(cis) butene structure unit and 2,3 -(trans) butene structure unit, wherein, based on 100 % by weight of polybutadiene, the amount of thel ,2-butene structure unit is less than 30 wt.%, the amount of the 2,3- (trans) butene structure unit is more than the amount of the 2,3 -(cis) butene structure unit, the amount of the 2,3-(trans) butene structure unit is 40-50 wt.%.

Preferably, the amount of the 2,3-(trans) butene structure unit is 43-50 wt.%, based on 100 wt.% of the polybutadiene.

Preferably, the molecular weight of the polybutadiene is 1000-20000.

Preferably, the density of the polyurethane is 100-1200 kg/m ³ .

Preferably, the abrasion resistance of the polyurethane is less than or equal to 215 mg, tested according to IS04649. Another objective of this invention is to provide a method preparing polyurethane, comprising the step of reacting components of A), B), C) and D):

A) one or more isocyanates, wherein said isocyanate comprises diisocyanate and/or polyisocyanate; B) one or more polyols;

C) one or more catalysts; and

D) 0.05-5 wt.% polybutadiene, based on 100 % by weight of A), B), C) and D); said polybutadiene comprises 1 ,2-butene structure unit, 2,3-(cis) butene structure unit and 2,3 -(trans) butene structure unit, wherein, based on 100 % by weight of polybutadiene, the amount of thel ,2-butene structure unit is less than 30 wt.%, the amount of the 2,3-

(trans) butene structure unit is more than the amount of the 2,3 -(cis) butene structure unit, the amount of the 2,3 -(trans) butene structure unit is 40-50 wt.%.

Preferably, the 2,3-(trans) butene content is 43-50 wt.%, based on 100 wt.% of the butene content.

Preferably, the molecular weight of the polybutadiene is 1000-20000. Preferably, the polybutadiene is 0.1 -4 wt.%, based on 100 wt.% of A, B, C and D.

Another objective of this invention is to provide a use of the polyurethane in preparing polyurethane elastomers.

Another objective of this invention is to provide a use of the polyurethane in preparing microcellular polyurethane elastomers. Another objective of this invention is to provide a use of the polyurethane in preparing shoe sole, carpet, roller, sealing strip, coating, tire, wiper, steering wheel or gasket.

In the present invention, preparing the polyurethane by adding polybutadiene in accordance with the requirement into the polyols and/or isocyanates will significantly improve the abrasion resistance thereof. Furthermore, comparing to the prior art, the polyurethane obtained in this invention does not have obvious pin holes, but possesses good surface quality. Drawing Description

Fig 1 A cross sectional view of a polyurethane with surface a-a' prepared in according with the prior art.

Fig 2 A picture of the surface a-a' of the polyurethane, the magnification is 500: 1

Fig 3 A cross sectional view of a polyurethane with surface b-b' prepared in according with the present invention.

Fig 4 Picture showing polyurethane surface containing polybutadiene, A picture of the surface b-b' of the polyurethane, the magnification is 500: 1.

Detailed Mode to Carry Out the Invention

The present invention provides a method for preparing polyurethane with improved abrasion resistance by adding a polybutadiene with special requirement. In this invention, the polybutadiene met with special requirement can be used to prepare polyols and/or isocyanates for preparing polyurethane.

In the present invention, the polybutadiene is prepared by polymerization of butadiene. The polybutadiene comprises 1,2-butene structure unit (B), 2,3-(cis) butane structure unit (A) and 2,3 (trans)-butene structure unit (C). In the polybutadiene, the amount of the 1 ,2-butane structure unit is less than 30 wt.%, preferably 10-25 wt.%, based on 100 wt.% of the polybutadiene. In the polybutadiene, the amount of the 2,3 (trans)-butene structure unit is more than the amount of the 2,3 (cis)-butene structure unit, and the amount of the 2,3 (trans)-butene structure unit is 40-50 wt.%, preferably 43-50 wt.%, based on 100 wt.% of the polybutadiene. The polybutadiene can be specified by a general formula (1):

B

C¾)

CH= CH CH=CH /

/ \

-*CH ₂ CH ₂ )~ -(CH ₂ -CH†(CH2 / CH ₂ — CH

(1) The amount of the polybutadiene is 0.05-5 wt.% , preferably 0.1-4 wt.%, more preferably 0.2-3 wt.%, based on 100 wt.% of the A, B, C and D.

In the present invention, the isocyanate can be specified by a general formula R(NCO) _n , wherein R represents (cyclo) aliphatic alkylene comprising 2-18 carbon atoms, aromatic alkylene comprising 6-15 carbon atoms or (cyclo) aliphatic aromatic alkylene comprising 8-15 carbon atoms, n=2-4.

The isocyanate can be selected from, but not be limited to, ethylene diisocyanate, 1 ,4- tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), 1 ,2-dodecane diisocyanate, cyclobutane-l,3-diisocyanate, cyclohexane 1,3 -diisocyanate, 1,4-diisocyanate, l-isocyanato-3,3,5- trimethyl-5-isocyanatomethyl-cyclohexane, 2,4-hexahydrotoluene diisocyanate, hexahydro-1,3- phenylene diisocyanate, hexahydro-l,4-phenylene diisocyanate, perhydro-2,4-diphenylmethane diisocyanate, perhydro-4,4'-diphenylmethane diisocyanate, 1 ,3- phenylene diisocyanate, 1 ,4- phenylene diisocyanate, 1 ,4-durol diisocyanate, 1,4-stilbene diisocyanate, 3,3'-dimethyl-4,4'- biphenylene diisocyanate, toluene 2,4-diisocyanate (TDI), 2,6-diisocyanate (TDI), diphenylmethane-2,4'-diisocyanate (MDI), diphenylmethane-2,2'-diisocyanate (MDI), diphenylmethane-4,4'-diisocyanate (MDI), naphthylene-l,5-diisocyanate (NDI), their mixture, their isomer, the mixture of they and their isomer.

The polyisocyanate may also include polyisocyanate modified by carbon diamine, allophanate and isocyanate. The polyisocyanate can be selected from, but not be limited to, diphenylmethane diisocyanate, diphenylmethane diisocyanate modified by carbodiimide, their mixture, their isomer, or the mixture of they and their isomer.

The polyisocyanate may also include isocyanate prepolymer. The NCO content of the isocyanate prepolymer can be selected from, but not be limited to, 5-30 wt.%, preferably 10- 25 wt.%, based on 100 wt.% of the prepolymer.

In the present invention, the polyol can comprise one or more polyols, the average molecular weight of the polyol can be selected from, but not be limited to, 1000-10000, and the functionality of the polyol can be selected from, but not be limited to, 1-5, preferably 1.8 - 3.2.

In the present invention, the polyol can be selected from, but not be limited to, polyester polyols, polyether polyols, polycarbonate polyols, polymer polyols or their mixture. The polyester polyols can be produced from the reaction of dicarboxylic acids or dicarboxylic acid anhydrides with polyhydric alcohols. The dicarboxylic acids can be selected from, but not be limited to, aliphatic carboxylic acids containing 2 to 12 carbon atoms, such as succinic acid, malonic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, decane-dicarboxylic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, and their mixture. The dicarboxylic acid anhydrides can be selected from, but not be limited to, phthalic anhydride, terachlorophthalic anhydride, maleic anhydride, and their mixture. The polyhydric alcohols can be selected from, but not be limited to, ethanediol, diethylene glycol, 1 ,2-propanediol, 1 ,3-propanediol, dipropylene glycol, 1 ,3-methylpropanediol, 1 ,4-butanediol, 1 ,5-pentanediol, 1 ,6-hexanediol, neopentyl glycol, 1 , 10-decanediol, glycerol, trimethylol-propane, or their mixture. The polyester polyols, can also includes the polyester polyols prepared by lactones, for example, polyester polyols prepared by lactones can be selected from, but not be limited to, e-caprolactone. The polyether polyols can be produced by known process, for example, by the reaction of alkene oxides with polyhydric alcohol starters in the presence catalysts. The catalysts can be selected from, but not b e limited to, alkali hydroxides, alkali alkoxides, antimony pentachloride, boron fluoride etherate, or their mixture. The alkene oxides, can be selected from, but not be limited to, tetrahydrofuran, ethylene oxide, 1 ,2-propylene oxide, 1 ,2- and 2,3-butylene oxide, styrene oxide, or their mixture. The polyhydric alcohol starters can be selected from, but not be limited to, polyhydric compounds, such as, water, ethylene glycol, 1,2- and 1 ,3-propanediols, 1 ,4-butanediol, diethylene glycol, trimethylol-propane, or their mixture.

The polycarbonate polyols can be selected from, but not be limited to, polycarbonate diols. The polycarbonate diols can be produced by the reaction of diols with dialkyl or diaryl carbonates or phosgene. The diols can be selected from, but not be limited to, 1 ,2- propanediol, 1 ,3-propanediol, 1 ,4-butanediol, 1 ,5-pentanediol, 1 ,6-hexanediol, diethylene glycol, trioxyethylene glycol, or their mixture. The dialkyl or diaryl carbonates can be selected from, but not be limited to, diphenyl carbonate. The polymer polyols can be selected from, but not be limited to, polymer-polyether polyols, polymer-polyester polyols, or their mixture.

The polymer-polyester polyols are graft po lymer p o lyo ls b ase d on polyesters or polyetheresters, preferably graft polymer polyol and polyester polyol dispersion. The graft polymer polyol can be selected from, but not be limited to, graft polymer polyol based on styrene and/or acrylonitrile; The styrene and/or acrylonitrile can be produced by the in situ polymerisation of acrylonitrile, styrene, or the mixture of styrene and acrylonitrile; In the mixture of styrene and acrylonitrile, the ratio by weight between the styrene and acrylonitrile is 90: 10-10:90, preferably 70:30-30:70. The polymer polyester polyol dispersion comprises disperse phase, for example, containing inorganic fillers, polyureas, polyhydrazides, polyurethane containing tertiary amino groups in bonded form and/or melamine. The amount of the disperse phase is 1 -50 wt.%, preferably 1 -45 wt.%, based on 100 wt.%) of the polymer- polyester polyol.

The polymer-polyether polyols are polymer-modified polyether polyols, preferably graft polyether polyols and polyether polyol dispersion. The graft polyether polyols can be selected from, but not be limited to, graft polymer polyol based on styrene and/or acrylonitrile; The styrene and/or acrylonitrile can be produced by the in situ polymerisation of acrylonitrile, styrene, or the mixture of styrene and acrylonitrile; In the mixture of styrene and acrylonitrile, the ratio by weight between the styrene and acrylonitrile is 90: 10-10:90, preferably 70:30-30:70. The polymer polyether polyol dispersion comprises disperse phase, for example, containing inorganic fillers, polyureas, polyhydrazides, polyurethane containing tertiary amino groups in bonded form and/or melamine. The amount of the disperse phase is 1-50 wt.%, preferably 1 -45 wt.%, based on 100 wt.% of the polymer-polyester polyol.

In the present invention, the chain extenders are active hydrogen atom containing compounds having a molecular weight less than 800, preferably 18-400. The active hydrogen atom containing compounds can be selected from, but not be limited to, alkanediols, dialkylene glycols, polyalkylene polyols, or their mixture, such as, ethanediol, 1 ,4-butanediol, 1 ,6- hexanediol, 1 ,7-heptanediol, 1 ,8-octanediol, 1 ,9-nonanediol, 1 , 10-decanediol, diethylene glycol, dipropylene glycol, polyoxyalkylene glycols, or their mixture. The active hydrogen atom containing compounds can also comprises branched chain and/or unsaturated alk an e di o l s , suc h as 1 , 2-propanediol, 2-methyl-l,3-propanediol, 2,2-dimethyl- l ,3- prop anedi o l, 2-butyl-2-ethyl- 1 ,3 -propanediol, 2-butene-l,4-diol, 2-butyne-l,4-diol, alkanolamines, N-alkyldialkanolamines; the N-alkyldialkanolamines can be selected from, but not be limited to, ethanolamine, 2-aminopropanol, 3-amino-2,2-dimethylpropanol, N- methyl-diethanolamines, N-ethyl-diethanolamines, or their mixture. The active hydrogen atom containing compounds can also includes aliphatic amines, aromatic amines, such as

1,2-e th y l e n e d i ami n e , 1 , 3-propylenediamine, 1 ,4-butylenediamine, 1 ,6- hexamethylenediamine, isophoronediamine, 1 ,4-cyclohexamethylenediamine, N,N'-diethyl- phenylenediamine, 2,4-diaminotoluene, 2,6-diaminotoluene, or their mixture. The amount of the chain extenders is 1 -50 wt.%, based on 100 wt.% of the polyols and chain extenders used in the reaction system.

In the present invention, the blowing agents can be selected from physical blowing agents or chemical blowing agents, preferably but not b e limited to water, halohydrocarbons, hydrocarbons, and gases. The halohydrocarbons can be selected from, but not be limited to, monochloro difuloromethane, dichloromonofluor omethane, dichlor ofluor omethane, trichloroflur omethane, or their mixture. The hydrocarbons can be selected from, but not be limited to, butane, pentane, cyclopentane, hexane, cyclohexane, heptane, or their mixture. The gases can be selected from, but not be limited to, air, C0 ₂ , and N ₂ . Preferably, the blowing agent is water. The amount of the blowing agent is determined by the density of polyurethanes. The density of the polyurethane can be selected from, but not be limited to, 100-1200 kg/m ³ . In the present invention, the catalysts can be selected from, but not be limited to, amine catalysts, organo-metallic compounds, or their mixture. The amine catalysts can be selected from, but not be limited to, triethylamine, tributylamine, N-methylmorpholine, N- ethylmorpholine, Ν,Ν,Ν',Ν'-tetramethyl-ethylenediamine, pentamethyldiethylene-triamine, N,N-methylbenzylamine, Ν,Ν-dimethylbenzylamine, or their mixture. The organo-metallic compounds catalysts can be selected from, but not be limited to, organo-tin compounds, such as, tin(II) acetate, tin(II) octoate, tin(II) ethylhexonate, tin(II) laurate, dibutyltin oxide, dibutyltin dichloride, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate, dioctyltin diacetate, or their mixture. The amount of the said catalyst is 0.001 - 10 wt.%, based on 100 wt.% of the polyols used in the reaction system. In the present invention, the surfactants can be selected from, but not be limited to, polyoxyalkylene derivatives of siloxane. The amount of the said surfactants is 0.01 to 8 wt.%, based on 100 wt.% of the polyols and chain extenders used in the reaction system.

In the present invention, the pigments and/or fillers can be selected from, but not be limited to, calcium carbonate, graphite, carbon black, titanium dioxide, iron oxide, alumina trihydrate, wollastonite, glass fibers, polyester fibers, polymeric fibers.

The density of the polyurethane provided in the present invention is, 100-1200 kg/m ³ , preferably 250-1200 kg/m ³ .

The abrasion resistance of the polyurethane provided in the present invention is, less than or equal to 215 mg, preferably 10- 150 mg, more preferably 25-100 mg, tested in accordance with IS04649.

Fig 1 is a cross sectional view of a polyurethane with surface a-a' prepared in according with the prior art. Fig 2 is a picture of the surface a-a' of the polyurethane, the magnification is 500: 1. According to Fig 1, many non-closed pinholes can be found on the surface a-a' of the polyurethane prepared in according with the prior art. These non-closed pinholes, which can be found in Fig 2 as sunken parts on the polyurethane surface a-a' (so called "pinhole sunken parts"), will be harm to the appearance of the polyurethane products.

The polyurethane provided in accordance with the present invention possesses good surface quality. Fig 3 is a cross sectional view of a polyurethane with surface b-b' prepared in according with the present invention. Fig 4 is a picture of the surface b-b' of the polyurethane, the magnification is 500: 1. According to Fig 3, no open pinhole can be found on the surface b-b' of the polyurethane prepared in accordance with the present invention. In Fig 4, there is no obvious pinhole sunken part on the surface b-b' of the polyurethane, therefore, the polyurethane prepared in accordance with the present invention possesses good product appearance.

The polyurethane provided in the present invention can be used to prepare shoe sole, carpet, roller, sealing strip, coating, tire, wiper, steering wheel or gasket.

Examples

The Examples and the methods provided in the present invention are illuminative but not be limited.

The materials mentioned in the description

Polyol 1 Polyether polyol, Molecular weight 4000, hydroxyl value 28 mg KOH/g, from Bayer MaterialScience;

(Bayflex 0650)

Polyol 2 Polymer p olyether polyol, hydroxyl value 20 mg

KOH/g, from Bayer MaterialScience;

(Hyperlite E-850)

Polyol 3 Polyester polyol, hydroxyl value 48 mg KOH/g, from

Bayer MaterialScience;

(Bayflex FW30FX102)

EG Ethyl Glycol;

BD 1,4-butanediol

Polybutadiene A Polybutadiene, average molecular weight 6600, 1 -2 butene content ( 12%) and 2,3 (trans) butene content

(LBR 307)

(50%) from Kuraray;

Polybutadiene B Polybutadiene, average molecular weight 13000, 1 -2 butene content (21%) and 2,3 (trans) butene content (Ricon 134) (45%) from Sartomer; Dabco EG Amine catalyst, from Air Products; Dabco S 25 Amine catalyst, from Air Products; Dabco 1028 Amine catalyst, from Air Products; Fomrez UL- 1 Tin catalyst, from Momentive; Dabco DC 193 Silicone surfactant, from Air Products; Dabco DC 198 Silicone surfactant, from Air Products; ISO 1 Polyether modified polyisocyanate, isocyanate content

19.9 wt.%, from Bayer MaterialScience;

(Desmodur VP.PU 10isl4C) ISO 2 Polyester modified polyisocyanate, isocyanate content

19.0 wt.%, from Bayer MaterialScience;

(Desmodur VP.PU 0926)

ISO 3 Adding 5 wt.% of Polybutadiene A in ISO 1

ISO 4 Adding 5 wt.% of Polybutadiene A in ISO 2

In the Examples, PENDRAULIK agitator purchased from PENDRAULIK Company was used as a mixing device.

Method for preparing polyurethane

Reaction components B, C and D (and the optional E) were blended by a stirrer to obtain a blend.

The blend could be mixed and reacted with component A by two methods. In the first method, the blend was mixed and reacted with component A by a stirrer. In the second method, the blend was mixed and reacted with component A by a two component or a multi component mixing device. The mixing device could be a high pressure machine or a low pressure machine, preferably low pressure machine. The mixing process could be a double- stream mixing process or a multi-stream mixing process. For example, the pigment could be introduced as a third stream to change the color of the mixture quickly.

Molding techniques and equipments of polyurethane compounds were well known to those skilled in the art, especially using such learned treatises as Saunders and Fish, Polyurethane Chemestry and Technology (Part II) and Oertel, Polyurethane Handbook.

Test Method

The density result of the polyurethane provided in this invention was tested in accordance with DIN EN ISO 845.

The hardness result of the polyurethane provided in this invention was tested in accordance with DIN 53505.

The abrasion resistance result of the polyurethane provided in this invention was tested in accordance with IS04649.

The tensile strength result of the polyurethane provided in this invention was tested in accordance with DIN 53504.

The elongation result of the polyurethane provided in this invention was tested in accordance with DIN 53504.

The trouser tear result of the polyurethane provided in this invention was tested in accordance with DIN ISO 34.

The ross flex result of the polyurethane provided in this invention was tested in accordance with ISO 5423.

Example E1-E12, Comparative Examples C1-C4

Preparing the polyurethanes in Example E 1 -E12 and Comparative Examples 1 -4 in accordance with the materials and amounts thereof listed in Table 1 and Table 2.

Firstly, mixing the polyols and the additives in accordance with the amounts listed in the Table 1 and Table 2 at speed of 1400 rpm equably (the additives may optionally comprise chain extenders, blowing agents, surfactants, pigments or fillers). Thereafter, mixing the obtained mixture, which comprises the polyols and the additives, with the isocyanates listed in accordance with the amounts listed in Table 1 and Table 2 at speed of 4200 rpm at 25°C, then introducing into a sheet-shaped aluminum mold with dimensions approximately 200mm x 200mm x 10mm, wherein the mold was controlled at 50°C, closing the mold, foaming and curing for 5 minutes, removing from the mold and obtaining a polyurethane. The obtained polyurethane was left at room temperature for at least 48 hours before undergoing testing, the properties of the polyurethane was listed in the Table 1 and Table 2.

Table 1 Preparation of Polyurethane

El E2 E3 E4 E5 E6 E7 CI C2 C3

Polyol 1 78.22 76.22 74.22 69.22 79.22 76.42 76.02 79.22 79.42 79.02

Polyol 2 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00

BD 8.60 8.60 8.60 8.60 8.60 8.60 8.60 8.60 8.60 8.60

Dabco S-25 1.20 1.20 1.20 1.20 1.20 1.20 1.20 1.20 1.20 1.20

Dabco 1028 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40

Dabco DC 198 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20

Fomrez UL-1 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03

Polybutadiene 1 1.00 3.00 5.00 10.00 0.00 3.00 3.00 0.00 0.00 0.00

Water 0.35 0.35 0.35 0.35 0.35 0.15 0.55 0.35 0.15 0.55

Total 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00

ISO l 60 60 59 58 - 58 64 60 58 64

ISO 3 (Containing 5 wt.% of Polybutadiene A) - - - - 64 - - - - -

Density (kg/m ³ ) 600 600 600 600 600 900 400 600 900 400

Hardness (Shore A) 55 55 55 56 55 73 35 55 73 35

Abrasion (mg) 215 69 32 29 48 50 39* 350 162 250*

*Test Method ISO 4649 , half way (20meters).

Table 2 Preparation of Polyurethane

E8 E9 E10 Ell E12 C4

Polyol 3 89.30 87.30 85.30 80.30 90.30 90.30

EG 7.50 7.50 7.50 7.50 7.50 7.50

Dabco EG 1.50 1.50 1.50 1.50 1.50 1.50

Dabco DC 193 0.20 0.20 0.20 0.20 0.20 0.20

Water 0.50 0.50 0.50 0.50 0.50 0.50

Polybutadiene 1 1.00 3.00 5.00 10.00 0.00 0.00

Total 100.00 100.00 100.00 100.00 100.00 100.00

ISO 2 80 79 79 77 - 80

ISO 4(containing 5 wt.% of Polybutadiene A) - - - - 83 -

Density (kg/m ³ ) 500 500 500 500 500 500

Hardness (Shore A) 54 54 54 54 54 54

Abrasion (mg) 66 38 28 27 27 250

In Example E1 -E4 and E8-E11 , the polyurethane was prepared by adding the polybutadiene in accordance with the requirements of this invention into the polyols for preparing the polyurethane. The test results illustrated that the obtained polyurethanes possess improved abrasion resistance.

In Example E5 and El 2, the polyurethane was prepared by adding the polybutadiene in accordance with the requirements of this invention into the isocyanates for preparing the polyurethane. The test results illustrated that the obtained polyurethanes possess improved abrasion resistance.

In Example E2, E6 and E7, different polyurethane with different densities were prepared by adding the polybutadiene in accordance with the requirements of this invention. The test results illustrated that the obtained polyurethanes possess improved abrasion resistance. Example E13-E14, Comparative Examples C5

Preparing the polyurethanes in Example E 13-E14 and Comparative Example C 5 in accordance with the materials and amounts thereof listed in Table 1 and Table 2.

Firstly, mixing the polyols and the additives in accordance with the amounts listed in the Table 3 at speed of 1400 rpm equably (the additives may optionally comprise chain extenders, blowing agents, surfactants, pigments or fillers). Thereafter, mixing the obtained mixture, which comprised the polyols and the additives, with the isocyanates listed in accordance with the amounts listed in the Table 3 at speed of 4200 rpm at 25°C, then intro ducing into a she et-shaped aluminum mold with dimensions approximately 200mmx200mmxl0mm, wherein the mold was controlled at 50°C, closing the mold, foaming and curing for 5 minutes, removing from the mold and obtaining a polyurethane. The obtained polyurethane was left at room temperature for at least 48 hours before undergoing testing, the properties of the polyurethane was listed in the Table 3.

Table 3 Preparation of Polyurethane

E13 E14 C5

Polyol 1 76.22 76.22 79.22

Polyol 2 10.00 10.00 10.00

BD 8.60 8.60 8.60

Dabco S 25 1.20 1.20 1.20

Dabco 1028 0.40 0.40 0.40

Dabco DC 198 0.20 0.20 0.20

Fomrez UL-1 0.03 0.03 0.03

Polybutadiene A 3.00 - -

Polybutadiene B - 3.00 -

Water 0.35 0.35 0.35

Total 100.00 100.00 100.00

ISO l 60 60 60 Density (kg/m ³ ) 600 600 600

Hardness (Shore A) 63 63 60

Abrasion (mg) 57 52 350

Ross flex (100,000 cycles @ )

Room Temperature) <4mm <4mm <4mm

Tensile Strength (Mpa) 4.8 4.6 5.0

Elongation (%) 419 433 513

Trousers Tear (kN/m) 9.2 8.3 7.9

In Example El 3 and El 4, polyurethanes were prepared by adding the polybutadienes with different average molecular weights in accordance with the requirements of this invention. The test results illustrated that the obtained polyurethanes possess improved abrasion resistance.

Although the present invention is illustrated through Examples, it is not limited by these Examples in any way. Without departing from the spirit and scope of this invention, those skilled in the art can make any modifications and alternatives. And the protection of this invention is based on the scope defined by the claims of this application.