TECHNICAL FIELD

[001] This disclosure generally relates to biodegradable devices, and more particularly to biodegradable devices comprising a polylactic acid polymer and a lignocellulosic biomass, and further including methods of making the same.

BACKGROUND

[002] Conventional plastic materials, such as polyethylene and polypropylene, are derived from polymers based on petroleum sources, and currently account for about 90 percent of global plastic production. These petroleum derived plastics require much time to breakdown, and in some instances never breakdown, and thus are generally considered non-biodegradable.

Accordingly, once disposed into the environment, plastics based on polymers derived from petroleum sources may pose a serious threat to land and aquatic habitats.

[003] A means to resolve this issue is to manufacture plastics utilizing polymers that are more biodegradable than those derived from petroleum sources. One such polymer is polylactic acid

(PLA), and it is derived from plant-based sources. Plastics derived from plant-based sources are known in the art as bioplastics.

[004] Global bioplastic production is expected to increase from 2.11 million tons in 2018 to

2.62 million tons in 2023. Of this tonnage, about 60 percent (1.572 million tons) is expected to be created utilizing PLA by 2023. For better or worse, PLA is generally created by fermenting starches or sugars derived from com, cassava, or sugar cane, which are primary food sources to many persons around the world. Accordingly, until such time an economical alternate pathway to creating PLA from food sources is fleshed-out, a need exists to create a bioplastic blend that can be utilized to manufacture a biodegradable device that exhibits as good as, or better than, biodegradability than biodegradable devices manufactured with PLA alone. This, in turn, will free up com, cassava, or sugar cane for use as a food source that would otherwise be used in the manufacture of biodegradable devices.

[005] The present disclosure is therefore directed to overcoming one or more problems set forth above and/or other problems associated with known biodegradable devices.

SUMMARY

[006] In accordance with one aspect of the present disclosure, a bioplastic blend is disclosed.

The bioplastic blend may comprise a polylactic acid polymer and a lignocellulosic biomass.

The lignocellulosic biomass may be a particulate lignocellulosic biomass, and the particulate lignocellulosic biomass may have an average particle size less than or equal to 60 micrometers.

Alteratively, the particulate lignocellulosic biomass may have an average particle size less than or equal to 50 micrometers.

[007] The particulate lignocellulosic biomass may comprise greater than or equal to 50 percent by weight of the bioplastic blend. The particulate lignocellulosic biomass may even be greater than or equal to 60 percent by weight of the bioplastic blend. Further, the particulate lignocellulosic biomass may be selected from at least one of the following group, consisting of switch grass lignocellulosic biomass, elephant grass lignocellulosic biomass, miscanthus grass lignocellulosic biomass, date palm tree lignocellulosic biomass, willow tree lignocellulosic biomass, poplar tree lignocellulosic biomass, and sawmill lignocellulosic biomass.

[008] The bioplastic blend may additionally include a plasticizer. The plasticizer may be selected from the group consisting of at least one of the group consisting of epoxidized palm oil, epoxidized palm olein, epoxidized soybean oil, poly(ethylene glycol), 1-lactide, triethyl citrate, acetyl tributyl citrate, di-2-ethylhexyl adipate, diisodecyl adipate, di-2-ethylhexyl azelate, dipropylene glycol dibenzoate, tricresyl phosphate, cresyl diphenyl phosphate, 2- ethylhexyl diphenyl phosphate, di-n-octyl phenyl phosphate, tri-n-hexyl phosphate, diethyl phthalate, butyl benzyl phthalate, di-2-ethylhexyl phthalate, diisodecyl phthalate, di-2- ethylhexyl sebacate, and di-2-ethylhexyl terephthalate.

[009] In accordance with another aspect of the present disclosure, a biodegradable device is disclosed. The biodegradable device may comprise a polylactic acid polymer and a lignocellulosic biomass. The lignocellulosic biomass may be a particulate lignocellulosic biomass, and the particulate lignocellulosic biomass may have an average particle size less than or equal to 60 micrometers. Alternatively, the particulate lignocellulosic biomass may have an average particle size less than or equal to 50 micrometers.

[010] The particulate lignocellulosic biomass may comprise greater than or equal to 50 percent by weight of the biodegradable device. The particulate lignocellulosic biomass may even be greater than or equal to 60 percent by weight of the biodegradable device. Further, the lignocellulosic biomass may be selected from at least one of the following group, consisting of switch grass lignocellulosic biomass, elephant grass lignocellulosic biomass, miscanthus grass lignocellulosic biomass, date palm tree lignocellulosic biomass, willow tree lignocellulosic biomass, poplar tree lignocellulosic biomass, and sawmill lignocellulosic biomass.

[011] The biodegradable device may additionally include a plasticizer. The plasticizer may be selected from the group consisting of at least one of the group consisting of epoxidized palm oil, epoxidized palm olein, epoxidized soybean oil, poly(ethylene glycol), 1-lactide, triethyl citrate, acetyl tributyl citrate, di-2-ethylhexyl adipate, diisodecyl adipate, di-2-ethylhexyl azelate, dipropylene glycol dibenzoate, tricresyl phosphate, cresyl diphenyl phosphate, 2- ethylhexyl diphenyl phosphate, di-n-octyl phenyl phosphate, tri-n-hexyl phosphate, diethyl phthalate, butyl benzyl phthalate, di-2-ethylhexyl phthalate, diisodecyl phthalate, di-2- ethylhexyl sebacate, and di-2-ethylhexyl terephthalate.

[012] In accordance with an additional aspect of the present disclosure, a method of manufacturing a biodegradable device is disclosed. Generally, the method may include the steps of comminuting a starting lignocellulosic biomass to create a particulate lignocellulosic biomass, the particulate lignocellulosic biomass having an average particle size less than the starting lignocellulosic biomass. Subsequently the particulate lignocellulosic biomass may be mixed with a polylactic acid polymer in an extruder to create a bioplastic blend. Finally, the bioplastic blend may be molded to create the biodegradable device. The molding step may be selected from the group consisting of injection molding and compression molding.

[013] The particulate lignocellulosic biomass used to create the biodegradable device may have an average particle size less than or equal to 60 micrometers. Alternatively, the particulate lignocellulosic biomass used to create the biodegradable device may have an average particle size less than or equal to 50 micrometers. The particulate lignocellulosic biomass may comprise greater than or equal to 50 percent by weight of the biodegradable device. In other instances, the particulate lignocellulosic biomass may comprise greater than or equal to 60 percent by weight of the biodegradable device.

[014] Additionally, the method of creating the biodegradable device may further include the step of sieving the particulate lignocellulosic biomass prior to mixing it with the polylactic acid polymer to create a sieved particulate lignocellulosic biomass, the sieved particulate lignocellulosic biomass having an average particle size less than or equal to 60 micrometers.

In other instances, the sieved particulate lignocellulosic biomass may have an average particle size less than or equal to 50 micrometers.

[015] Additionally, the mixing step may further include mixing a plasticizer with the lignocellulosic biomass and the polylactic acid polymer in the extruder to create the bioplastic blend, the plasticizer selected from at least one of the group consisting of epoxidized palm oil, epoxidized palm olein, epoxidized soybean oil, poly(ethylene glycol), 1-lactide, triethyl citrate, acetyl tributyl citrate, di-2-ethylhexyl adipate, diisodecyl adipate, di-2-ethylhexyl azelate, dipropylene glycol dibenzoate, tricresyl phosphate, cresyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, di-n-octyl phenyl phosphate, tri-n-hexyl phosphate, diethyl phthalate, butyl benzyl phthalate, di-2-ethylhexyl phthalate, diisodecyl phthalate, di-2-ethylhexyl sebacate, and di-2-ethylhexyl terephthalate.

BRIEF DESCRIPTION

[016] FIG. 1 is schematic illustrating an exemplary bioplastic blend made in accordance with the present disclosure.

[017] FIG. 2 is a flowchart illustrating exemplary steps of a method for manufacturing a biodegradable device utilizing a bioplastic blend made in accordance with the present disclosure.

[018] FIG. 3 is a flowchart illustrating exemplary steps of an alternative method for manufacturing a biodegradable device utilizing a bioplastic blend made in accordance with the present disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE

[019] Various aspects of the disclosure will now be described with reference to the drawings. wherein like reference numbers refer to like elements, unless specified otherwise. Referring to FIG. 1, a schematic of an exemplary bioplastic blend 10 is illustrated, according to an aspect of the disclosure. As represented therein, the bioplastic blend 10 may comprise a polylactic acid polymer 12 and a lignocellulosic biomass 14. As depicted, the polylactic acid polymer 12 may be distinct from the lignocellulosic biomass 14, and more particularly, the lignocellulosic biomass 14 may be a particulate lignocellulosic biomass 16, having a particulate shape and form.

[020] Being a particle, the particulate lignocellulosic biomass 16 may have an average particle size. In one embodiment, the average particle size of the particulate lignocellulosic biomass

16 may be less than or equal to 100 micrometers. In another embodiment, the average particle size of the particulate lignocellulosic biomass 16 may be less than or equal to 99 micrometers,

98 micrometers, 97 micrometers, 96 micrometers, 95 micrometers, 94 micrometers, 93 micrometers, 92 micrometer's, 91 micrometers, 90 micrometers, 89 micrometers, 88 micrometers, 87 micrometers, 86 micrometers, 85 micrometers, 84 micrometers, 83 micrometers, 82 micrometers, 81 micrometers, 80 micrometers, 79 micrometers, 77 micrometers, 76 micrometers, 75 micrometers, 74 micrometers, 73 micrometers, 72 micrometers, 71 micrometers, 70 micrometers, 69 micrometers, 68 micrometers, 67 micrometers, 66 micrometers, 65 micrometers, 64 micrometers, 63 micrometers, 62 micrometers, 61 micrometers, 60 micrometers, 59 micrometers, 58 micrometers, 57 micrometers, 56 micrometers, 55 micrometers, 54 micrometers, 53 micrometers, 52 micrometers, or 51 micrometers. In a preferred embodiment, the average particle size of the particulate lignocellulosic biomass 16 may be less than or equal to 50 micrometers.

[021] Additionally, the particulate lignocellulosic biomass 16 may comprise greater than or equal to 40 percent by weight of the bioplastic blend 10. In another embodiment, the particulate lignocellulosic biomass 16 may comprise greater than or equal to 41 percent by weight, 42 percent by weight, 43 percent by weight, 44 percent by weight, 45 percent by weight, 46 percent by weight, 47 percent by weight, 48 percent by weight, 49 percent by weight, 50 percent by weight, 51 percent by weight, 52 percent by weight, 53 percent by weight, 54 percent by weight, 55 percent by weight, 56 percent by weight, 57 by weight, 58 percent by weight, or 59 percent by weight of the bioplastic blend. In a preferred embodiment, the particulate lignocellulosic biomass 16 may be greater than or equal to 60 percent by weight of the bioplasiic blend 10.

[022] The lignocellulosic biomass 14 and particulate lignocellulosic biomass 16 of the present disclosure may be derived from multiple sources. In one instance the source for the lignocellulosic biomass 14 and the particulate lignocellulosic biomass 16 may be switch grass.

In other instances, the source for the lignocellulosic biomass 14 and particulate lignocellulosic biomass 16 may be elephant grass, miscanthus grass, willow trees, poplar trees and even waste from a sawmill. In a preferred embodiment, the source for the lignocellulosic biomass 14 and particulate lignocellulosic biomass 16 may be date palm trees.

[023] A plasticizer may be added to the bioplastic blend 10, altering its glass transition temperature (T _g ), and thereby modifying the brittleness of any article of manufacture created with the blend 10. While not meant to be exhaustive, some plasticizers that may be utilized with the bioplastic blend 10 include epoxidized palm oil, epoxidized palm olein, epoxidized soybean oil, poly(ethylene glycol), 1-lactide, triethyl citrate, and acetyl tributyl citrate. Other plasticizers that may be used include di-2-ethylhexyl adipate, diisodecyl adipate, di-2- ethylhexyl azelate, dipropylene glycol dibenzoate, tricresyl phosphate, cresyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, di-n-octyl phenyl phosphate, tri-n-hexyl phosphate, diethyl phthalate, butyl benzyl phthalate, di-2-ethylhexyl phthalate, diisodecyl phthalate, di-2-ethylhexyl sebacate, and di-2-ethylhexyl terephthalate. Additionally, a compatible mixture of two or more of the above listed plasticizers may be utilized.

[024] A biodegradable device may be created with the above described bioplastic blend 10.

Without intending to be limiting, biodegradable devices envisioned include single-use disposable utensils. These include forks, knives, spoons, chopsticks, straws, and the like.

Other biodegradable devices envisioned with the bioplastic blend 10 described above include shopping bags, and food containers. INDUSTRIAL APPLICABILITY

[025] In operation, the teachings of the present disclosure can find applicability in many industrial applications, such as, but not limited to, a method of manufacturing a biodegradable device, including forks, knives, spoons, chopsticks, straws, and the like. Referring now to FIG.

2, a flowchart illustrating exemplary steps of a method for manufacturing a biodegradable device utilizing the bioplastic blend 10 of the present disclosure is depicted, and generally referred to by 20. At step 22, a lignocellulosic biomass 14 is comminuted to create a particulate lignocellulosic biomass 16. The particulate lignocellulosic biomass 16 may have an average particle size that is less than or equal to the lignocellulosic biomass 14. The lignocellulosic biomass may be comminuted by any acceptable method, such as by grinding, shearing, ball milling, crushing, and the like.

[026] As described above, the average particle size of the particulate lignocellulosic biomass

16 may be less than or equal to 100 micrometers. In another embodiment, the average particle size of the particulate lignocellulosic biomass 16 may be less than or equal to 99 micrometers,

98 micrometers, 97 micrometers, 96 micrometers, 95 micrometers, 94 micrometers, 93 micrometers, 92 micrometers, 91 micrometers, 90 micrometers, 89 micrometers, 88 micrometers, 87 micrometers, 86 micrometers, 85 micrometers, 84 micrometers, 83 micrometers, 82 micrometers, 81 micrometers, 80 micrometers, 79 micrometers, 77 micrometers, 76 micrometers, 75 micrometers, 74 micrometers, 73 micrometers, 72 micrometers, 71 micrometers, 70 micrometers, 69 micrometers, 68 micrometers, 67 micrometers, 66 micrometers, 65 micrometers, 64 micrometers, 63 micrometers, 62 micrometers, 61 micrometers, 60 micrometers, 59 micrometers, 58 micrometers, 57 micrometers, 56 micrometers, 55 micrometers, 54 micrometers, 53 micrometers, 52 micrometers, or 51 micrometers. In a preferred embodiment, the average particle size of the particulate lignocellulosic biomass 16 may be less than or equal to 50 micrometers. [027] Subsequently, at step 24 the particulate lignocellulosic biomass 16 may be mixed with a polylactic acid polymer 12 in an extruder to create the bioplastic blend 10. The particulate lignocellulosic biomass 16 may comprise greater than or equal to 40 percent by weight of the bioplastic blend 10. In another embodiment, the particulate lignocellulosic biomass 16 may comprise greater than or equal to 41 percent by weight, 42 percent by weight, 43 percent by weight, 44 percent by weight, 45 percent by weight, 46 percent by weight, 47 percent by weight, 48 percent by weight, 49 percent by weight, 50 percent by weight, 51 percent by weight, 52 percent by weight, 53 percent by weight, 54 percent by weight, 55 percent by weight, 56 percent by weight, 57 by weight, 58 percent by weight, or 59 percent by weight of the bioplastic blend 10. In a preferred embodiment, the particulate lignocellulosic biomass 16 may be greater than or equal to 60 percent by weight of the bioplastic blend 10.

[028] Next, at step 26, die bioplastic blend 10 may be molded to create the biodegradable device, such as, but not limited to forks, knives, spoons, chopsticks, straws, and the like. In one instance, the biodegradable device may be manufactured more economically with compression molding, while in another instance the biodegradable device may be manufactured with injection molding. Other molding techniques known in the art are within the scope of this disclosure.

[029] Because the bioplastic blend 10 in method 20 may have varying amounts of particulate lignocellulosic biomass 16, the biodegradable device may comprise greater than or equal to 40 percent by weight, 41 percent by weight, 42 percent by weight, 43 percent by weight, 44 percent by weight, 45 percent by weight, 46 percent by weight, 47 percent by weight, 48 percent by weight, 49 percent by weight, 50 percent by weight, 51 percent by weight, 52 percent by weight, 53 percent by weight, 54 percent by weight, 55 percent by weight, 56 percent by weight, 57 by weight 58 percent by weight, or 59 percent by weight particulate lignocellulosic biomass 16. In a preferred embodiment, the particulate lignocellulosic biomass 16 may comprise greater than or equal to 60 percent by weight of the biodegradable device.

[030] Additionally, the lignocellulosic biomass 14, and thus the particulate lignocellulosic biomass 16, may be derived from multiple sources. In one instance the source for the lignocellulosic biomass 14 and the particulate lignocellulosic biomass 16 may be switch grass.

In other instances, the source for the lignocellulosic biomass 14 and particulate lignocellulosic biomass 16 may be elephant grass, miscanthus grass, willow trees, poplar trees and even waste from a sawmill. In a preferred embodiment, the source for the lignocellulosic biomass 14 and particulate lignocellulosic biomass 16 may be date palm trees.

[031] As described before, a plasticizer may be utilized in the bioplastic blend 10 altering its glass transition temperature (T _g ), thereby modifying the brittleness of any article of manufacture created with the blend 10. Accordingly, the biodegradable device made by method

20 may also include a plasticizer. While not meant to be exhaustive, some plasticizers that may be utilized with the bioplastic blend 10 include epoxidized palm oil, epoxidized palm olein, epoxidized soybean oil, poly(ethylene glycol), 1-lactide, triethyl citrate, and acetyl tributyl citrate. Other plasticizers that may be used include di-2-ethylhexyl adipate, diisodecyl adipate, di-2-ethylhexyl azelate, dipropylene glycol dibenzoate, tricresyl phosphate, cresyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, di-n-octyl phenyl phosphate, tri-n-hexyl phosphate, diethyl phthalate, butyl benzyl phthalate, di-2-ethylhexyl phthalate, diisodecyl phthalate, di-2-ethylhexyl sebacate, and di-2-ethylhexyl terephthalate. Additionally, a compatible mixture of two or more of the above described plasticizers may be utilized.

[032] Referring now to FIG. 3, a flowchart illustrating exemplary steps of an alternative method for manufacturing a biodegradable device utilizing a bioplastic blend 10 made in accordance with the present disclosure is depicted and generally referred to by 30. At step 32, a lignocellulosic biomass 14 is comminuted to create a particulate lignocellulosic biomass. The particulate lignocellulosic biomass 16 may have an average particle size that is less than or equal to the lignocellulosic biomass 14. The lignocellulosic biomass may be comminuted by any acceptable method, such as by grinding, shearing, ball milling, crushing, and the like.

[033] At step 34, the particulate lignocellulosic biomass 16 may be sieved to create a sieved particulate lignocellulosic biomass. The average particle size of the sieved particulate lignocellulosic biomass may be less than or equal to 100 micrometers. In another embodiment, the average particle size of the sieved particulate lignocellulosic biomass may be less than or equal to 99 micrometers, 98 micrometers, 97 micrometers, 96 micrometers, 95 micrometers,

94 micrometers, 93 micrometers, 92 micrometers, 91 micrometers, 90 micrometers, 89 micrometers, 88 micrometers, 87 micrometers, 86 micrometers, 85 micrometers, 84 micrometers, 83 micrometers, 82 micrometers, 81 micrometers, 80 micrometers, 79 micrometers, 77 micrometers, 76 micrometers, 75 micrometers, 74 micrometers, 73 micrometers, 72 micrometers, 71 micrometers, 70 micrometers, 69 micrometers, 68 micrometers, 67 micrometers, 66 micrometers, 65 micrometers, 64 micrometers, 63 micrometers, 62 micrometers, 61 micrometers, 60 micrometers, 59 micrometers, 58 micrometers, 57 micrometers, 56 micrometers, 55 micrometers, 54 micrometers, 53 micrometers, 52 micrometers, or 51 micrometers. In a preferred embodiment, the average particle size of the sieved particulate lignocellulosic biomass may be less than or equal to 50 micrometers. In a preferred embodiment, step 34 takes place before any subsequent steps, such as mixing with a polylactic acid polymer.

[034] Subsequently, at step 36 the sieved particulate lignocellulosic biomass may be mixed with a polylactic acid polymer 12 in an extruder to create the bioplastic blend 10. The sieved particulate lignocellulosic biomass may comprise greater than or equal to 40 percent by weight of the bioplastic blend 10. In another embodiment, the sieved particulate lignocellulosic biomass may comprise greater than or equal to 41 percent by weight, 42 percent by weight, 43 percent by weight, 44 percent by weight, 45 percent by weight, 46 percent by weight, 47 percent by weight, 48 percent by weight, 49 percent by weight, 50 percent by weight, 51 percent by weight, 52 percent by weight, 53 percent by weight, 54 percent by weight, 55 percent by weight, 56 percent by weight, 57 by weight, 58 percent by weight, or 59 percent by weight of the bioplastic blend 10. In a preferred embodiment, the sieved particulate lignocellulosic biomass may be greater than or equal to 60 percent by weight of the bioplastic blend 10.

[035] Next, at step 38, the bioplastic blend 10 may be molded to create the biodegradable device, such as, but not limited to forks, knives, spoons, chopsticks, straws, and the like. In one instance, the biodegradable device may be manufactured more economically with compression molding, while in another instance the biodegradable device may be manufactured with injection molding. Other molding techniques known in the art are within the scope of this disclosure.

[036] Because the bioplastic blend 10 in method 30 may have varying amounts of sieved particulate lignocelliilosic biomass, the biodegradable device may comprise greater than or equal to 40 percent by weight, 41 percent by weight, 42 percent, by weight, 43 percent by weight, 44 percent by weight, 45 percent by weight, 46 percent by weight, 47 percent by weight, 48 percent by weight, 49 percent by weight, 50 percent by weight, 51 percent by weight, 52 percent by weight, 53 percent, by weight, 54 percent by weight, 55 percent by weight, 56 percent by weight, 57 by weight, 58 percent by weight, or 59 percent by weight sieved particulate lignocellulosic biomass. In a preferred embodiment, the sieved particulate lignocellulosic biomass may comprise greater than or equal to 60 percent by weight of the biodegradable device.

[037] Additionally, the lignocellulosic biomass 14, and thus the sieved particulate lignocellulosic biomass, may be derived from multiple sources. In one instance the source for the lignocellulosic biomass 14 and the sieved particulate lignocellulosic biomass may be switch grass. In other instances, the source for the lignocellulosic biomass 14 and sieved particulate lignocellulosic biomass may be elephant grass, miscanthus grass, willow trees, poplar trees and even waste from a sawmill. In a preferred embodiment, the source for the lignocellulosic biomass 14 and sieved particulate lignocellulosic biomass may be date palm trees.

[038] As described before, a plasticizer may be utilized in the bioplastic blend 10 altering its glass transition temperature (T _g ), thereby modifying the brittleness of any article of manufacture created with the blend 10. Accordingly, the biodegradable device created by method 30 may also include a plasticizer. While not meant to be exhaustive, some plasticizers that may be utilized with the bioplastic blend 10 include epoxidized palm oil, epoxidized palm olein, epoxidized soybean oil, poly(ethylene glycol), 1-lactide, triethyl citrate, and acetyl tributyl citrate. Other plasticizers that may be used include di-2-ethylhexyl adipate, diisodecyl adipate, di-2-ethylhexyl azelate, dipropylene glycol dibenzoate, tricresyl phosphate, cresyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, di-n-octyl phenyl phosphate, tri-n-hexyl phosphate, diethyl phthalate, butyl benzyl phthalate, di-2-ethylhexyl phthalate, drisodecyl phthalate, di-2-ethylhexyl sebacate, and di-2-ethylhexyl terephthalate. Additionally, a compatible mixture of two or more of the above described plasticizers may be utilized.

[039] The above description is meant to be representative only, and thus modifications may be made to the embodiments described herein without departing from the scope of the disclosure. Thus, these modifications fall within the scope of the present disclosure and are intended to fall within the appended claims.