Articles formed with biodegradable materials and biodegradability characteristics thereof
Described herein are strength characteristics and biodegradation of articles produced using one or more petrochemical-based polymers and one or more carbohydrate-based polymers. A compatibilizer can optionally be included in the article. In some cases, the article can include a film or bag.
1. An article comprising:
polymeric content comprising:
a starch-based polymeric material formed from at least a first starch and a plasticizer; and
one or more polyolefins selected from the group consisting of polyethylene, polypropylene, and polystyrene;
wherein at least 25% of carbon atoms of the one or more polyolefins become at least one of carbon dioxide or methane at about 180 days in simulated landfill conditions or simulated compost conditions;
wherein the starch-based polymeric material has a crystallinity of less than about 20%, and resists recrystallization, a water content no greater than 2% by weight, and the starch-based polymeric material and one or more polyolefins exhibit a lack of sea-island features when blended together to form the article.
2. The article of claim 1 , wherein the starch-based polymeric material is formed from the first starch and a second starch, wherein the first starch comprises or is derived from one of potato starch, corn starch, or tapioca starch; and the second starch comprises or is derived from a different one of potato starch, corn starch, or tapioca starch.
3. The article of claim 2 , wherein a first amount of the first starch comprises from about 10% by weight to about 50% by weight of a mixture of starches from which the starch based polymeric material is formed, and a second amount of the second starch comprises from about 50% by weight to about 90% by weight of a mixture of starches from which the starch-based polymeric material is formed.
4. The article of claim 1 , further comprising a compatibilizer.
5. The article of claim 4 , wherein the compatibilizer is present in an amount of up to 8% by weight of the article.
6. An article comprising:
polymeric content comprising:
a starch-based polymeric material formed from at least a first starch and a plasticizer; and one or more polyolefins selected from the group consisting of polyethylene and polypropylene;
wherein at least about 25% of carbon atoms of the one or more polyolefins become at least one of carbon dioxide or methane within 3 years in simulated landfill conditions or simulated compost conditions;
wherein the starch-based polymeric material has a crystallinity of less than about 20%, and resists recrystallization, a water content no greater than 2% by weight, and the starch-based polymeric material and one one or more polyolefins exhibit a lack of sea-island features when blended together to form the article.
7. The article of claim 1 wherein the article contains about 20% to about 40% percent by weight of the starch-based polymeric material and about 60% to about 80% by weight of the polyolefin.
8. The article of claim 7 wherein the polyolefin comprises polyethylene.
9. The article of claim 1 wherein the plasticizer is glycerin.
10. The article of claim 1 wherein the polyolefin is polystyrene or polypropylene.
11. The article of claim 1 wherein at least 30% of the carbon atoms of the polyolefin become at least one of carbon dioxide or methane within three years under simulated landfill, or simulated compost conditions.
12. The article of claim 1 wherein the article is formed from a starch-based polymeric material containing from 0.4% to 2% by weight water.
13. The article of claim 1 wherein the article is formed from a starch-based polymeric material containing less than about 1% by weight water.
14. The article of claim 1 wherein the article is formed from a starch-based polymeric material having a crystallinity of less than about 10%.
15. The article of claim 1 wherein the polyolefin comprises polypropylene.
16. The article of claim 1 wherein the polyolefin comprises polystyrene.
17. The article of claim 6 wherein the article contains about 5% to about 20% by weight of the starch-based polymeric material and about 50% to about 95% by weight of the polyolefin.