Production of polymeric biocomposites from rice endosperm
Starch production yields ~80% endosperm, 8% protein and 12% other by-products, including rice endosperm, the latter being used as a low value-added animal feed.
By mixing rice endosperm with a polysuccinate butylene (PBS) matrix, polymeric materials are obtained. The functional characteristics of these are similar and even improved in aspects such as ductility. Mixing can be done with both the original and the enzymatically treated endosperm.
Rice endosperm has a high content in the form of starch (65%), but may also contain oils and proteins. The PBS compound can be prepared from a mixture of the original waste or from the enzymatically treated waste. This treatment splits the original by-product derived from rice endosperm into a solid waste, suitable for the preparation of polymeric biocompounds, and a supernatant, which contains bioactive molecules with high potential value for application in cosmetics and nutraceuticals due to its polyphenol content. Rice endosperm has good compatibility with the PBS matrix, which can be mixed at 125ºC in amounts between 10-30%. At the functional level, it does not modify the thermal properties and significantly improves its characteristics, making the material more ductile. In particular, hydrolysed rice endosperms improve approximately 100% of the tensile and flexural strength. These results are obtained without the use of compatibilising agents within the matrix polymer or without interfacial fibre modifications. Therefore, rice endosperm can potentially be used as a reinforcing material for the manufacture of biocomposites.
Market deployment considerations