The routine seminar held by the Physics Department-UI on Wednesday, April 15, 2015 raised a topic entitled “Biodegradable Plastic from Cassava Dregs with the Addition of Chitosan from Crab Shells to Improve the Physical Properties of Materials”, with speaker Dr. Djonaedi Saleh. Basically, the discussion of the seminar covered the results of research that had been conducted in the last week. The seminar briefly presented the results of research in the field of materials science in the scope of biomaterial research that he worked on. The seminar was attended by teaching staff and undergraduate, postgraduate and doctoral students.

The following is an abstract of the contents of the seminar that took place:

Plastic materials are important materials in the packaging and manufacturing industries. Currently, the source of plastic raw materials derived from petroleum is starting to be replaced with raw materials derived from plants and animals to reduce pollution and accelerate the degradation process. Biodegradable plastic is a polymer material that is easily decomposed by nature so that it does not produce waste that is harmful to human life. Biodegradable plastic can be produced from materials containing fiber (cellulose) or starch. Cassava dregs (onggok) which are solid waste from the tapioca flour industry contain 35% crude fiber, a little protein and HCN. To make cassava dregs into biodegradable plastic, sorbitol is needed as a plasticizer. Chitosan is an extract of crab shell waste or shrimp skin. By adding chitosan to biodegradable plastic, it will increase tensile strength, tear resistance and delay damage caused by insects and fungi.