Webinar Series # 4 as a series of events commemorating the 64th Dies Natalis of the Department of Chemistry, FMIPA, UNY, which was held on Saturday, October 17, 2020. Participants registered in this webinar were 299 people with varied backgrounds ranging from lecturers, teachers , students, researchers in the field of chemistry, etc. who come from all over Indonesia. The speaker who filled the webinar activity this time was Prof. Dr. Azlan Kamari from Sultan Idris Education University, Malaysia and Prof. Dr. Endang Widjajanti from Yogyakarta State University. The theme raised in this webinar series # 4 is Polymer Applications in Life.

Prof. Dr. Azlan Kamari conveyed about Biofilm Innovation for Food Packaging. According to Prof. Dr. Azlan Kamari, based on his weaknesses, biopolymers cannot be used as food wrappers by themselves, biopolymers require additional ingredients including: (1) natural additives such as plant extracts, essential oil, cinnamaldehyde, etc.); (2) nanomaterials (TiO2, AgO, ZnO, GO, etc.); (3) clays and minerals (bentonite, boehmite, etc.); and (4) Vitamins (C, E, etc.).

As for Prof. Dr. Endang Widjajanti conveyed about Nata-based Cellulose Membrane Applications in Various Fields. Prof. Endang Widjajanti said that there are several applications of cellulose membranes from nata, including: (1) the food industry (pudding, edible film / sausage, supplements); (2) energy (electrolyte membrane); (3) biotechnology (adsorbent, biosensor / biofuel, for cell immobilization; (4) environment (waste treatment); (5) paper industry; (6) textile industry; (7) cosmetic industry (mask); (8) pharmaceutical industry (drug delivery, tissue replacement), and (9) nanoparticles (semiconductors, thermoplastics).