Students of FMIPA succeed in making an innovation that is making BIOPLASGA: Bioplastic Elephant Grass Cellulose (Pennisetum Purpureum) With the Addition of Chitosan and Castor Oil for Plasticizers. Research students in this Student Research Creativity Program are Hestiana (Science Education), Mahclisatul Qolbiyah, Yashinta Devi (Chemistry) with a supervisor Dr. Eli Rohaeti, M.Sc. Hastiana explained that so far elephant grass has only been used as cattle feed, sometimes even only considered as a nuisance crop. contains 32.4% cellulose and 12.6% lignin. The high cellulose content and the relatively low lignin make elephant grass potential as a bioplastic feedstock. Meanwhile, more than one million plastic bags are used every minute, and 50% of them are only disposable. The more people use plastic, the more environmental pollution will increase. Therefore, biodegradable plastic materials (bioplastics) were developed. This type of plastic can decompose naturally into environmentally friendly compounds.

"That's what made us do this research. The research procedure we carried out, namely the synthesis of bioplastic cellulose of elephant grass is done by drying and smoothing the elephant grass and then cellulose is isolated by delignification. The results of cellulose isolation were added with chitosan (1%, 2%, 3%, 4%, 5%) and castor oil. Then poured into a mold and dried. Furthermore, the characteristics include functional groups, surface morphology, crystallinity, mechanical properties and biodegradation characteristics of bioplastics ", explained Hestiana.

Based on research conducted, he continued, the results of cellulose isolation are white, odorless and in the form of powder. As for the results of bioplastic synthesis in samples of 1%, 2%, 3%, 4% and 5%, they are brown, sharp-smelling, and have a smoother surface texture than the lower surface. Whereas 0% chitosan sample is not formed sheet but only like oily gel so that only functional groups can be tested.

In 1% samples, the sheet form is more fragile. In the functional group analysis, the peak O-H region in chitosan samples is 0% wider than bioplastic samples with chitosan concentrations of 1%, 2%, 3%, 4%, and 5%. This is because with the addition of chitosan, the O-H group is bound to the N-H group in the chitosan. The chitosan 2% sample has the sharpest absorption peak. Another difference was seen in the glycosidic CO absorption area, where the chitosan sample 0% only occurred 1 peak while in the sample chitosan concentration 1%, 2%, 3%, 4%, and 5% occurred 2 peaks, this showed the deformation of cellulose after added with chitosan.

In the analysis of mechanical properties, 4% chitosan bioplastic samples have the greatest tensile strength, elongation and Young's modulus, 0.8347 MPa, 7.4176% and 11.2529 MPa. The greater the concentration of chitosan, the greater the mechanical properties. However, this increase will be valid as long as polymer chain interactions are formed. In the analysis of the nature of biodegradation, the highest percent and mass loss rate was in the chitosan 1% bioplastic sample, namely 24.33% and 0.015 g / day. The greater the concentration of chitosan, the more difficult bioplastics are degraded because chitosan is antimicrobacterial.
"From the mechanical analysis test the results are 4% chitosan bioplastic samples which are the best results," he added.