The Effect of Glycerin Addition on the Tensile Strength and Density of Potato Starch Bioplastic.

Abstract

The use of conventional plastics that are not environmentally friendly encourages the development of bioplastics based on
natural materials. This study aims to determine the effect of the addition of glycerin as a plasticizer on the mechanical and
physical properties of bioplastics made from potato starch. The variation in the amount of glycerin used was 1%, 2%, and 3%,
then testing was carried out on the tensile strength and density of the specimen. The results showed that the increase in the
amount of glycerin in general increased the density of bioplastics from 2,084 gr/cm³ to 2,406 gr/cm³, as well as tensile strength
from 0.124 MPa to 0.408 MPa. The modulus of elasticity also increased significantly, from 32.12 GPa to 81.11 GPa.
Meanwhile, the strain value showed a non-linear pattern, decreasing at 2% but increasing again at 3%. The conclusion of this
study is that glycerin is effective as a plasticizer because it is able to increase the mechanical strength and rigidity of bioplastics,
as well as modify its flexibility depending on the amount used. This research supports the development of environmentally
friendly bioplastics based on renewable materials such as potato starch.