Novel green composites using zein as matrix and jute fibers as reinforcement

We demonstrate that zein-jute fiber composites developed using water plasticized zein as matrix can have substantially higher flexural and tensile properties than composites obtained using polypropylene as matrix. Zein is a plant protein that has been used to develop various types of thermoplastic products. Zein can be extracted from corn distillers dried grains (DDG) with potentially much lower cost than biopolymers in current use. However, thermoplastics developed from zein are brittle and it is necessary to use plasticizers or chemically modify zein to obtain useful zein-based products. Hydrophilic plasticizers such as glycerol that are retained in the composite after fabrication absorb moisture and considerably decrease the properties of the composites. Similarly, chemical modifications make the matrix materials expensive and/or decrease their biodegradability. In this research, we have used water to plasticize zein composites reinforced with jute fibers. Unlike plasticizers such as glycerol, water used as a plasticizer in this research evaporates during composite formation and does not affect the properties of the composites. Zein-jute composites have about 100% higher flexural strength, 82% higher tensile strength than similar PP-jute composites. The zein-jute composites have better flexural and tensile properties than PP-jute composites even at 21 °C and 90% relative humidity. Water serves as an effective plasticizer to utilize zein as a matrix for composites.

► Green composites without using any petro-based chemicals.
► Using water to plasticize zein composites reinforced with jute fibers.
► Zein composites have better flexural properties than polypropylene composites.
► Zein composites have better tensile properties than polypropylene composites.