# Selected Properties of a TPS/PA12 Composite Material Produced in a Two-Stage Method

## TL;DR

Researchers created a composite material using polyamide and starch, finding that up to 70% starch can be used without severely compromising mechanical properties.

## Contribution

A two-stage method was used to increase starch content in polymer composites to 70% while maintaining acceptable mechanical performance.

## Key findings

- Increasing starch content increased water susceptibility and reduced strength properties.
- 70% starch composite showed satisfactory mechanical properties.
- Negative effects of high starch content were less severe than expected.

## Abstract

The world economy is struggling with the increasing pollution of the natural environment with non-biodegradable synthetic polymers produced from petroleum products. This fact has prompted research on the use of natural renewable polymers. Starch is one of the polymers that has already been used as an additive to synthetic polymers; however, its use is associated with a problem arising from the incompatibility of hydrophilic starch with hydrophobic synthetic polymers. For these reasons, other authors have not used more than 20% of the starch component in synthetic materials. In this work, a research hypothesis was put forward that the starch content can be increased in the polymer material. Pre-extrusion was used before the final material molding process. Pre-extrusion improved the phase dispersion of the synthetic polymer blended with starch. To produce the molds, the polyamide and starch blends were subjected to the processes of extrusion, milling, and pressing. The molded samples containing polyamide and starch were obtained with a starch component content of 50, 70, and 90%. The obtained homogeneous material was determined in terms of its water resistance and mechanical properties. The test results showed that increasing the starch content in the produced material, increased its susceptibility to water, and worsened its strength properties. However, these negative effects were not as large as expected, and in some cases were even statistically insignificant. The addition of 70% of the starch component allowed for the production of a composite material with satisfactory mechanical properties.