MSU Technologies

Polylactide Lignin Blends

Executive Summary

Increasingly, bio-sourced and biodegradable materials are being sought to replace petroleum or gas based polymers. Polylactic acid (PLA) is a well known biodegradable polymer that is used in a range of applications from biomedical devices to packaging materials. However, PLA by itself suffers from some deficiencies in mechanical properties. Lignin, is an abundant organic polymer found in plant cell walls such as wood and bark, but it’s commercial use is limited. MSU researchers have developed a novel process for preparing composites based on blends of PLA reinforced with modified lignins. The lignin stiffens the PLA based composite and increases it’s heat deflection temperature.

Description of Technology

This technology is method of making a polylactide lignin blend. The process involves first butyrating the lignin with butyric anhydride, then mixing with heated PLA to prepare the blended material. Either alkali or organosolve lignins can be used at up to 40 wt% of the blend. The resulting dried bio-composite material has good mechanical properties, whereby the lignin acts as fibers embedded in the PLA matrix.

Benefits

Uses bio-sourced and biodegradable material
Improved heat distortion temperatures over pure PLA
Increasing level of lignin stiffens material. Minor changes in mechanical properties with up to 10 wt% lignin.

Applications