Breaking Ground in Flame Retardant PLA Composites Using Hydromagnesite & Huntite with Bio-Based Plasticizer

Transforming poly(lactic acid) (PLA) from a brittle state to a ductile form is a pivotal consideration in plastics engineering, especially when dealing with high additive concentrations. This study explores the creation of ductile green fire-retardant PLA composites by incorporating hydromagnesite & huntite (HH) as a natural fire retardant additive and acetyl tributyl citrate as a bio-based plasticizer.

The integration of these components aims to enhance the environmental friendliness of PLA composites, especially in applications demanding fire resistance. The plasticizer inclusion serves as a key element in making PLA more malleable, essential for processing with significant additive loads.

Test results revealed intriguing insights into the impact of plasticizer and HH concentrations on the fire retardant, thermal, and mechanical properties of the composites. Notably, the limiting oxygen index (LOI) and UL-94 V rating underwent changes, showcasing the influence of plasticizer content on melt viscosity and fire performance.

With a 20 wt% plasticizer addition, the LOI value decreased from 29.2 to 28.0, and the UL-94 V rating transitioned from V2 to BC. This reduction in LOI value was attributed to a viscosity decrease. Conversely, achieving ductile flame-retardant material necessitated a 20 wt% plasticizer content alongside 70 wt% HH, resulting in the highest LOI value of 36.2 and a V0 UL-94 rating.

The study also noted the trade-offs associated with plasticizer incorporation. While impact resistance improved, there was a reduction in tensile strength with increasing plasticizer content. This emphasizes the intricate balance required to achieve desired properties in flame-retardant PLA composites for specific applications in the plastics engineering domain.

You can read more about this topic in the article “Development of ductile green flame retardant poly(lactic acid) composites using hydromagnesite & huntite and bio-based plasticizer” by Ayşegül Erdem, Mehmet Dogan, published in the November 2023 issue of JVAT (Journal of Vinyl and Additive Technology 2023; 29:978–990), chosen as Editor’s Choice article for highlighting flame retardancy (UL-94 rating of V0) using commercially available cost-effective natural flame retardant filler in plasticized polylactic acid (PLA).