Abstract
The addition of intumescent flame retardant to PLA can greatly improve the flame retardancy of the material and inhibit the dripping, but the major drawback is the adverse impact of the mechanical properties of the material. In this study, we found that the flame retardant and mechanical properties of the materials can be improved simultaneously by constructing a cross-linked structure. Firstly, a cross-linking flame-retardant PLA structure was designed by adding 0.9 wt% DCP and 0.3 wt% TAIC. After that, different characterization methods including torque, melt flow rate, molecular weight and gel content were used to clarify the formation of crosslinking structures. Results showed that the torque of 0.9DCP/0.3TAIC/FRPLA increased by 307% and the melt flow rate decreased by 77.8%. The gel content of 0.9DCP/0.3TAIC/FRPLA was 30.8%, indicating the formation of cross-linked structures. Then, the mechanical properties and flame retardant performance were studied. Results showed that, compared with FRPLA, the tensile strength, elongation at break and impact strength of 0.9DCP/0.3TAIC/FRPLA increased by 34.8%, 82.6% and 42.9%, respectively. The flame retardancy test results showed that 0.9DCP/0.3TAIC/FRPLA had a very high LOI (the limiting oxygen index) value of 39.2% and passed the UL94 V-0 level without dripping. Finally, the crosslinking reaction mechanism, flame retardant mechanism and the reasons for the improvement of mechanical properties were studied and described.
Highlights
With the growing awareness of sustainability in public perception, and more regulations restricting the materials being used in various of applications, biodegradable materials have become the focus in many fields [1,2,3,4]
The results showed that the limiting oxygen index (LOI) of the PLA composites with 3% methacrylic acid (MA)-microcrystalline cellulose (MCC) and 7%
The addition of 0.3 wt% TAIC made the Mn of 0.3TAIC/FRPLA increased by 39.6% (49,100 g/mol), which meant that TAIC can increase the molecular weight of PLA and promoted the formation of long chain structure of PLA
Summary
With the growing awareness of sustainability in public perception, and more regulations restricting the materials being used in various of applications, biodegradable materials have become the focus in many fields [1,2,3,4]. Results showed that the tensile strength and elongation at break of PLA composites containing only 5% BSI-APP were still better than the pure PLA with the UL94 V-0 level and LOI value of 26.7%. The results showed that the mechanical properties of flame-retardant PLA materials were similar to that of Polymers 2022, 14, 308 pure PLA samples by adding only 0.1 wt% TGIC. Different proportions of DCP and TAIC were used to determine whether they have synergy effect and the best proportion of them in flame-retardant PLA composites (the data were shown in the abbreviations). A small amount of DCP and TAIC (less than 1.5 wt%) with a specific proportion, which exert PLA with the best comprehensive performance, was selected to form a cross-linking structure in the flame-retardant PLA. The synergistic effect mechanism between DCP and TAIC was further studied
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
