Making a Supertough Flame-Retardant Polylactide Composite through Reactive Blending with Ethylene-Acrylic Ester-Glycidyl Methacrylate Terpolymer and Addition of Aluminum Hypophosphite

Abstract

Biocompatible and biodegradable polylactide (PLA) composites with supertough mechanical property and sufficient flame retardancy were fabricated by employing a facile approach involving reactive blending of PLA and ethylene-acrylic ester-glycidyl methacrylate terpolymer (EGMA), with the addition of aluminum hypophosphite (AHP) as an effective flame retardant. In consideration of the balance between mechanical property and flame retardancy, the optimal formula was taking a PLA/EGMA 80/20 blend (supertough STPLA) as the matrix and adding 20 wt % of AHP (relative to the mass of STPLA) as the flame retardant, coded as STPLA/20AHP. The mechanical property test showed that for STPLA/20AHP the elongation at break was increased by about 22 times and the notched Izod impact strength was enhanced by approximately 11 times as compared to those for neat PLA. The flame-retardant property test showed that for STPLA/20AHP the limiting oxygen index value reached 26.6% and the UL-94 V0 rating test was passed. Thermogravimetric analysis, microscale combustion calorimetry, and cone calorimeter were further applied to reveal the thermal stability and combustion behaviors of STPLA/ x AHP, respectively, where x indicated the mass content of AHP in percentage. The phase separation morphology, dispersion of AHP particles in STPLA matrix, and fracture surfaces and char residues after flame burning were examined by phase contrast optical microscopy and scanning electron microscopy, respectively, which helped comprehend the results obtained from the mechanical property and flame retardancy tests. The supertough STPLA/ x AHP, with sufficient flame retardancy as prepared in this work, could have a potential for engineering applications.

Rheological behavior and morphological and interfacial properties of PLA/TPE blends

“…The EE and EBG polymers have similar monomeric structures (ethylene chains); thus, their chemical affinity is higher than PLA–EBG. Li et al . reported that the T 5% temperature of PLA shifted from 351 to 360 °C after incorporating 20% ethylene–acrylic ester–glycidyl methacrylate (GMA) terpolymer in PLA.…”

Thermal Degradation and Fire Properties of Fungal Mycelium and Mycelium - Biomass Composite Materials

“…In addition to pure mycelium, the fire reaction properties of composites made from mycelium and wheat grain were measured experimentally using a cone calorimeter at an incident heat flux of 50 kW/m 2 , with temperatures ranging from 600 to 700 °C 38 – 40 . The composites were grown for 6, 12 and 18 d to ascertain the differences, if any, in their fire reaction properties associated with growth time.…”

Advances in Flame Retardant Poly(Lactic Acid)

“…Recently, mechanically tough FR PLA was reported by reactive blending of PLA with ethylene-acrylic ester-glycidyl methacrylate terpolymer (EGMA), with the addition of 20 wt % aluminum hypophosphite (AHP) as an effective flame retardant [43]. The matrix achieved a V-0 rating with an LOI of 26.6% and an appreciable reduction in peak heat release with an increase in the elongation at break by 22%.…”