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Development of biocomposites is becoming a necessity due to environmental concerns. Polylactide is a matrix of choice, regarding its bio‐sourced and compostable nature along with its mechanical properties. In this study, poly(L‐lactide)/flax biocomposites were produced using thermoplastic resin transfer molding (TP‐RTM) in one step process from the monomer, affording sustainable and fully compostable composite materials. The polymerization of L‐lactide (L‐LA) monomer was promoted by tin octoate, affording poly(L‐lactide) (PLLA) matrices displaying monomer conversions superior to 96% and mass‐average molar masses above 140,000 g/mol. Flax fibers were used as received without any functionalization which is usually conducted to prevent the hydroxyl groups to conduct side reactions. Mechanical testing revealed bending modulus of 9.3 GPa and bending strength of 177 MPa comparable to existing literature values for PLLA/flax composites produced by other techniques. Digital microscopy analysis provided insights into impregnation quality and void characterization within the composites. In addition, the durability of these biocomposites was also evaluated via accelerated aging tests. Highlights: PLLA/flax biocomposites were produced by TP‐RTM for the first time.In situ polymerization of the PLLA matrix associated with non‐functionalized flax fabrics was conducted.Bending properties were found in line with those of PLLA/flax composites produced by compression molding.Aging tests under UV at 50°C of PLLA/flax biocomposites were conducted. [ABSTRACT FROM AUTHOR]

This study applies the Morris method for a sensitivity analysis to evaluate the input parameters' influence on the heat release rate in a pyrolysis model, focusing on two materials, poly(methyl methacrylate) (non-charring) and poly(vinyl chloride) (charring), examined under a cone calorimeter. A key aspect of our exploration was the role of input parameter variation intervals on the sensitivity outcomes. We analyzed three interval-setting methods: 1. A standard ±10% deviation from the nominal value, commonly used in the literature. 2. A range determined by the experimental uncertainties for individual parameters. 3. A span from minimum to maximum values found in existing literature for each parameter. Our intensive literature review supported the framing of intervals for the latter two methods. Our findings underscore the critical role of the selected variation interval. Specifically, while a uniform ±10% variation identified activation energies as the primary influencers—consistent with prior literature—the introduction of experimental uncertainties shifted this prominence toward heats of reaction. Thus, the selected interval can drastically reshape the perceived importance of certain parameters. This original work challenges the traditionally employed variation ranges in sensitivity studies, emphasizing the need for a nuanced approach. [ABSTRACT FROM AUTHOR]

The mixture of ammonium polyphosphate and pentaerythritol is a very efficient intumescent system suitable for polyolefins, especially polypropylene. In this article, the intumescence mechanism of this intumescent system with and without zeolite 4A used as a synergy agent is revisited. The intumescent system was investigated in depth using continuous-wave electron paramagnetic resonance spectroscopy, solid-state nuclear magnetic resonance, and the advanced technique, namely hyperfine sublevel correlation pulsed electron paramagnetic resonance. It was observed that the char generated between 250°C and 350°C is made of polycyclic heterocyclic radicals with nitrogen atoms and that free radicals are mainly generated at these temperatures with a spin concentration relatively stable at least up to 500°C. Moreover, the presence of hydrogen, carbon, nitrogen, and phosphorus was clearly evidenced in the chemical environment of free electrons at 350°C (hyperfine sublevel correlation pulsed electron paramagnetic resonance). Besides, it was also evidenced that 4A totally collapses below 250°C. Contrary to previous works suggesting the presence of aluminosilicophosphate complexes, this work demonstrated that distinct alumino- and silicophosphate complexes are generated and protected the residue at high temperatures. [ABSTRACT FROM AUTHOR]

An intumescent‐flame‐retardant vinyl acetate–ethylene copolymer (IFR/VAE) compound has been prepared by blending with a complex of melamine amino trimethyl phosphate (M‐AT) and sodium lignosulfonate (SL). Then, this obtained IFR/VAE polymer was applied as adhesives for producing the flame‐retardant plywood. The IFR VAE sample (VAE/M‐AT3/SL1) with a mass ratio 3:1 (M‐AT to SL) showed an enhanced amount of char residue, limiting oxygen index (LOI) value and tensile strength value to 20.6 wt%, 32 vol% and 19.3 MPa, which have been increased by 796%, 600%, and 56% compared to that of neat VAE. The cone calorimeter result showed that the peak of heat release rate (pHRR) of VAE/M‐AT3/SL1 sample was reduced by 48% compared to the control one. Additionally, the second peak of HRR of sample IFRPW/15 L/15 (containing 15 wt% M‐AT3/SL1 in the plywood adhesive layer) presented a reduction of 29% compared to that of the sample PW/15 L (neat plywood). It is assigned to the formation of phospho‐carbonaceous structure during combustion, thus the flame‐retardancy of plywood has been greatly enhanced. Thus, this work provides an economical and applicable fire‐retardant VAE adhesive formula for producing plywood materials with good performances. [ABSTRACT FROM AUTHOR]