The preparation of fully bio‐based flame retardant poly(lactic acid) composites containing casein

Abstract

In this work, a bio‐based flame retardant, casein, was incorporated into poly(lactic acid) (PLA) matrix by melt compounding in order to improve the fire resistance and sustain the biodegradable character of PLA simultaneously. The fire performance of PLA composites was evaluated by limiting oxygen index, UL‐94 vertical burning, and cone calorimeter tests, respectively. The results indicated that the introduction of 20% casein increased the limiting oxygen index value of PLA composites from 20.0% to 32.2%, upgraded the UL‐94 rating from no rating to V‐0, and decreased the peak heat release rate from 779 to 639 kW/m2. The decomposition products of PLA composites were analyzed by Fourier transform infrared, and the morphology of the char after combustion was observed by scanning electron microscopy. It was suggested that casein took effects in both gas phase by releasing non‐flammable gases (such as NH3 and H2O) and condensed phase by the formation of protective char layers. However, the presence of casein in PLA induced an unavoidable deterioration in the mechanical performance. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46599.

Synthesis of Novel Polymeric Acrylate-Based Flame Retardants Containing Two Phosphorus Groups in Different Chemical Environments and Their Influence on the Flammability of Poly (Lactic Acid)

“…The PLA composites achieved a UL94 V-0 rating upon addition of 20-30 wt.% of one of these biomass derived compounds. [20][21][22][23][24][25] Xuan et al synthesized melamine salts of bicyclic pentaerythritol phosphate alcohol (IFR-I and IFR-II). The incorporation of the new compounds in PLA improved the flame retardancy, reaching a V-0 classification with 20 wt.% addition in the best case.…”

Biomolecules as Flame Retardant Additives for Polymers: A Review

“…They were not as marked as the PET-only fabrics'-but exhibited no dripping, as the PET did; see Table 2. Casein has also been shown to be an effective flame retardant when incorporated into poly(lactic acid) [42]. blends at 20 wt % loadings.…”

“…They were not as marked as the PET-only fabrics'-but exhibited no dripping, as the PET did; see Table 2. Casein has also been shown to be an effective flame retardant when incorporated into poly(lactic acid) [42]. Gelatins, derived from bovine or fish sources, have been shown to reduce flammability in some polymer systems, including poly(vinyl alcohol) and polyolefins [43,44].…”

Effect of phosphorus–nitrogen compound on flame retardancy and mechanical properties of polylactic acid

“…However, most of the existing flame retardants are made from petroleum‐based materials, and developing biobased materials is helpful to increase the recyclability of PLA. Some biomacromolecules can be directly used as flame retardants of PLA, for example chitosan (CS), casein, lignin, and deoxyribose nucleic acid (DNA) 24–27 . Chen et al 24 added CS and ammonium polyphosphate (APP) into PLA directly.…”

“…The results showed that 2 wt% CS and 5 wt% APP can make PLA achieve the UL‐94 V‐0 rating with an increased LOI of 33.1%. Zhang et al 25 used casein to modify PLA. It was found that 20 wt% casein could increase the LOI of PLA composite from 20.0 to 32.2% and achieve the UL‐94 V‐0 rating.…”