Advances in Flame Retardant Poly(Lactic Acid)

Abstract

PLA has become a commodity polymer with wide applications in a number of fields. However, its high flammability with the tendency to flow in fire has limited its viability as a perfect replacement for the petrochemically-engineered plastics. Traditional flame retardants, which may be incorporated into PLA without severely degrading the mechanical properties, are the organo-halogen compounds. Meanwhile, these compounds tend to bioaccumulate and pose a risk to flora and fauna due to their restricted use. Research into PLA flame retardants has largely focused on organic and inorganic compounds for the past few years. Meanwhile, the renewed interest in the development of environmentally sustainable flame retardants (FRs) for PLA has increased significantly in a bid to maintain the integrity of the polymer. A review on the development of new flame retardants for PLA is presented herein. The focus is on metal oxides, phosphorus-based systems, 2D and 1D nanomaterials, hyperbranched polymers, and their combinations, which have been applied for flame retarding PLA are discussed. The paper also reviews briefly the correlation between FR loadings and efficiency for various FR systems, and their effects on processing and mechanical properties.

Design and Application of Highly Efficient Flame Retardants for Polycarbonate Combining the Advantages of Cyclotriphosphazene and Silicone Oil

“…To understand the flame-retardant effect of HSPCTP on PC, the TG-IR of pure PC and PC/HSPCTP3 were investigated, as shown in Figure 9. It is clear that both the curves of pure PC and PC/HSPCTP3 show characteristic bands of water (3650 cm −1 , 1259 cm −1 , O–H bond) [41,42], aliphatic compounds (2972 cm −1 , 1248 cm −1 , 748 cm −1 ) [31,43], carbon dioxide (2300–2400 cm −1 ) [31,43], compounds containing aromatic rings (1610 cm −1 , 1505 cm −1 ) [31,43] and nitrogen compounds (1200 cm −1 ) [41]. The characteristic bands of the two samples are similar.…”

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

“…Current works mainly focus on phosphorus, silicon, and nitrogen flame retardants 11–17 . Particularly, phosphorus are widely used in synergy with nitrogen due to their excellent efficiency 18–20 .…”

Flame retardant poly (lactic acid) biocomposites based on azo‐boron coupled 4,4′‐sulfonyldiphenol and its combination with calcium lignosulfonate—Crystalline and mechanical properties

“…To minimize the fire risk associated with the use of PLA and meet safety requirements for specific applications, solutions meant to delay, suppress, and prevent ignition and lower the peak heat release rate (PHRR) and total heat release (THR) during combustion have been developed . These solutions are in the form of intrinsic monomer modification of the base polymer during synthesis to the use of additives like minerals, halogenated compounds, phosphorus, and nitrogen‐containing compounds, silicon, and layered nanomaterials . Most of the FRs act mainly by interfering with the usual combustion cycle of the pristine polymer through physical or chemical action .…”

“…The last decade has witnessed significantly interesting researches geared towards obtaining bio‐based FR PLA with the quest to maintain its bio integrity. Notable FRs in this regard include graphene, nano‐clays, layered double hydroxides (LDHs), fullerene, carbon nanotubes and rods, cellulose, hemicellulose, starch, cyclodextrin, isosorbides, chitosan, lignin, deoxyribonucleic acid (DNA), phloroglucinol, proteins (casein, hydrophobins, whey protein), and vegetables oils . Among the bio‐based FRs, lignin possesses unique advantage as the most sustainable, inexpensive, naturally abundant polyaromatic polyol, commercially available as a byproduct of the papermaking industry .…”