Packaging applications aliphatic polyesters

A controllable biodegradability, desirable mechanical properties, suitable gas permeability and selectivity would extend the potential application areas of aliphatic polyesters not only in agriculture or in the greenhouse or packaging industry but also as a substitute for human skin. There is a need for such focused studies in the future. 

However, compositions derived from PLA and aliphatic polyesters exhibit a high gas permeability. This is a drawback for packag-ing applications of food. 

PCL -OCH CH CH CH CH CO-ln) is a partially-crystalline polyester that is biodegraded by microbial lipases and esterases. The plastic is made from petrochemical feedstocks. It has too low a melting point (60°C) to be useful in any packaging applications. Higher aliphatic polyesters such as poly(butylene succinate) (PBS) (-0(CH2) OC(CH2)2CO-)n and poly(ethylene succinate) (PES) (-OCCH l OOCCCH l CO-) are also biodegradable at a rate that depends on environmental factors (Kasuya et al., 1997). They have higher melting points of 112-114°C and 103-106°C, respectively, and the properties compare well to those of polyolefins. As succinic acid can be derived from plant sources, the polysuccinates can be potentially a bio-based polymer. 

Polylactic acid (PLA), polyglycolate (PGA), poly(3-hydroxybutyrate), polyc-aprolactone (PCL), polyhydroxyvalerate (PHV) and their copolymers poly(butylene succinate) (PBSu), poly(ethylene succinate) (PESu), poly(propylene adipate) (PPAd), etc., are the most commonly used aliphatic polyesters for such applications as packaging materials, mulch Aims, tissue engineering, implants, drug delivery etc. 

Poly(e-caprolactone)/PLA Blends Poly( -caprolactone) (PCL) is a water-insoluble biodegradable, petroleum-based aliphatic polyester synthesized by ringopening polymerization of -caprolactone (e-CL) [81, 82]. PCL blends are widely used in many applications such as compostable bags for yard waste or other organics collection, disposable food service items, food packaging, health care products, mulch films in agriculture, and adhesives [81, 82, 101-103]. The nontoxicity, biocompatibility. 

Poly(L-lactide) (PLLA) is a biodegradable aliphatic polyester produced by ring-opening polymerization of lactide (i.e., with cyclic dimer of lactic acid) or by polycondensation of lactic acid. Although PLLA is a synthetic polymer, it is considered a renewable and bio-based plastic because its raw material lactic acid is synthesized from biomass or renewable resources such as sugars and starch. PLLA has some properties that are similar to some petroleum-based plastics, thereby making it suitable for a variety of applications in the medical, textile, and packaging industries. 

Aliphatic polyester (e. g., PLA, PGA, PCL) represent a very interesting class of plastics that decompose in contact with living organisms and thus can be utilized as biodegradable packaging materials, among other applications. 

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