Poly(lactic acid) plasticized by biodegradable glyceryl lactate

Abstract

The esterification of glycerol with lactic acid was carried out to synthesize glyceryl lactate, which was used as a as a plasticizer with different contents and blended with poly(lactic acid) (PLA) to get a completely biodegradable material with potential applications because of its biodegradability. The structural, morphological, thermal, and mechanical properties of the plasticized PLA were studied to evaluate the plasticizing effects. The results show that the PLA plasticized with glyceryl lactate had a lower glass-transition temperature and a better ductility. With increasing plasticizer content, the crystallinity of PLA increased. The elongation at break reached 380%, and the impact strength was 1.7 times that of neat PLA. Simultaneously, the migration rate measurements showed that glyceryl lactate presented relatively low migration toward the surface compared with glycerol and citrate esters. V C 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43460.

Synergistic effects of bio‐plasticizer and core–shell rubber on poly(lactic acid) toughness for sustainable flexible packaging applications

“…At higher temperature, the molecular interactions between PLA chains and TBR were weakened which allowed TBR to migrate easier. 21 Moreover, the migration of TBR also increased as its contents increased at the same times for all temperatures studied. In comparison, the amount of plasticizer migration observed in the current paper was lower than that observed in other plasticized PLA and PLA/PHA blends such as glyceryl lactate 21 and ester of citric acid.…”

Preparation and characterization of the plasticized polylactic acid films produced by the solvent‐casting method for food packaging applications

“…The presence of plasticizers in the PLA-based films is a usual method that is often used to enhance the flexibility, extensibility, and processability of PLA by increasing the mobility of polymer chains (Darie-Niţă et al, 2016;Fadl & Madkour, 2019;. However, due to their high mobility and low molecular weight, plasticizers can migrate to the matrix surface and contaminate materials in direct contact with plasticized PLA (Hassouna et al, 2012;Ljungberg & Wesslen, 2002;Yuan et al, 2016). Therefore, the selection of appropriate plasticizers with low volatility and moderate molecular weight in proper amounts is essential for food packaging application (Hassouna et al, 2011;Ljungberg & Wesslen, 2003;Murariu et al, 2008).…”

“…Plasticizing agents such as oligomeric lactic acid (OLA) (Burgos et al, 2013;Luzi et al, 2019), glycerol (Risyon et al, 2016), polyethylene glycol (PEG) (Arrieta et al, 2014;Courgneau et al, 2011), tributyl citrate (TBC) (Ljungberg & Wesslen, 2003;Yang et al, 2018), acetyltributyl citrate (ATBC) Arrieta et al, 2014), triethyl citrate (TEC) (Arrieta, de Dicastillo, et al, 2018), acetyltriethyl citrate (ATEC) (Shirai et al, 2013), and triacetin (TA) (Fadl & Madkour, 2019;Grigale-Soročina et al, 2010; are often mentioned as effective plasticizers for PLA plasticization. It has been reported that plasticizers have effectively increased elongation of PLA by facilitating its chains mobility and reducing interaction forces (hydrogen bonds) in the polymer matrix (Darie-Niţă et al, 2016;Yuan et al, 2016). However, as the concentration of plasticizer increases, the water permeability of the PLA films increases due to the high physisorption affinity of water molecules to PLA.…”

Thermal behaviors and characteristics of polylactide/poly(butylene succinate) blend films via reactive compatibilization and plasticization

“…To overcome these limitations and extend the possibility of more widespread usage, the flexibility and toughness of PLA can be improved by modifying its brittleness. The problem of enhancing the ductile properties of PLA in impact toughness and elongation at break while maintaining its biodegradability is approached in 3 main ways: physical blending with other flexible polymers, plasticization, and copolymerization with other monomers . Polylactide copolymerization is effective, but the technique is complicated, the cost relatively high, and industrial scale‐up difficult .…”