Effect of molecular weight on crystallization behavior of poly (lactic acid) under isotherm and non‐isotherm conditions

Author(s):  
Nader Zirak ◽  
Mohammadali Shirinbayan ◽  
Sedigheh Farzaneh ◽  
Abbas Tcharkhtchi
Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1822
Author(s):  
Evangelia Balla ◽  
Vasileios Daniilidis ◽  
Georgia Karlioti ◽  
Theocharis Kalamas ◽  
Myrika Stefanidou ◽  
...  

Environmental problems, such as global warming and plastic pollution have forced researchers to investigate alternatives for conventional plastics. Poly(lactic acid) (PLA), one of the well-known eco-friendly biodegradables and biobased polyesters, has been studied extensively and is considered to be a promising substitute to petroleum-based polymers. This review gives an inclusive overview of the current research of lactic acid and lactide dimer techniques along with the production of PLA from its monomers. Melt polycondensation as well as ring opening polymerization techniques are discussed, and the effect of various catalysts and polymerization conditions is thoroughly presented. Reaction mechanisms are also reviewed. However, due to the competitive decomposition reactions, in the most cases low or medium molecular weight (MW) of PLA, not exceeding 20,000–50,000 g/mol, are prepared. For this reason, additional procedures such as solid state polycondensation (SSP) and chain extension (CE) reaching MW ranging from 80,000 up to 250,000 g/mol are extensively investigated here. Lastly, numerous practical applications of PLA in various fields of industry, technical challenges and limitations of PLA use as well as its future perspectives are also reported in this review.


2018 ◽  
Author(s):  
Mujtahid Kaavessina ◽  
Sperisa Distantina ◽  
Achmad Chafidz ◽  
Aditya Utama ◽  
Venisa Mega Puteri Anggraeni

2008 ◽  
Vol 16 (9) ◽  
pp. 597-604 ◽  
Author(s):  
Wang Ning ◽  
Zhang Xingxiang ◽  
Yu Jiugao ◽  
Fang Jianming

Poly(lactic acid) (PLA) is a biodegradable thermoplastic that can be produced from renewable resources, and so was considered as a major alternative to petroleum-based plastics for packaging applications. However, plasticisation of PLA was required in order to obtain films with sufficient flexibility. Poly(1, 3-butylene adipate) (PBA) was used as a novel plasticiser for PLA, and acetyltributyl citrate (ATBC) was used as the control. FTIR revealed that interaction took place between PLA and plasticiser. With an increasing plasticiser content, storage modulus and glass transition temperature decreased, but elongation at break increased. The elongation at break of PBA-plasticised PLA (PBA content 30 wt.%) could be above 600%, higher than that of ATBC-plasticised PLA (ATBC content 30 wt.%). Moreover, PBA was able to restrain thermally induced migration of plasticiser in plasticised PLA. It was also found that the migration rate of ATBC was directly proportional to the ATBC content in the blends. The rheology showed that the plasticiser could obviously decrease the shear viscosity and improve the fluidity of the blends. PBA was therefore recognised as a novel plasticiser for enhancing the properties of PLA. In particular, as a biodegradable polymer, PBA, when used as a plasticiser in PLA, can enhance migration resistance for its proper molecular weight. Moreover, the area of application of plasticised PLA is broadened.


2019 ◽  
Vol 57 (7) ◽  
pp. 814-826 ◽  
Author(s):  
Pengfei Xie ◽  
Jiao Wang ◽  
Jianbo Li ◽  
Qian Cheng ◽  
Keyu Zhou ◽  
...  

Author(s):  
Érica da Cruz Faria ◽  
Marcos Lopes Dias ◽  
Luana Marques Ferreira ◽  
Maria Ines Bruno Tavares

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