Synthesis of Poly(D-Lactic Acid) Using a 2-Steps Direct Polycondensation Process

Pivsa‐Art, Sommai; Tong-ngok, Thikanda; Junngam, Supansa; Wongpajan, Rutchaneekorn; Pivsa‐Art, Weraporn

doi:10.1016/j.egypro.2013.06.791

Cited by 17 publications

(11 citation statements)

References 11 publications

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“…In other words, using prepolymer with lower initial molecular weight leads to higher PLA molecular weight after polycondensation reaction. This observation agrees well with the other work's findings .…”

Section: Resultssupporting

confidence: 94%

“…PLA synthesis through direct polycondensation of lactic acid is a simple and efficient way in which esterification process takes place in the molten state with the secondary alcohols and carboxylic end groups . However, insufficient heat and mass transfer in the course of polymerization caused by viscosity upturn together with considerable amount of side reactions, e.g., degradation reactions and lactide formation, facilitate chains scission and thereby decreases PLA molecular weight .…”

Section: Introductionmentioning

confidence: 99%

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A journey across the solid state polymerization to assess the role of critical factors influencing the molecular weight of polylactic acid

Davoodi

Ahmadi

Taromi

2018

Vinyl Additive Technology

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Solid state polymerization (SSP) offers an effective route for synthesizing green polymers with variable molecular weights depending on polymerization condition. In this work, critical factors governing the molecular weight of polylactic acid (PLA) in the course of SSP are manipulated systematically and their contributions to the efficiency of SSP process are discussed. The initial molecular weight of the prepolymer formed, the degree of crystallinity of prepolymer, and the SSP time are changed and analyzed for their effects through different analyses including differential scanning calorimetry, gel permeation chromatography, and Fourier‐transform infrared spectroscopy techniques. It was observed that PLA having highest molecular weight would be the result of formation of a prepolymer having low‐molecular weight, as detected by the analysis of functional group concentration. For the optimized sample, the rate of mass loss in SSP was 12,263 g/mol.day and a crystallinity drop over the hydrolysis process was 3.14 per day. The crystallinity of prepolymers was optimized at ca. 26% in regard with the PLA showing the highest molecular weight. J. VINYL ADDIT. TECHNOL., 25:165–171, 2019. © 2018 Society of Plastics Engineers

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Section: Resultssupporting

confidence: 94%

Section: Introductionmentioning

confidence: 99%

A journey across the solid state polymerization to assess the role of critical factors influencing the molecular weight of polylactic acid

Davoodi

Ahmadi

Taromi

2018

Vinyl Additive Technology

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“…A large number of patents and articles about lactic acid polymers have been published in recent years (Jompang et al 2013;Padee et al 2013;Pivsa-Art et al 2013;Li et al 2014;Shi et al 2015). Although demand for PLA has expanded, its current production capacity of 450 million kg per year is dwarfed by the 200 billion kg of total plastics produced per year.…”

Section: Applicationsmentioning

confidence: 99%

Lactic Acid Production to Purification: A Review

Komesu

Oliveira

Martins

et al. 2017

BioRes

207

114

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Lactic acid is a naturally occurring organic acid that can be used in a wide variety of industries, such as the cosmetic, pharmaceutical, chemical, food, and, most recently, the medical industries. It can be made by the fermentation of sugars obtained from renewable resources, which means that it is an eco-friendly product that has attracted a lot of attention in recent years. In 2010, the U.S. Department of Energy issued a report that listed lactic acid as a potential building block for the future. Bearing the importance of lactic acid in mind, this review summarizes information about lactic acid properties and applications, as well as its production and purification processes.

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“…A pre-polymer product was formed first, using p-toluene sulfonic acid without the addition of any catalyst. This product was then subjected to solid-state polymerization under high temperature and pressure conditions [89].…”

Section: Strategies For Designing Polymeric Nanoparticlesmentioning

confidence: 99%

Polymeric Nanoparticles in Gene Therapy: New Avenues of Design and Optimization for Delivery Applications

2019

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The field of polymeric nanoparticles is quickly expanding and playing a pivotal role in a wide spectrum of areas ranging from electronics, photonics, conducting materials, and sensors to medicine, pollution control, and environmental technology. Among the applications of polymers in medicine, gene therapy has emerged as one of the most advanced, with the capability to tackle disorders from the modern era. However, there are several barriers associated with the delivery of genes in the living system that need to be mitigated by polymer engineering. One of the most crucial challenges is the effectiveness of the delivery vehicle or vector. In last few decades, non-viral delivery systems have gained attention because of their low toxicity, potential for targeted delivery, long-term stability, lack of immunogenicity, and relatively low production cost. In 1987, Felgner et al. used the cationic lipid based non-viral gene delivery system for the very first time. This breakthrough opened the opportunity for other non-viral vectors, such as polymers. Cationic polymers have emerged as promising candidates for non-viral gene delivery systems because of their facile synthesis and flexible properties. These polymers can be conjugated with genetic material via electrostatic attraction at physiological pH, thereby facilitating gene delivery. Many factors influence the gene transfection efficiency of cationic polymers, including their structure, molecular weight, and surface charge. Outstanding representatives of polymers that have emerged over the last decade to be used in gene therapy are synthetic polymers such as poly(l-lysine), poly(l-ornithine), linear and branched polyethyleneimine, diethylaminoethyl-dextran, poly(amidoamine) dendrimers, and poly(dimethylaminoethyl methacrylate). Natural polymers, such as chitosan, dextran, gelatin, pullulan, and synthetic analogs, with sophisticated features like guanidinylated bio-reducible polymers were also explored. This review outlines the introduction of polymers in medicine, discusses the methods of polymer synthesis, addressing top down and bottom up techniques. Evaluation of functionalization strategies for therapeutic and formulation stability are also highlighted. The overview of the properties, challenges, and functionalization approaches and, finally, the applications of the polymeric delivery systems in gene therapy marks this review as a unique one-stop summary of developments in this field.

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Synthesis of Poly(D-Lactic Acid) Using a 2-Steps Direct Polycondensation Process

Cited by 17 publications

References 11 publications

A journey across the solid state polymerization to assess the role of critical factors influencing the molecular weight of polylactic acid

A journey across the solid state polymerization to assess the role of critical factors influencing the molecular weight of polylactic acid

Lactic Acid Production to Purification: A Review

Polymeric Nanoparticles in Gene Therapy: New Avenues of Design and Optimization for Delivery Applications

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