Glycolic acid polymers temperature

All these plastics are essentially the same compound, composed of terephthalic acid (para-phthalic acid) esterified with ethylene glycol. This polyester is made by a base-catalyzed transesterification of dimethyl terephthalate with ethylene glycol at a temperature around 150 °C. At this temperature, methanol escapes as a gas, driving the reaction to completion. We will study polyesters and other polymers in more detail in Chapter 26. 

The same approach was applied to other biodegradable polymers as poly(beta-hydroxy-buthyric acid) (PHB), poly(caprolacton) (PCL), and poly(glycolic acid). In the last case, because of the high melting temperature of PGA at which PVA decomposes, the second blend component was PP and as a solvent for its removal xylene was used. The morphology of the scaffold materials of these polymers is demonstrated in Figure 17.20. 

As widely usable biodegradable materials, PLA is found to exhibit too hard and too brittle characters. The weakness might be improved when a polymer with lower glass transition temperature is used together [18]. Polyfe-caprolactone) (PCL) and poly(glycolic acid) (PGA), also known as polyglycolide, are two other... 

L. Yu, G. Chang, H. Zhang, J. Ding, Temperature-induced spontaneous sol-gel transitions of poly(D,E-lactic acid-co-glycolic acid)-b-poly(ethylene glycol)-b-poly(D,L-lactic acid-co-glycolic acid) triblock copolymers and their end-capped derivatives in water. Journal of Polymer Science, Part A Polymer Chemistry, 45,1122-33,2007. 

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