The study of molecular weight and rate of change of molecular weight during thermal degradation of PLA suggests the random nature of chain scission with activation energy of 28 kcal/mol. The rate of weight loss indicates the formation of the volatiles by chain end initiation. The melting temperature of the polymer initially decreases and afterwards increases with increase in time of heating due to chain stiffening.
Polylactic acid have been prepared by solution polymerization of lactic acid. The TG, DTA and isothermal TG studies indicate, 1st order decomposition process with activation energy 22-25 kcal/mole in air.
Polysalicylide, a condensation product of acetylsalicylic acid, was irradiated with 60Co‐γ‐rays. Viscosity, end‐group analysis, and ultraviolet (UV) spectral measurement technique, and electrical conductivity were used to study the changes that occurred during γ‐radiolysis. It was observed that polysalicylide undergoes chain scission caused by weak links. The enthalpy of fusion is 16.0 and 13.4KJ/mol−1 repeat units of polysalicylide in air and N2, respectively. The indirect effective band gap decreased and electrical conductivity increased after irradiation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.