Crystallization and thermal properties

This chapter is part of a recent book describing the synthesis, properties, and processing methods of poly(lactic acid) (PLA), an important family of degradable plastics. All the chapters have been written and reviewed from a base of international expert contributors. Chapter 9 devoted to the Crystallization and Thermal Properties of polylactic acid summarizes not only literature survey on the topic, but also the more than twenty years activity of our lab. PLLA, PDLLA and various copolymer are compared in terms of Tg, Tm, crystallinity and crystallizability, in dependence on molecular weight and processing conditions. Dynamical mechanical thermal analysis evidenced the effect of composition and crystallinity on storage modulus and damping factor. Crystallization regimes and the results of Avrami equation are reported. Some other original and unpublished data are also described, in particular related to the thermal properties of drawn and undrawn fiber produced from solution spinning. Hydrolytic degradation is properly commented in view of the applications. Index of Chapter 9. 9.1 Introduction 113 9.2 Crystallinity and Crystallization 114 9.3 Crystallization Regime 118 9.4 Fibers 119 9.5 Hydrolytic Degradation 121 References 123