Hits:

Indexed by:期刊论文

Date of Publication:2017-06-01

Journal:EUROPEAN POLYMER JOURNAL

Included Journals:SCIE、EI

Volume:91

Page Number:376-385

ISSN No.:0014-3057

Key Words:Poly(lactic acid); Crystallization; Memory effect; FTIR

Abstract:The influence of crystalline memory effect on poly(lactic acid) (PLA) crystallization was probed by time-resolved Fourier transform infrared spectroscopy (FTIR). The melt with different degrees of order was prepared by melting at various temperatures. The vibrational changes associated with inter- and intra-chain interactions during crystallization were monitored. In the initial period of crystallization, the order of intensity changes is as follows: 1458 cm(-1) > 1210 cm(-1) >> 921 cm(-1), 1458 cm(-1) > 1210 cm(-1) > 921 cm(-1), and 1458 cm(-1) > 1210 cm(-1)- 921 cm(-1) for PLA melted at 190, 170, and 168 C, respectively. With increasing the degree of order, both the formation of skeletal conformational-ordered structure and, especially, the 103 helix structure are accelerated. The influence of memory effect on the crystallization kinetics was also discussed based on the Avrami model.