Crystal nucleation and growth of natural rubber purified by deproteinization and trans-esterification

The crystallization of highly purified natural rubber (NR) was investigated by polarized light microscopy. NR was deproteinized with proteolytic enzyme in the presence of surfactant and further purified by acetone-extraction followed by transesterification to remove all mixed and linked fatty acids...

Full description

Saved in:
Bibliographic Details
Main Authors: Seiichi Kawahara, Keiko Takano, Jintana Yunyongwattanakorn, Yoshinobu Isono, Masamichi Hikosaka, Jitladda T. Sakdapipanich, Yasuyuki Tanaka
Other Authors: Nagaoka University of Technology
Format: Article
Published: 2018
Subjects:
Online Access:https://repository.li.mahidol.ac.th/handle/123456789/21430
Tags: Add Tag
No Tags, Be the first to tag this record!
Institution: Mahidol University
Description
Summary:The crystallization of highly purified natural rubber (NR) was investigated by polarized light microscopy. NR was deproteinized with proteolytic enzyme in the presence of surfactant and further purified by acetone-extraction followed by transesterification to remove all mixed and linked fatty acids present in NR. The rubber was fractionated and characterized by size exclusion chromatography,1H and13CNMR spectroscopy. Fractionated rubbers were crystallized at 252-258 K, in which spherulite was observed. The estimated nucleation and growth rates depended on supercooling. Surface free energies were determined for highly purified NR. Nucleating effect of fatty acids on the crystallization was proved by change in the surface free energy after removing and/or adding fatty acids.