Side-Chain Crystallization in Alkyl-Substituted Semiflexible Polymers

A series of comblike semiflexible polymers, in which the alkyl side chains were located nonsymmetrically on the ring, were synthesized by reacting hydroxypropylcellulose (HPC) with hexyl, octyl, dodecyl, and octadecyl isocyanates. Side-chain melting was observed in DSC experiments for polymers with...

Full description

Saved in:
Bibliographic Details
Published in:Macromolecules 1997-11, Vol.30 (22), p.6877-6883
Main Authors: Lee, J. L, Pearce, E. M, Kwei, T. K
Format: Article
Language:English
Subjects:
Applied sciences
Cellulose and derivatives
Exact sciences and technology
Natural polymers
Physicochemistry of polymers
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A series of comblike semiflexible polymers, in which the alkyl side chains were located nonsymmetrically on the ring, were synthesized by reacting hydroxypropylcellulose (HPC) with hexyl, octyl, dodecyl, and octadecyl isocyanates. Side-chain melting was observed in DSC experiments for polymers with 12 and 18 carbons in the pendant groups (C12HPC and C18HPC). Wide-angle X-ray (WAXS) studies indicated that the alkyl groups in C12HPC crystallized in a form similar to the βT crystal of hydrocarbons but multiple crystalline forms coexisted in C18HPC. However, reorganization of the alkyl side chains was observed as the polymers underwent thermal transitions. A better packing of the alkyl side chains could be induced by shearing the samples in the molten state followed immediately by slow cooling. Quenching and annealing studies suggested that side-chain crystallization and reorganization could influence the packing of the semiflexible backbone. The interplay between the main chain and the side chain in order development is described.
ISSN:0024-9297
1520-5835
DOI:10.1021/ma970404k