The Rates of Crystallization of Copolyamides

Abstract

A group of polymers and copolymers based upon polyhexamethylene
adipamide (66 nylon) have been prepared. The comonomer ingredients
included 6-amino hexoic acid (for 6 nylon) , the salt of terephthalic
acid with hexamethylene diamine (for 6T nylon) ,and a blend of
trimesic acid with the diamine acting as a branching agent. The
polymeric materials were characterised by solution viscometry.

Apparatus for studying the rates of crystallization of polymers
and the published information for polyamides and copolymers is reviewed.
The construction of a hot stage attachment for a polarising
microscope is described, and the results from this equipment of the
crystallization rates and melting behaviour of the copolyamides are
reported. The results can be grouped into three series; 1. copolymerisation
of 66 nylon with 6 nylon resulted in a loss of crystallinity
together with a reduction in the melting temperatures and the temperatures
for observing crystallization behaviour; 2, copolymerisation
with 6T nylon resulted in a moderate retention of crystallinity due
to isomorphous crystallization; and 3, copolymerisation with a
branching agent resulted in both a loss of crystallinity and deviation
from the normal kinetic behaviour of polymer crystallization.

Observations on the melting of materials showed that the microscopy
technique is complementary with differential thermal analysis.
Some of the theories of the melting of polymers and copolymers have
been introduced in an attempt to explain the experimental data. Quantitative
measurements of the heats of fusion and densities of the
copolymers are reported.

Date of Award	1970
Original language	English