Number: 2004-044-2-400
Title: Microstructure and properties
of thermotropic liquid crystalline polymer blends and composites
Task Group
Chairman: Jiasong
He
Members: Seong
Hun Kim, Sung Chul
Kim, and more tba
Objective:
To evaluate the microstructure-property correlation of thermotropic
liquid crystalline polymer blends and composites
Description:
The synthesis and modification of thermotropic liquid crystalline
polymers (TLCP) for different final applications are currently hot
topics of industrial as well as academic research. The copolymerization
of different comonomers leads to polymers with different liquid
crystalline characteristics, melting temperatures, rheological behavior.
The incorporation of some comonomers is applied to reduce the processing
temperature but still keep the liquid crystalline characteristics.
TLCPs having different chemical structure are processed to different
end-use forms of products by injection molding, extrusion, stretching,
blowing and spinning. TLCPs are currently produced by Solvay, Eastman,
Ticona, Polyplastics, DuPont, Mitsubishi, Sumitomo, and Unitika,
and are commercialized as glass fiber-filled, glass beads-filled,
glass flakes-filled, silica-filled grades for injection-molded parts,
and tubes, films, bottles and fibers in IT, automobile, chemical,
medical and hi-tech industries. The microstructure of commercialized
TLCP blends and composites is closely related to their processing
conditions. The relation between the rheological properties and
the resultant microstructure of these blends and composites should
be well established. The aim of this research is to evaluate microstructure-property
relation of the commercialized TLCP blends and composites (e.g.
glass fiber-filled grades) by the rheological measurement (dynamic
and steady rheology), morphology observation (SEM, WAXD) and property
evaluation (mechanical tests).
Previous IUPAC project resulted in one paper is published in Pure
and Applied Chemistry, 76(11), 2027-2049 (2004), "Rheological
properties and associated structural characteristics of some aromatic
polycondensates including liquid-crystalline polyesters and cellulose
derivatives", J. L. White, L. Dong, P. Han and H.M. Laun.
This paper reports 4 different types of liquid crystalline polyesters
and 1 type of glass fiber-filled LCP.
In recent years, the rapid development of IT products leads to
an annual consumption growth of 25% for commercialized LCP blends
and composites. Different commercialized grades of LCP blends and
composites (with different fillers) are available for fabrication
of final products. It is of interest to have a new IUPAC project
to correlate the microstructure and rheological properties of filled
LCP blends and composites.
The study of this project will be focused on TLCP pellets as follows:
