ISSN:
0887-624X
Schlagwort(e):
segmented copoly(ether-ester)s
;
hard segment
;
soft segment
;
random copolymers
;
thermotropic liquid crystalline polymers
;
mesophase
;
thermotropic elastomers
;
thermal properties
;
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Syntheses of segmented copoly(ether-ester)s with (oxy-2-methyl-1,4-phenyleneoxycarbonyl-1,4-phenylene carbonyl)/(oxy-2-chloro-1,4-phenyleneoxycarbonyl-1,4-phenylene carbonyl) (methyl-/chloro-substituted) hard segments and poly(oxytetramethylene) soft segments, are reported. The methodology consisted of staged addition melt condensation of terephthaloyl chloride, poly(oxytetramethylene)glycol (POTMG; \[ \bar M_n \] = 250, 650, 1000, 2000) and methyl-/chloro-hydroquinone. Lengths of hard and soft segments were varied while the weight ratio of hard to soft segment was maintained constant. Copolymers were characterised for solubility behavior, and by infrared spectroscopy, x-ray diffraction, DSC, and polarizing microscopy. Thermal properties were found to be dependent on length of soft segment as well as on the type of substituent in the mesogenic core. In both methyl- as well as chloro-substituted copoly(ether-ester)s soft segment glass transition temperature (Tgs) was obtained between -40 and -50°C. All copoly(ether-ester)s are elastomeric at room temperature (25°C). These polymers exhibit thermotropic liquid crystalline behavior and were easily sheared and aligned in liquid crystalline state. © 1994 John Wiley & Sons, Inc.
Zusätzliches Material:
9 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/pola.1994.080321601
Permalink
