Preliminary results on the synthesis and characterization of anisotropic networks, oriented on a macroscopic scale, are reported. Fiber samples of segmented thermotropic liq.-cryst. polymers bearing the oxypentenyl lateral substituent have been crosslinked via thermally activated radical reaction. This was made possible by immersion of fiber samples in dichloromethane contg. tert-Bu peroxybenzoate as activating agent, thus allowing its diffusion in the samples. Subsequent annealing at 145°C bring us to an anisotropic network with no loss of the original orientation. A mesophase is stabilized and no structural modification is obsd. by heating samples from room temp. up to 400°C, where thermal decompn. takes place. Cross-linked fibers exhibit good tensile properties, at both room temp. and at 150°C.
Crosslinking of a fibrous sample to a macro-oriented mesomorphic network
DI MAIO, Luciano;IANNELLI, Pio;PRAGLIOLA, Stefania;
1998-01-01
Abstract
Preliminary results on the synthesis and characterization of anisotropic networks, oriented on a macroscopic scale, are reported. Fiber samples of segmented thermotropic liq.-cryst. polymers bearing the oxypentenyl lateral substituent have been crosslinked via thermally activated radical reaction. This was made possible by immersion of fiber samples in dichloromethane contg. tert-Bu peroxybenzoate as activating agent, thus allowing its diffusion in the samples. Subsequent annealing at 145°C bring us to an anisotropic network with no loss of the original orientation. A mesophase is stabilized and no structural modification is obsd. by heating samples from room temp. up to 400°C, where thermal decompn. takes place. Cross-linked fibers exhibit good tensile properties, at both room temp. and at 150°C.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
