A series of new chiral side chain liquid crystalline copolymers was prepared from (S)4-(5-acryloyloxy-4-methylpentanoyloxy)-4'-octyloxybiphenyl having a chiral center in a flexible spacer and 4-hexyloxyphenyl 4-(6-acryloyloxyhexyloxy) benzoate. They were characterized by DSC, polarizing optical microscopy, piezoelectric technique and X-ray diffraction. The copolymers were shown to exhibit a rich chiral smectic phase polymorphism. A variety of smectic modifications increases with increasing number of achiral monomer units. The copolymer of the equimolar composition has the largest magnitude of the piezoelectric response. It was found that the copolymerization does not disrupt significantly a structural regularity of the more ordered smectic phase of the chiral homopolymer and, moreover, favours the appearance of less ordered smectic phases.
New side chain liquid crystalline copolymers with chiral centers in flexible spacers
MAGAGNINI, PIER LUIGI;PACI, MASSIMO
1996
Abstract
A series of new chiral side chain liquid crystalline copolymers was prepared from (S)4-(5-acryloyloxy-4-methylpentanoyloxy)-4'-octyloxybiphenyl having a chiral center in a flexible spacer and 4-hexyloxyphenyl 4-(6-acryloyloxyhexyloxy) benzoate. They were characterized by DSC, polarizing optical microscopy, piezoelectric technique and X-ray diffraction. The copolymers were shown to exhibit a rich chiral smectic phase polymorphism. A variety of smectic modifications increases with increasing number of achiral monomer units. The copolymer of the equimolar composition has the largest magnitude of the piezoelectric response. It was found that the copolymerization does not disrupt significantly a structural regularity of the more ordered smectic phase of the chiral homopolymer and, moreover, favours the appearance of less ordered smectic phases.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
