The characterization of fiber samples of segmented liq.-cryst. polyester (LCP) with short flexible lateral substituents are reported. The general formula of polymers is [-p-C6H4OCO-p-C6H3(R)COO-p-C6H4O(CH2 )nO-]x, with n = 2 and R = -O(CH2 )m-1CH3 (m = 1-4). The polyesters exhibit nematic liq.-cryst. behavior. At room temp., the polyesters show a cryst. phase, whose structure has been solved for the term with n = 3. Cell parameters are a = 13.20(1) Å, b = 6.48(1) Å, c = 20.11(2) Å, α = 138.3(1)°, β = 110.9(1)°, and γ = 80.8(1)° (space group P1, two chains per cell, ρc = 1.367 g cm-3 ). The mol. packing is characterized by the organizations of chains in double stacks with the lateral flexible substituents confined in between. The length of the alkoxy group affected the tilting of crystallites in the fiber samples.
Phase Behavior and Molecular Structure of Liquid-Crystalline Polyesters with Flexible Lateral Substituents
IANNELLI, Pio;PRAGLIOLA, Stefania;
1997-01-01
Abstract
The characterization of fiber samples of segmented liq.-cryst. polyester (LCP) with short flexible lateral substituents are reported. The general formula of polymers is [-p-C6H4OCO-p-C6H3(R)COO-p-C6H4O(CH2 )nO-]x, with n = 2 and R = -O(CH2 )m-1CH3 (m = 1-4). The polyesters exhibit nematic liq.-cryst. behavior. At room temp., the polyesters show a cryst. phase, whose structure has been solved for the term with n = 3. Cell parameters are a = 13.20(1) Å, b = 6.48(1) Å, c = 20.11(2) Å, α = 138.3(1)°, β = 110.9(1)°, and γ = 80.8(1)° (space group P1, two chains per cell, ρc = 1.367 g cm-3 ). The mol. packing is characterized by the organizations of chains in double stacks with the lateral flexible substituents confined in between. The length of the alkoxy group affected the tilting of crystallites in the fiber samples.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
