4,4*-Dihydroxy-a-methylstilbene

Recently Krigbaum and coworkers prepared cholesteric polyesters from the reaction of 4,4 -dihydroxy-a-methylstilbene with mixtures of (-f) 3-methyladipic acid and adipic acid. They could change the morphology of the cholesteric state formed by the (4-) 3-methylapidic acid homopolymer by mixing it either with a low molecular... [Pg.129]

Sue Sue, H.-J., Earls, J. D., Hefrier Jr., R. E. Fracture behaviour of liquid crystal epoxy resin systems based on diglycidyl ether of 4,4 -dihydroxy-a-methylstilbene. Part 11 Effect due to blending with TACTIX 556 epoxy resin and phenolic monomers. J. Mater. Sci. 32 (1997) 4039 046. [Pg.541]

Hydroxyether of 4,4 -dihydroxy-a-methylstilbene Single Tg Blend had I II = 1 1 Bruggeman and Tinnemans (1999)... [Pg.1992]

The goal of this paper is to review our present information on the synthesis and characterization of LC polyethers and copolyethers based on 4,4 -dihydroxy-a-methylstilbene (HMS) and 4,4 -dihydroxybiphenyl (HB) with a, (i)-dibromoalkanes. [Pg.134]

Dihydroxy-a-methylstilbene (HMS) was synthisized by the condensation of chloroacetone with phenol in the presence of concentrated sulfuric... [Pg.135]

Table 1. Synthesis and Characterization of 4,4 -Dihydroxy-a-methylstilbene Polyformal and Polyethers... [Pg.140]

It is seen from Table I that parameters F and S are essentially decreased during the DGET cure to the limit value equal to 0.5 for ultimate conversion (19). The close value of the order parameter for network polymers based on diglyddyl ethers of 4,4 -dihydroxy-a-methylstilbene were obtained by Ober and coworkers (2, 20). [Pg.377]

Figure 12. Top ESR spectra of main chain liquid crystalline poly(ether) DHMS-7,9 (based on 4,4 -dihydroxy-a-methylstilbene and mixed aliphatic spacers of 7 and 9 methylene groups), spin-labeled with CSL (3)5-doxyl-5a-cholestane). Solid lines experimental dashed lines simulated. Bottom average rotational diffusion coefficient, R=(Rx °t)-...

Sue et al. [350] studied the morphologies of various diglycidyl ethers of 4,4 -dihydroxy-a-methylstilbene-based liquid crystalline epoxy (LCE) formulations used as matrices for high performance composites by polishing, to 0.3jum finish, followed by etching with KMn04 in a... [Pg.186]

Percec V, Nava H, Jonsson H (1987) Functional polymers and sequential copolymers by phase transfer catalysis. 24. The influence of molecular weight on the thermotropic properties of a random copolyether based on 1,5-dibromopentane, 1,7-dibromoheptane, and 4,4 -dihydroxy-a-methylstilbene. J Polym Sci A Polym Chem 25 1943-1965... [Pg.220]

The addition of either a low molecular weight or polymeric liquid crystal, / -azoxyanisole and poly(4,4 -dihydroxy-a-methylstilbene adipate) respectively, to cholesteric poly(4,4 -dihydroxy-a-methylstilbene 3-methyladipate) has been also investigated. An extension of the helical pitch was achieved, according to the shift to the visible range of the maximum reflection... [Pg.31]

More recently it has been proved that it is possible to prepare cholesteric homopolymers.Krigbaum et al. observed fan-like texture for polyester synthesized from 4,4 -dihydroxy-a-methylstilbene and (+)-3-methyladipic acid. These authors suggested the formation of a strongly twisted cholesteric. Indeed, in low molecular weight cholesterics with high twist, the defects and textures resemble those of smectics, especially smectic A. Such cholesteric substances may yield non-planar textures. They may appear in fan-shaped, focal conic or polygonal textures. In the case of... [Pg.141]

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