72108-22-6Relevant articles and documents
Preparation of 1,2-bis(4-hydroxyphenyl)-2-hydroxypropanes
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Example 1, (2008/06/13)
The present invention relates to the preparation of substituted or unsubstituted 1,2-bis(4-hydroxyphenyl)-hydroxyaliphatics such as 1,2-bis(4-hydroxyphenyl)-2-hydroxypropanes by reacting substituted or unsubstituted 1,2-bis(4-hydroxyphenyl)-halogen substituted aliphatics such as 1,2-bis(4-hydroxyphenyl)-2-chloropropanes in the presence of a base and water.
Synthesis and Characterization of Thermotropic Polyethers and Copolyethers Based on 4,4'-dihydroxy-α-methylstilbene and Flexible Spacers Containing Odd Numbers of Methylene Units
Percec, V.,Asami, K.,Tomazos, D.,Feijoo, J. L.,Ungar, G.,Keller, A.
, p. 47 - 66 (2007/10/02)
This paper describes the synthesis and characterization of thermotropic polyethers and copolyethers based on 4,4'-dihydroxy-α-methylstilbene (HMS) and flexible spacers containing odd number of methylene units .The polyethers HMS-X are binary copolymers containing structural units derived from the two constitutional isomers of HMS and the flexible spacer.The binary copolymers HMS-X/Y (A/B) contain four structural units derived from combinations of the two constitutional isomers of HMS and the two flexible spacers.The following polymers and copolymers were synthesized and characterized: HMS-5, HMS-7, HMS-9, HMS-11, HMS-13(A/B), HMS-5/7(A/B), HMS-5/9(A/B), HMS-5/11(A/B), HMS-7/9(A/B), HMS-9/11(A/B), and HMS-9/13(A/B).All polymers had number average molecular weights higher than 15,000 and exhibited an enantiotropic nematic mesophase and several crystalline phases.Both the crystalline and the liquid crystalline phases are kinetically controlled i.e., their thermal transition temperatures and associated enthalpy changes are dependent on the heating rate and thermal history of the sample.These results led to the conclusion that for high molecular weight semi-flexible liquid crystalline polymers non-equilibrium states exist both in the liquid crystalline and crystalline phases.Quasi-equilibrium nematic-isotropic transition temperatures and enthalpy changes were obtained either from the first heating scan or after suitable annealing of the polymer sample.