Design And Preparation Of New Polymeric Liquid Crystal Compounds

With the good performance of liquid crystal, acrylate liquid, one of the liquid crystal compounds, has draw much attention and had been synthesized abundance in recent years.Different with the common liquid crystal monomer linked by the ester, this paper attempts to design and synthesize a novel polymerizable liquid crystal compound, which is linked by methoxyl, and aims for new approach for the compound.First of all, phenolic hydroxyl groups were protected by allyl to synthesis the liquid crystal intermediates M1. The experimental conditions of each reaction were determined as follows:1) The most suitable conditions to synthesize(4-Allyloxy-phenyl)-methanol were elaborated as follows:1eq hydroxy benzene methanol,1.1eq allyl bromide,1.2eq potassium carbonate and 4eq acetone were reacted about 7h under the normal pressure and the reflux temperature.2) The most suitable conditions to synthesize 1-Allyloxy-4-chloromethyl-benzene were elaborated as follows:1eq(4-Allyloxy-phenyl)-methanol dissolved in 5eq dichloromethane with stirring slowly, thionyl chloride was drop into the reaction flask when the temperature below 0℃, then reflux for 4 hours.3) The most suitable conditions to synthesize compounds M1 were elaborated as flows: 1eq hydroquinone, 3eq 1-Allyloxy-4-chloromethyl-benzene and 3eq potassium carbonate were added to the reaction flask and stirred 12 hours at 60℃ under the protection of nitrogen.Secondly,a new type of liquid crystal compounds I was synthesized successfull y through a series of reaction. 1) Hydroquinone acted as original material, 4-(3- hy droxyl propoxy) benzaldehyde was obtained by reacting with 1-chloro-3-hydroxypro pane,2) Acetyl chloride protect alcohol hydroxyl through esterification,3) Benzyl alc ohol was obtained by reducing benzaldehyde,4) Benzyl alcohol reacted with thionyl chloride to get benzyl chloride,5) Double ester compounds was generated by ether ificating with hydroquinone,6) After hydrolysis, double alcohols compounds was o btained,7) Finally the double alchol compounds reacted with acryloyl chloride to ob tain the final liquid crystal compounds I. The monomer’s melting point was charac terized with DSC. The chemical structures of the monomer were characterized withinfrared spectroscopy(FI-IR) and nuclear magnetic resonance(1H-NMR),and make sure the composition of the liquid crystal monomer.Finally, the other new liquid crystal compound II was successfully synthesized through a series of reaction. 1) We choose hydroquinone and two benzyl alcohol acted as starting materials to synthesis 4-benzyloxy-phenol, 2) 3-(4-benzylphenoxy)propane-1- alcohol was obtained by reaction with 1-chloro-3-hydroxypropane; 3) 4-(3-hydroxylpropoxy)phenol was got by removing the benzyl;4) Benzyl chloride was synthesized through react diphenyl methanol with thionyl chloride, 5) An etherific ation reaction between 1,4-bis-chloromethyl-benzene and 4-(3-hydroxypropyloxygenra dicals)phenol was reacted in order to get 3-(4-(-(3-hydroxypropyloxygenradicals)met hyl)phenoxymethyl)propane-1-alcohol; 6) Liquid crystal compound II was obtained b y reaction with acryloyl chloride. The monomer melting point was characterized wi th DSC. The chemical structures of the monomer were characterized with infrared spectroscopy(FI-IR) and nuclear magnetic resonance(1H-NMR) and make sure the composition of the liquid crystal monomer.