| In recent years,with the continuous development of liquid crystal chemistry,the design and synthesis of new type of liquid crystal compounds has been the trend of the times.Star liquid crystal is a central atom or group with a number of dobby liquid crystal molecules composed of primitives.Star the synthesis of liquid crystal in theory brokes through the traditional long chain of rod-like liquid crystal.It is with three or more than structure primitives directly connected to a central primitives,becomes a new type of liquid crystal.Swallow-tailed type liquid crystal is at the end of the ends of the rod-shaped molecules containing multiple flexible substituent of dobby liquid.As the swallow tail length of different substituents on both ends,it will present smectic,nematic and cholesteric crystal phase.Azo type of liquid crystal is containing azo group(-N = N-).When it is heated or by different wavelengths of light,this kind of liquid crystal molecules with optical activity,produce light isomerism,so there will be a special optical properties.This makes azo liquid crystal in optical information processing,optical storage and optical holography technology has great application prospect.This paper is conducted by star liquid crystal compounds containing azo groups,swallow-tailed type liquid crystal compounds containing azo groups of synthesis and will swallow-tailed type liquid crystal monomer containing azo groups into the main chain of the flexible polysiloxane preparation of new type of side chain liquid crystal polymer research.This not only enrich the kinds of new type of liquid crystal compounds,also for the design and synthesis has the specific performance of side chain liquid crystal polymer provides a certain theoretical basis.Based on the careful study of the many domestic and foreign literatures,this paper design and synthesis of the containing different side substituent of 6 kinds of azo liquid crystal arm,24 kinds of star liquid crystal compounds,2 kinds of swallow-tailed liquid crystal compounds,and two series of azo side chain liquid crystal polymer.Their performance by FT-IR,DSC,POM,1H-NMR four kinds of test methods,have been characterized.Contains different side substituent of 6 kinds of azo liquid crystal arm respectively:4-nitroazobenzene alkyloxyethyl formyl pentanoic acid(A),4-nitroazobenzene alkyloxyethyl formyl nonanoic acid(B),4-methoxy azobenzene alkyloxyethyl formyl pentanoic acid(C),4-methoxyazobenzene alkyloxyethyl formyl nonanoic acid(D),4-chlorineazobenzene alkyloxyethyl formyl pentanoic acid(E),4-chlorinezobenzene alkyloxyethyl formyl nonanoic acid(F).Star liquid crystal compounds are 6 kinds of azo liquid crystal arm through esterification reaction with phloroglucinol,pentaerythritol,xylose and glucose reaction.They are:tris(4-substitutions oxygen azobenzene formyl pentanoic acid)phloroglucinol ester(MX1、MX9 and MX 17),tris(4-substitutions oxygen azobenzene formyl pelargonic acid)phloroglucinol ester(MX2、MX10 and MX18),four(4-substitutions oxygen azobenzene formyl pentanoic acid)pentaerythritol ester(MX3、MX11 and MX19),four(4-substitutions oxygen azobenzene formyl pelargonic acid)pentaerythritol ester(MX4、MX12 and MX20),four(4-substitutions oxygen azobenzene formyl pentanoic acid)xylose ester(MX5、MX13 and MX21),four(4-substitutions oxygen azobenzene formyl pelargonic acid)xylose ester(MX6、MX14 and MX22),five(4-substitutions oxygen azobenzene formyl pentanoic acid)glucose ester(MX7、MX15 and MX23),five(4-substitutions oxygen azobenzene formyl pelargonic acid)glucose ester(MX8、MX16 and MX24).Azo swallow-tailed type liquid crystal compounds with gallic acid as the core is obtained by esterification reaction.They are:4-(3,4,5-tris(4-(thirteen alkyl formyl oxygen radicals)benzoyloxy-4’-(p-allyloxy)-benzoyloxy-benzene oxygen formyl azobenzene(MY1),4-(3,4,5-tris(4-methoxy butyl azo benzoyl oxygen radicals formyl oxygen radicals)benzoyloxy-4,-(p-allyloxy)-benzoyloxy-benzene oxygen formyl benzene(MY2).The monomer MY1,MY2 respectively with methyl hydrogen siloxane polymerization,compound two series of P1 and P2 dovetail type of side chain liquid crystal polymer.For the above synthesis of monomer and side chain liquid crystal polymers using FT-IR,1H-NMR,DSC,POM,studied the structure and properties,the experimental results show that the monomer and polymers have liquid crystal,the chondrules schlieren and silky texture appeared in the process of heating and cooling.Combined with the molecular structure of preliminary conclude that they are hot nematic phase liquid crystal.Azo star that contain the same nuclear liquid crystal monomers,due to the different types of end substituents,caused their melting point and clear window will be different.As the growth of the alkyl chain their melting point and clear window will reduce,liquid crystal interval will narrow.Synthesis of side chain azo liquid crystal polymer that P1,P2 series are typical non-crystalline liquid crystal polymers.They appear respectively when heating the glass transition and liquid crystal isotropic phase shift of two phase transition. |
