| Traditional liquid crystal monomer can not meet the function requirement of photoelectric display materials and high-grade liquid crystal materials.In recent years,the study has found that liquid crystal compounds of naphthalene derivative with superior physical properties,have become a hot spot in the field of liquid crystal display materials research.Liquid crystal materials of naphthalene change characteristics of traditional liquid crystal with single ring skeleton and possess better photoelectric performance,which have received more and more attention.Because naphthalene derivative liquid crystal is added to the mixture liquid crystal not only has good compatibility,and can meet requirements of wide mesophase temperature range,large dielectric anisotropy,low threshold voltage performance,cyclohexane high-end LCD performance better than the widely used.It can be predicted that the compounds as practical liquid crystal material has a wide application prospect.This paper is the study of liquid crystal material containing naphthalene.Non liquid crystal monomer containing naphthalene and liquid crystal monomer and silane grafting copolymerization,finally get the three series polymer with liquid crystal properties.The experimental results show that the introduction of naphthalene in the crystal,can obtain a wide range of the liquid crystal.According to reports from the literature,more and more people is studying liquid crystal monomer containing naphthalene.This paper is a study of side chain liquid crystalline polymers containing naphthalene.Thus this study has great theoretical value and research significance.Six kinds of monomers were synthesized in this paper,they are 4-Allyloxy-benzoic acid-4'-acetoxy-biphenyl-4-ylester(Mi);4-Allyloxy-benzoic acid-4' caproic acid-biphenyl-4-ylester(M2);[4-(1-((1-4-hydroxyphenyl)ethylidene)hydrazono)ethyl]phenyl-4(allyoxy)benzoate(M3);[4-(1-((1-4-acetoxyphenyl)ethylidene hydrazono ethyl)phenyl-4-(allyloxy)benzoate](M4);7-hydroxynaphthalen-2-yl-4-(allyloxy)benzoate(M5);7-acetoxynaphthaten-2-yl-4-(allyloxy)benzoate(M6).According to the experimental conditions,Then M1,M6 and a poly methyl hydrogen siloxane(PMHS)was grafted homopolymer,getting side chain liquid crystalline polymers containing naphthalene P1;With the same way,M2,M6 and a poly methyl hydrogen siloxane(PMHS)was grafted homopolymer,geting P2;Making M3 replace M2,the others are the same,geting P3;Through the infrared spectrometer(IR),differential scanning calorimeter(DSC)and polarizing optical microscopy(POM)test,the experimental results are as follows:(1)Through IR analysis,all of the monomers and polymers are in accord with molecular design.(2)Through DSC analysis,M1-M4 are liquid crystal monomers.The liquid crystal region of Mi was 114 ?-260 ?;M2 was 92-102 ?-163 ?-244 ?,which had the change of texture;M3 was 174 ?-281 ?;and M4 was 181 ?-278 ?.Ms and M6 are not liquid crystal monomers,and the melting points are respectively 140 ? and 117 ?.P1,P2 and P3 series all have a glass transition(Tg),and the widest range of liquid crystal are respectively 120 ?,205? and 176 ?.In addition to M6 whose molar ratio is 10%,Tg of Pi series are increased and Ti were increased,too;In addition to M6 whose molar ratio is 1%,Tg of P2 series are increased and Ti were irregular;In addition to M6 whose molar ratio is from 0%-10%,Tg of P3 series are increased and the others are not the same.Ti first increased and then decreased.The introduction of the non liquid crystal monomer containing naphthalene has broadened the liquid crystal range of Pi,P2 and P3.(3)Through POM analysis,it was found that Mi,M3 and M4 are the heat induced tautomerism nematic liquid crystal monomers.M2 is nematic-smectic liquid crystal monomer;polymer Pi series is nematic phase liquid crystal;the P2 and P3 series are nematic phase liquid crystal with color texture. |
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