摘要
以4，4’-（α,ω-辛二酰氧）二苯甲酰氯（M1）、2，5-二（对十二烷氧基苯甲酰氧基）对苯二酚（M2）和顺式-4，4＇-双（4-羟基苯基偶氮）二苯并-14-冠-4（M3）为单体，通过溶液共缩聚反应，合成了一系列含X-型二维液晶基元和顺式-4，4＇-双（4-羟基苯基偶氮）二苯并-14-冠-4冠醚环的主链型液晶共聚酯．单体1（M1）由对羟基苯甲酸和辛二酰氯，通过酯化和取代反应制备，单体2（M2）由2，5-二羟基苯醌和对十二烷氧基苯甲酰氯通过酯化和还原反应制备，单体3（M1）由顺式-二氨基二苯并-14-冠-4和苯酚通过重氮化和偶联反应制备．共聚酯的分子量不高，[η]在0．35～0．25dL／g之间．单体的化学结构通过IR、UV、^1H—NMR、MS和元素分析等方法确证．共聚酯的外观为黄色粉状固体，除CP9外，室温下不溶于CHCl3和THF溶剂．共聚酯的性质采用GPC、[η]、DSC、TG、WAXD和POM等方法进行了研究．发现所有的共聚酯加热到各自的熔融温度以上都能形成液晶态，在液晶态可以观察到向列相的丝状织构或纹影织构．共聚酯的熔融温度（Tm）和各向同性温度（Ti）随共聚酯分子中顺式-4，4’-双（4-羟基苯基偶氮）二苯并-14-冠-4用量的改变呈规律性变化．WAXD研究进一步证实了共聚酯的液晶性．
A novel series of main chain liquid crystalline copolyesters with X-shaped two-dimensional mesogenic units and crown ether cycles of cis-4,4＇-bis（4-hydroxyphenylazo） dibenzo-14-crown-4 was synthesizeed via solution cocondensation polymerizations from 4, 4＇-（ α,ω-octanedioylxy）dibenzoyl dichloride （M1）, 2, 5-bis （p-dodecyloxybenzoyloxy）hydro-quinone （M2） and cis-4,4＇-bis（4-hydroxyphenylazo）dibenzo-14-crown-4 （M3） as the monomers. Monomer M1 was synthesized by esterification and substitution reaction of p-hydroxybenzoic acid and octanedioyl chloride. Monomer M2 was synthesized by esterfication and reduction reaction of 2, 5- dihydroxybenzoquinone and p-dodecyloxybenzoyl chloride. Monomer （M3 ） was synthesized by diazotization and coupling reaction of cis-diaminodibenzo-14-crown-4 and phenol. The molecular weights of copolyesters are not high, and the [η] of the copolyesters ranges from 0.35 - 0.25 dL/g. The monomer structures were identified by using elementary analysis, IR, UV, ^1H-NMR and MS etc. All the copolyester samples are yellowish powders and insoluble at room temperature in THF and CHCl3 except for sample CP9. The properities of copolyesters were investigated by using GPC, [ η] ,DSC,TG,WAXD and POM. It was found that all the copolyesters went into liquid-crystal phase when they were heated over their melting temperature （ Tm ） . The thread texture and schlieren texture can be observed. Their melting temperature and isotropic temperature（ Ti ） change regularly with varying the cis-4,4＇-bis（4- hydroxyphenylazo）dibenzo-14-crown-4 unit content in the copolyesters. The WAXD study illustrated that the copolyesters are liquid crystalline with a nematic phase. A dispersive peak at 2θnear 20°appeared in their WAXD patterns, which is a typical character for quenched nematic liquid crystal copolyesters.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2006年第2期236-240,共5页
Acta Polymerica Sinica
基金
国家自然科学基金(基金号29974026)
河南省自然科学基金(基金号0211021100)
河南省教育厅自然科学基金(基金号200215000004)资助项目
