A novel biphenyl side-chained diamine with alkyloxy spacer and alkyloxy tail,4＇-butoxy-4-（3,5-diaminobenzoyloxy）hexyloxybiphenyl（C6BBC4）,was synthesized and characterized by FTIR and 1 H NMR.A series of polyimide...A novel biphenyl side-chained diamine with alkyloxy spacer and alkyloxy tail,4＇-butoxy-4-（3,5-diaminobenzoyloxy）hexyloxybiphenyl（C6BBC4）,was synthesized and characterized by FTIR and 1 H NMR.A series of polyimide（PI） films with different side chain contents was synthesized from biphenyltetracarboxylicdianhydride（BPDA）,4,4＇-oxydianiline（ODA） and C6BBC4,and their thermal properties,optical transparency and liquid crystal alignment property,and so on,were investigated by thermogravimetric analysis（TGA）,differential scanning calorimetry（DSC）,crystal rotation method,polarizing microscopy and UV-Vis spectra.With the content of side chained diamine increasing from 0 to 100%,the η inh of poly（amide acid）（PAA） decreased rapidly from 3.0 to 0.51,the glass transition temperature（T g） of polyimides（PIs） decreased from 274 ℃ to 203 ℃ and the Vis-light transmittance of alignment films substantially increased.As for the alignment properties,the pretilt angle of PI alignment films without rubbing could reach 90° when the content of C6BBC4 was 60% or more.At the same time,the alignment stability could meet the industrial requirements.It was considered that the alkoxy spacer,the biphenyl unit and the alkoxy tail may all play important roles in achieving a large pretilt angle even up to 90°,and the introduction of only the alkoxy spacer or alkoxy tail can also improve the pretilt angle,but not by much.展开更多
A novel diamine 4-[（4＇-butoxyphenoxy）carbonyl]phenyl-3＂,5＂-diaminobenzoate （BCDA） was synthesized from 4-butoxyphenol, 4-hydroxybenzoic acid and 3,5-dinitrobenzoic acid through four main intermediates, and a se...A novel diamine 4-[（4＇-butoxyphenoxy）carbonyl]phenyl-3＂,5＂-diaminobenzoate （BCDA） was synthesized from 4-butoxyphenol, 4-hydroxybenzoic acid and 3,5-dinitrobenzoic acid through four main intermediates, and a series of polyimides were also synthesized. All the intermediates and the final product were characterized by FTIR and 1H-NMR. The key step in synthesis route is selective hydrolyzation of two ester groups in 4-butoxyphenyl-4＇-acetoxybenzoate, by adjusting the reaction temperature and the concentration of ammonia, shorteding the reaction time. The properties of the novel polyimides, such as the aggregation structures, glass transition temperature, solubility and the pretilt angles, were carded out.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.50773044,50973073)
文摘A novel biphenyl side-chained diamine with alkyloxy spacer and alkyloxy tail,4＇-butoxy-4-（3,5-diaminobenzoyloxy）hexyloxybiphenyl（C6BBC4）,was synthesized and characterized by FTIR and 1 H NMR.A series of polyimide（PI） films with different side chain contents was synthesized from biphenyltetracarboxylicdianhydride（BPDA）,4,4＇-oxydianiline（ODA） and C6BBC4,and their thermal properties,optical transparency and liquid crystal alignment property,and so on,were investigated by thermogravimetric analysis（TGA）,differential scanning calorimetry（DSC）,crystal rotation method,polarizing microscopy and UV-Vis spectra.With the content of side chained diamine increasing from 0 to 100%,the η inh of poly（amide acid）（PAA） decreased rapidly from 3.0 to 0.51,the glass transition temperature（T g） of polyimides（PIs） decreased from 274 ℃ to 203 ℃ and the Vis-light transmittance of alignment films substantially increased.As for the alignment properties,the pretilt angle of PI alignment films without rubbing could reach 90° when the content of C6BBC4 was 60% or more.At the same time,the alignment stability could meet the industrial requirements.It was considered that the alkoxy spacer,the biphenyl unit and the alkoxy tail may all play important roles in achieving a large pretilt angle even up to 90°,and the introduction of only the alkoxy spacer or alkoxy tail can also improve the pretilt angle,but not by much.
基金We are grateful for the financial support from the National Natural Science Foundation of China(No,50433010)Doctoral Fund of Ministry of Eduction of China(No.20040610028),
文摘A novel diamine 4-[（4＇-butoxyphenoxy）carbonyl]phenyl-3＂,5＂-diaminobenzoate （BCDA） was synthesized from 4-butoxyphenol, 4-hydroxybenzoic acid and 3,5-dinitrobenzoic acid through four main intermediates, and a series of polyimides were also synthesized. All the intermediates and the final product were characterized by FTIR and 1H-NMR. The key step in synthesis route is selective hydrolyzation of two ester groups in 4-butoxyphenyl-4＇-acetoxybenzoate, by adjusting the reaction temperature and the concentration of ammonia, shorteding the reaction time. The properties of the novel polyimides, such as the aggregation structures, glass transition temperature, solubility and the pretilt angles, were carded out.
