A novel aromatic diamine monomer bearing tertbutyl and 4-tertbutylphenyl groups,3,3'-ditertbutyl-4,4'-diaminodiphenyl-4''-tertbutylphenylmethane(TADBP),was prepared and characterized.A series of non-co...A novel aromatic diamine monomer bearing tertbutyl and 4-tertbutylphenyl groups,3,3'-ditertbutyl-4,4'-diaminodiphenyl-4''-tertbutylphenylmethane(TADBP),was prepared and characterized.A series of non-coplanar polyimides(PIs)were synthesized via a conventional one-step polycondensation from TADBP and various aromatic dianhydrides including pyromellitic dianhydride(PMDA),3,3',4,4'-biphenyltetracarboxylic dianhydride(BPDA),4,4'-oxydiphthalic anhydride(OPDA),3,3',4,4'-benzophenone tetracarboxylic dianhydride(BTDA)and 4,4'-(hexafluoroisopropylidene)dipthalic anhydride(6FDA).All PIs exhibit excellent solubility in common organic solvents such as N,N-dimethylformamide(DMF),N,N-dimethylacetamide(DMAc),N-methyl-2-pyrrolidone(NMP),dimethyl sulfoxide(DMSO),chloroform(CHCl3),tetrahydrofuran(THF),and so on.Furthermore,the obtained transparent,strong and flexible polyimide films present good thermal stability and outstanding optical properties.Their glass transition temperatures(Tgs)are in the range of 298 to 347℃,and 10%weight loss temperatures are in excess of 490℃with more than 53%char yield at 800℃in nitrogen.All the polyimides can be cast into transparent and flexible films with tensile strength of 80.5-101 MPa,elongation at break of 8.4%-10.5%,and Young's modulus of 2.3-2.8 GPa.Meanwhile,the PIs show the cutoff wavelengths of 302-356 nm,as well as low moisture absorption(0.30%-0.55%)and low dielectric constant(2.78-3.12 at 1 MHz).展开更多
A novel aromatic diamine monomer, 3,3＇-diisopropyl-4,4＇-diaminodiphenyl-3＂,4＂-difluorophenylmethane （PAFM）, was successfully synthesized by coupling of 2-isopropylaniline and 3,4-difluorobenzaldehyde. The aro- m...A novel aromatic diamine monomer, 3,3＇-diisopropyl-4,4＇-diaminodiphenyl-3＂,4＂-difluorophenylmethane （PAFM）, was successfully synthesized by coupling of 2-isopropylaniline and 3,4-difluorobenzaldehyde. The aro- matic diamine was adopted to synthesize a series of fluorinated polyimides by polycondensation with various dian- hydrides： pyromellitic dianhydride （PMDA）, 3,3＇,4,4＇-biphenyltetracarboxylic dianhydride （BPDA）, 4,4＇-oxydiph- thalic anhydride （ODPA） and 3,3＇,4,4＇-benzophenone tetracarboxylic dianhydride （BTDA） via the conventional one-step method. These polyimides presented excellent solubility in common organic solvents, such as N,N-dimeth- ylformamide （DMF）, N,N-dimethyl acetamide （DMAc）, dimethyl sulfoxide （DMSO）, N-methyl-2-pyrrolidone （NMP）, chloroform （CHC13）, tetrahydrofuran （THF） and so on. The glass transition temperatures （Tg） of fluorinated polyimides were in the range of 260--306 ℃ and the temperature at 10% weight loss in the range of 474--502 ℃ Their films showed the cut-off wavelengths of 330--361 nm and higher than 80% transparency in a wavelength range of 385--463 nm. Moreover, polymer films exhibited low dielectric properties in the range of 2.76--2.96 at 1 MHz, as well as prominent mechanical properties with tensile strengths of 66.7--97.4 MPa, a tensile modulus of 1.7--2.1 GPa and elongation at break of 7.2%- 12.9%. The polymer films also showed outstanding hydrophobicity with the contact angle in the range of 91.2°--97.9°.展开更多
基金supported by the National Natural Science Foundation of China(Nos.51163003,21264005 and 51263005)the fund of Guangxi Natural Science Foundation(Nos.2014GXNSFAA118040,2013GXNSFDA019008)Guangxi Small Highland Innovation Team of Talents in Colleges and Universities,and Fund。
文摘A novel aromatic diamine monomer bearing tertbutyl and 4-tertbutylphenyl groups,3,3'-ditertbutyl-4,4'-diaminodiphenyl-4''-tertbutylphenylmethane(TADBP),was prepared and characterized.A series of non-coplanar polyimides(PIs)were synthesized via a conventional one-step polycondensation from TADBP and various aromatic dianhydrides including pyromellitic dianhydride(PMDA),3,3',4,4'-biphenyltetracarboxylic dianhydride(BPDA),4,4'-oxydiphthalic anhydride(OPDA),3,3',4,4'-benzophenone tetracarboxylic dianhydride(BTDA)and 4,4'-(hexafluoroisopropylidene)dipthalic anhydride(6FDA).All PIs exhibit excellent solubility in common organic solvents such as N,N-dimethylformamide(DMF),N,N-dimethylacetamide(DMAc),N-methyl-2-pyrrolidone(NMP),dimethyl sulfoxide(DMSO),chloroform(CHCl3),tetrahydrofuran(THF),and so on.Furthermore,the obtained transparent,strong and flexible polyimide films present good thermal stability and outstanding optical properties.Their glass transition temperatures(Tgs)are in the range of 298 to 347℃,and 10%weight loss temperatures are in excess of 490℃with more than 53%char yield at 800℃in nitrogen.All the polyimides can be cast into transparent and flexible films with tensile strength of 80.5-101 MPa,elongation at break of 8.4%-10.5%,and Young's modulus of 2.3-2.8 GPa.Meanwhile,the PIs show the cutoff wavelengths of 302-356 nm,as well as low moisture absorption(0.30%-0.55%)and low dielectric constant(2.78-3.12 at 1 MHz).
文摘A novel aromatic diamine monomer, 3,3＇-diisopropyl-4,4＇-diaminodiphenyl-3＂,4＂-difluorophenylmethane （PAFM）, was successfully synthesized by coupling of 2-isopropylaniline and 3,4-difluorobenzaldehyde. The aro- matic diamine was adopted to synthesize a series of fluorinated polyimides by polycondensation with various dian- hydrides： pyromellitic dianhydride （PMDA）, 3,3＇,4,4＇-biphenyltetracarboxylic dianhydride （BPDA）, 4,4＇-oxydiph- thalic anhydride （ODPA） and 3,3＇,4,4＇-benzophenone tetracarboxylic dianhydride （BTDA） via the conventional one-step method. These polyimides presented excellent solubility in common organic solvents, such as N,N-dimeth- ylformamide （DMF）, N,N-dimethyl acetamide （DMAc）, dimethyl sulfoxide （DMSO）, N-methyl-2-pyrrolidone （NMP）, chloroform （CHC13）, tetrahydrofuran （THF） and so on. The glass transition temperatures （Tg） of fluorinated polyimides were in the range of 260--306 ℃ and the temperature at 10% weight loss in the range of 474--502 ℃ Their films showed the cut-off wavelengths of 330--361 nm and higher than 80% transparency in a wavelength range of 385--463 nm. Moreover, polymer films exhibited low dielectric properties in the range of 2.76--2.96 at 1 MHz, as well as prominent mechanical properties with tensile strengths of 66.7--97.4 MPa, a tensile modulus of 1.7--2.1 GPa and elongation at break of 7.2%- 12.9%. The polymer films also showed outstanding hydrophobicity with the contact angle in the range of 91.2°--97.9°.
