Synthesis and properties of novel fluorinated poly(amide-imide)s
Due to the low solubility of aromatic polyamide imide(PAI),its application in solution processing methods is limited.In order to improve the solution processability of PAI,reduce the cost of solvent usage and improve its thermal properties,the effects of the triphenyl ring structure and fluorine substitution on the properties of PAI were investigated.and new diamine compounds 4-[(4-amino-3,5-dimethylphenyl)]-2,6-dimethylaniline(ADPD)and 4-[(4-amino-3,5-dimethylphenyl)[4-(trifluoro-methyl)phenyl]methyl]-2,6-dimethylaniline(ADFPD)were synthesized by using benzaldehyde and p-trifluoromethyl benzaldehyde with 2,6-dimethylaniline as the raw materials.Then with trimellitic anhydride chloride to synthesize PAI containing the new struc-ture.The monomers and polymers were characterized by fourier transform infrared spectroscopy,nuclear magnetic resonance hydro-gen spectroscopy and other characterization methods,which proved the successful synthesis of the new PAI.The properties of PAI were characterized by differential scanning calorimetry,thermogravimetry analysis,water contact angle,and solvency property test.The results show that these polymers all possess good thermal stability properties as well as good solubility,with glass transition temperatures greater than 300℃,5%heat loss temperatures at 430℃and above in nitrogen environment.Maximum heat loss temperatures above 600℃under nitrogen.On the basis of the similar chemical structure,comparing the test results of PAI-1 without—CF3 and PAI-2 introduced—CF3,it is found that PAI-2 is better than PAI-1 in solubility and thermal properties,and it can significantly reduce the surface energy of the polymer,which indicates that—CF3 group can effectively improve some of the proper-ties of PAI.
NETL
NSTL
万方数据
