Synthesis and characterization of polyetherimides containing multiple ether linkages and pendent pentadecyl chains

4-(4-(4-(4-Aminophenoxy)-2-pentadecylphenoxy)phenoxy)aniline (APPPA) was synthesized starting from cashew nut shell liquid-derived bisphenol, i.e. 4-(4-hydroxyphenoxy)-3-pentadecylphenol, by nucleophilic substitution reaction with 4-chloronitrobenzene followed by reduction of the formed 4-(4-nitrophenoxy)-1-(4-(4-nitrophenoxy)phenoxy)-2-pentadecylbenzene. Three new polyetherimides containing multiple ether linkages and pendent pentadecyl chains were synthesized by one-step high-temperature solution polycondensation of APPPA in m-cresol with three aromatic dianhydrides, i.e. 3,3,4,4-oxydiphthalic anhydride, 4,4-(hexafluoroisopropylidene)diphthalic anhydride and 3,3,4,4-biphenyltetracarboxylic dianhydride. Inherent viscosities and number-average molecular weights of the polyetherimides were in the ranges 0.66-0.70 dLg(-1) and 17100-29700gmol(-1) (gel permeation chromatography, polystyrene standards), respectively, indicating the formation of reasonably high molecular weight polymers. The polyetherimides were soluble in organic solvents such as chloroform, dichloromethane, tetrahydrofuran, pyridine, m-cresol, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone and dimethylsulfoxide, and could be cast into transparent, flexible and tough films from their solutions in chloroform. The polyetherimides exhibited glass transition temperatures (T-g) in the range 113-131 degrees C. The lowering of T-g could be attributed to the combined influence of flexibilizing ether linkages and pentadecyl chains which act as packing-disruptive' groups. The temperature at 10% weight loss (T-10), determined from thermogravimetric analysis in nitrogen atmosphere, was in the range 460-470 degrees C demonstrating good thermal stability. The virtues of solubility and large gap between T-g and T-10 mean that the polyetherimides containing pendent pentadecyl chains have possibilities for both solution as well as melt processability. (c) 2015 Society of Chemical Industry