@article{uninimx2017, year = {2019}, volume = {26}, author = {Ram{\'o}n Pali-Casanova and Mar{\'i}a Lor{\'i}a-Bastarrachea and M. J. Aguilar-Vega and Jos{\'e} Zavala-Lor{\'i}a and Luis Dzul Lopez and Marcial Alfredo Yam Cervantes}, number = {10}, journal = {Journal of Polymer Research}, title = {Structure effect on mechanical and thermal properties in aromatic copolyamides with phenyl substituents}, keywords = {Aromatic polyamides; Polycondensation; Mechanical and thermal properties; Fractional free volume}, abstract = {Six aromatic copolyamides contanining phenyl groups were synthesized and characterized. The concentrations of the para-linked phenyl groups and meta-linked phenyl groups were varied systematically on the copolymers general structure to obtain a set of random copolyamides. Effect of copolymerization on glass transition temperature (Tg), tensile modulus (E), Tensile strength ({\ensuremath{\sigma}}) were measured. Changes in density were determined to estimate the effect on Fractional Free Volume (FFV). Results indicate that the substitution of para-linked phenyl group by meta-linked phenyl group causes an increase in tensile modulus E and tensile strength a decrease in Tg. The observed results are attributed to the asymmetric position of the linkages in the TERE and ISO isomers, because symmetric linkages, such as TERE, induces a higher packing of the polyamide chains while the asymmetry of ISO isomer inhibits packing causing an expansion in the FFV.}, url = {http://repositorio.unini.edu.mx/id/eprint/2017/} }