초록 |
In this study, after preparing a styrene-co-methacrylic acid (PSMAA) copolymer containing about 31 mol% of acid repeating units, the acid functional group was converted to amide using n-alkylamine (C4, C6, C8, C12, C18). The mechanical properties of these copolymers were measured by DMA. It was found that as the amount of n-octyl (C8) amine increased, the degree of amide formation increased from 3.5 to 7.8 mol%. It was also observed that the degree of amidation increased as the chain length of the n-alkylamine increased from C4 to C18. In the course of this study, it was found that the glass transition temperature of the copolymer was significantly influenced by both the amidation degree and the acid content of the copolymer. Especially, the former effect was more operative than the latter effect, which was due to the internal plasticization by the long alkyl chains of the alkylamines. |