Step heating melt polycondensation was adopted in the preparation of polyamides based on 1,16-octadecane diacid and alpha,omega-(CH2)(2u), diamines (n = 1-6). The structure was confirmed by various spectroscopic techniques (IR, Raman, H-1-NMR, and C-13-NMR). High molecular masses were obtained only in the presence of an excess of diamine and when the diamine possessed low volatility. The molecular masses were between (0.94 and 2.1) x 10(4) Da for all polyamides under consideration. An excellent correlation between size exclusion chromatography and H-1-NMR data was demonstrated in the measurement of the degree of polymerization. The melting temperatures of the polyamides decreased from polyamide 12 18 to polyamide 2 18 as the amide density along the molecular chain declined. No significant variation was observed in the glass-transition and decomposition temperatures of the polyamides that were obtained.
Synthesis and characterization of polyamides X 18 / X.W. Cui, W. H. Li, D. Y. Yan, C. M. Yuan, G. Di Silvestro. - In: JOURNAL OF APPLIED POLYMER SCIENCE. - ISSN 0021-8995. - 98:4(2005), pp. 1565-1571.
Synthesis and characterization of polyamides X 18
G. Di Silvestro
2005
Abstract
Step heating melt polycondensation was adopted in the preparation of polyamides based on 1,16-octadecane diacid and alpha,omega-(CH2)(2u), diamines (n = 1-6). The structure was confirmed by various spectroscopic techniques (IR, Raman, H-1-NMR, and C-13-NMR). High molecular masses were obtained only in the presence of an excess of diamine and when the diamine possessed low volatility. The molecular masses were between (0.94 and 2.1) x 10(4) Da for all polyamides under consideration. An excellent correlation between size exclusion chromatography and H-1-NMR data was demonstrated in the measurement of the degree of polymerization. The melting temperatures of the polyamides decreased from polyamide 12 18 to polyamide 2 18 as the amide density along the molecular chain declined. No significant variation was observed in the glass-transition and decomposition temperatures of the polyamides that were obtained.File | Dimensione | Formato | |
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