http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Crystallization Behavior of Poly(oxyethylene)s with (Alkylsulfonyl)methyl Side Groups
Lee, Jong Chan,Litt, Morton H . 한국공업화학회 1999 Journal of Industrial and Engineering Chemistry Vol.5 No.2
Thermal properties and densities of (alkylsulfonyl)methyl-substituted poly(oxyethylene)s (ASEs) were measured to determine the relationship between the crystallization and the side chain length. As the carbon number of alkyl side chain increases from one to four, both densities and Tg's decrease. However, density of (n-pentylsulfonyl)methyl-substituted poly(oxyethylene) (PeSE, five carbons) is slightly smaller than that of (n-butylsulfonyl)methyl-substituted poly (oxyethylene) (BSE, ,four carbons) and T_g of PeSE is higher than that of BSE. This phenomenon was ascribed to both the side chain crystallization and the main chain crystallization. The crystallization behavior was rationalized using DSC results and side chain density calculations.
Hydrolytic Stability of Sulfonic Acid-Containing Polyimides for Fuel Cell Membranes
Kim Hyoung-Juhn,Litt Morton H.,Shin Eun-Mi,Nam Sang Yong The Polymer Society of Korea 2004 Macromolecular Research Vol.12 No.6
The long-term stability of sulfonic acid-containing polyimides has been investigated. The hydrolytic degradation of homopolyimide and the block copolyimide comprising $27\;mol\%$ of 2,2'-bis(trifluoromethyl)benzidine and $9\;mol\%$ of m-phenylenediamine (BTFMB27mPl0[7/(3+1)]), was quantified through viscosity measurements and FT-IR spectroscopic analyses. The viscosity decrease with respect to time and the degradation rate were similar. The degrees of degradation with respect to time under ambient conditions and at elevated temperature in water were monitored by FT-IR spectroscopy. A new absorption peak was observed at $1786\;cm^{-1},$ which we corresponds to the presence of anhydride end groups formed by hydrolytic scission of the imide rings.