Sorption Isotherm Analysis of Water by Hydrophilic Polymer Composed of Different Adsorption Sites Using Modified BET Equation
✍ Scribed by Hiromi Gocho; Akihiko Tanioka; Toshinari Nakajima
- Book ID
- 102580377
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 132 KB
- Volume
- 200
- Category
- Article
- ISSN
- 0021-9797
No coin nor oath required. For personal study only.
✦ Synopsis
groups but also by the higher order structure of the polymer In this study, two typical modeling samples composed of vinyl (1,2). The continuity of hydroxyl groups takes part in the acetate (VAc) and vinyl alcohol (VA) copolymer were prepared crystal formation. On the other hand, some existing acetoxyl in order to investigate the relationship between polymer structure groups disturb the crystal formation by continuous hydroxyl and water uptake. One consisted of homogeneously acetylated groups, and continuous acetoxyl groups form the amorphous samples in which the hydroxyl group and acetoxyl group were polymer structure. The heat of hydration for the hydroxyl distributed randomly, and the other consisted of the heterogegroup is larger than that for the acetoxyl group (3, 4). The neously acetylated samples which were composed of block copolycontinuity of the functional group and the alternately remer of poly(VA) and poly(VAc-VA). The sorption isotherms of peating extent of the two different groups also affect the water vapor by those samples with various contents of hydroxyl and acetoxyl groups were measured. The BET adsorption theory adsorption energy. It is very important in the material design was modified for the system which has two different kinds of for fiber making and film formation of polymers to examine energy levels in water adsorption sites, that is, a hydroxyl group the effect of functional group distribution on the water sorpand an acetoxyl group, and applied in order to analyze the obtion (5, 6). In this study, two typical modeling samples were tained sorption isotherms. The homogeneously acetylated VAc/ prepared in order to investigate the relationship between VA copolymer was amorphous polymer, and the heterogeneously polymer structure and water uptake. One was the homogeacetylated VAc/VA copolymer was a partially crystallized polyneously acetylated samples in which the hydroxyl group and mer. The number of adsorption sites in the homogeneously aceacetoxyl group are distributed randomly and the other was tylated samples was larger than that in the heterogeneously acethe heterogeneously acetylated samples which were comtylated sample. On the other hand, the interaction energy between posed of a block copolymer of poly(VA) and poly(VActhe hydroxyl group and water in the heterogeneously acetylated sample was much larger than that in the homogeneously ace-VA). The sorption isotherms of water vapor by those samtylated sample based on examination with the modified BET equaples with varying contents of hydroxyl and acetoxyl groups tion. These results imply that the poly(vinyl alcohol) crystal has were measured. The modified BET theory was applied in a high adsorption energy. ᭧ 1998 Academic Press order to analyze the obtained sorption isotherms (7).