%0 Journal Article
%T SOLVATION EFFECT OF POLY(VINYL ALCOHOL) IN AQUEOUS SOLUTION via REPEATING FREEZING-THAWING CYCLES<br>聚乙烯醇水溶液反复冷冻过程中的溶剂化效应
%A LI Wenbo
%A XUE Feng
%A CHENG Rongshi
%A <br>李文波
%A 薛锋
%A 程镕时
%J 高分子学报
%D 2008
%I 
%X The article is devoted to the study on solvation effect of poly(vinyl alcohol) (PVA) in aqueous solution via repeating freezing-thawing cycles using differential scanning calorimetry (DSC) technique.A straightforward method for determination of the hydration number,a parameter characterizing the extent of solvation effect,of polymers in aqueous solutions based on ice-melting technique of DSC is proposed.The simple yet precise method has been applied to determine the hydration number of PVA in aqueous solution covering a wide range of concentrations,from 0.005 to 0.3 g/g.The results indicate that the melting enthalpies and hydration numbers of PVA aqueous solutions differentiate greatly at different concentration regimes,i.e.dilute,semi-dilute,concentrated concentration region,which is attributed to the differences of intra-and inter-chain entanglements in their influence on the participation of solvent molecules in the solvation-desolvation process.The inter-chain entanglement points increase with increasing freezing cycles,which leads to part of solvent molecules entrapped in loops produced by inter-chain contact and forming a portion of polymer chain.Apparent change of solvation effect is a complex influence of desolvation and entrapped solvents.
%K Poly(vinyl alcohol)
%K Differential scanning calorimetry
%K Solvation
%K Inter-chain entanglement<br>聚乙烯醇
%K 示差扫描量热仪
%K 溶剂化
%K 链间缠结
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=6E709DC38FA1D09A4B578DD0906875B5B44D4D294832BB8E&cid=6579068328FE643F&jid=15971983683C7643EE80F1CE621DEB60&aid=9C155529617A8391E8B84B0141403363&yid=67289AFF6305E306&iid=59906B3B2830C2C5&sid=9978E8308B7F7CE6&eid=9E33BE6F309BC209&journal_id=1000-3304&journal_name=高分子学报&referenced_num=0&reference_num=11