A Method of Calculating Gelation Parameters in Aqueous Solutions of biopolymers

摘要

The proposed set of equations markes it possible to determien the temperature T_gel and concentration P_gel fo the transition of a biopolymer solution into the gel-like state(the sol-gel transition) and the gel melting temperatureT_m(the gel-sol transition).The resultant expessions for T_gel,P_gel,and T_m depend on constants that are universal for aqueous solutions of biopolymers,melting points of biopolymers T_mp,and their glass transition temperatures T_g.One can thus establish how the chemical structure of a biopolymer affects its T_gel,P_gel,and T_m values.The relationships between the gelation temperatures T_gel and gel melting temperatures T_m and the biopolymer concentration P at P>P_gel are found.The constants of the equations are derived form the experimental data for poly(vinyl alcohol) and starch.The calculated results agree well with the experimental data.Within the framework of the proposed approach,the concentration limits of the plasticizin gaction of water are also determiend and the melting tmeperature of gels of biopolymer mixtures are estimated.