Prediction of plugging effect of biopolymers using their glass transition temperatures

In this paper, it was demonstrated that the two main transition temperatures, i.e., the glass-rubber transition temperature (Tg) and the crystalline melting temperature (Tm) of biopolymers, can be correlated with their chemical structure by means of the van Krevelenʹs method based on additive group-contributions. Five different biopolymers, namely polyhydroxybutyrate (PHB), chitosan, polyglutamic acid (PGA), guar gum and xanthan, were studied. The transition temperatures of these five biopolymers were predicted using the above method. In this paper, the ratio, Tg/Tm, was calculated to be 0.62, which is close to the value first reported to be 0.66. The data calculated were in agreement with the experimental data of other laboratories. shown that PHB had the lowest Tg and Tm, and xanthan had the highest Tg and Tm. Also, from a previous study, PHB had the highest permeability reduction factor (i.e., best plugging effect), and xanthan had the lowest permeability reduction factor (i.e., worst plugging effect). This means that at low Tg and Tm the biopolymer has a glassy behavior, which makes it a good plugging agent (in this case PHB).