Interactions of Hydrophilic Plasticizer Molecules with Amorphous Starch Biopolymer—An Investigation into the Glass Transition and the Water Activity Behavior
MetadataShow full item record
In this article, we demonstrated that within a hydrophilic biopolymer–plasticizer system, the molecular ‘‘activity’’ of the plasticizer also influenced the extent of these interactions. We demonstrated through an analysis of crystallinity and calorimetry results that the equilibrium moisture content within the starch matrix can preferentially interact with the hydrophilic plasticizers and modify the polymer recrystallization process to an extent that the commonly acknowledged relationship between the crystallinity and the glass transition behavior is disrupted. Two plasticizers, glycerol (three AOH groups) and xylitol (five AOH groups), were selected. The water sorption isotherm of polymer samples with 5–20 wt % (dry basis) plasticizers were examined across a water activity range from ~0.11 to ~0.95 and using Guggenheim-Anderson-de Boer analysis, we compared the molar sorption enthalpies of various starch–plasticizer mixtures. Finally, the competitive plasticization between water and plasticizer molecules at different water activities was also discussed using known glass transition models. The analyses validated the antiplasticization limit for glycerol to be ~10–15 wt %, but for xylitol, its anti-plasticization behavior did not manifest till 20 wt %.
Showing items related by title, author, creator and subject.
Glass-transition behaviour of plasticized starch biopolymer system - A modified Gordon-Taylor approachChaudhary, Deeptangshu; Adhikari, B.; Kasapis, S. (2011)Two plasticizers namely, glycerol and xylitol, based on their similar molecular size (6.3 A) but different molecular weights (Glycerol-92; Xylitol-152) were selected for studying the glass-transition behaviour (rubber ...
Synergistic interactions of plasticizers and nanoclays in hydrophilic starch based bionanocompositesLiu, HuiHua (2011)Depletion of non-renewable resources and exorbitant levels of carbon dioxide emissions have questioned the further usage of traditional plastics. The imbalance in global sustainability has necessitated the development and ...
Kazemian, Sina ; Ghareh, S. (2016)Plastic concrete is a suitable material for building earth dam cut off due to low permeability, high deformability and enough strength to withstand applied stresses. Due to the lack of a specified standard for plastic ...