Effect of gelatinization and additives on morphology and thermal behavior of corn starch/PVA blend films

• Published in: Carbohydrate polymers Vol. 90; no. 4; pp. 1595 - 1600
• Main Authors: Luo, Xuegang, Li, Jiwei, Lin, Xiaoyan
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 06.11.2012; Elsevier
• Subjects: Additive; additives; Applied sciences; Biocompatible Materials - chemistry; Calorimetry, Differential Scanning; corn starch; Exact sciences and technology; Gelatin - chemistry; Gelatinization; glycerol; Glycerol - chemistry; Glycerol - pharmacology; Hydrogen Bonding; melting point; Microscopy, Electron, Scanning; Morphology; Natural polymers; Organic polymers; Physicochemistry of polymers; Polyvinyl alcohol; Polyvinyl Alcohol - chemistry; Properties and characterization; Solvents - chemistry; Solvents - pharmacology; Starch; Starch - chemistry; Starch and polysaccharides; Temperature; Thermal and thermodynamic properties; Thermal behavior; thermal properties; Thermogravimetry; urea; Urea - chemistry; Urea - pharmacology; Zea mays; Additive; Polyvinyl alcohol; Gelatinization; Starch; Morphology; Thermal behavior; Polymer blends; Glycerol; Experimental study; Corn starch; Heterogeneous mixture; Thermal stability; Transformation temperature; Intermolecular interaction; Polyvinylalcohol; Urea; Heat of transformation; Plasticizer; Oside polymer; Hydrogen bond
• ISSN: 0144-8617; 1879-1344; 1879-1344
• DOI: 10.1016/j.carbpol.2012.07.036

► Starch/polyvinyl alcohol blend films were prepared by the solution casting method. ► The effects of gelatinization on the properties of the films were investigated. ► The effects of additives on the properties of the films were investigated. ► A conceptual model of hydrogen bonding interactions was established. The blend films of ungelatinized and gelatinized starch/polyvinyl alcohol (PVA) were prepared with a solution casting method by the introduction of additives (glycerol/urea) or not. The phase morphologies and thermal behaviors of the blends were carefully analyzed. A droplet phase was observed in the blends containing ungelatinized starch and a laminated phase was observed in the blends containing gelatinized starch. For both ungelatinized and gelatinized starch/PVA blends, the melting temperature (Tm) (210–230°C) of PVA was detected, and the Tm of gelatinized starch/PVA blends was higher than that of the ungelatinized starch/PVA blends. Blend films containing 16.8wt% of glycerol or urea exhibited a decreased Tm. The introduction of additives (glycerol or urea) reduced the decomposition onset temperature of the blend films. These various morphologies and thermal behaviors could be attributed to the different hydrogen bonding interaction characteristics between starch and polyvinyl alcohol at different conditions.