Study on Various Compositions of Polyvinyl Alcohol and Starch Blends by Cross-Linking with Glyoxal

Abstract

The aim of this study is to analyze the various compositions of polyvinyl alcohol (PVA) and starch blends. The blends have been cross-linked with glyoxal to enhance its properties. The hydroxyl groups of PVA and starch react with glyoxal via formation of acetal bonds; hence crosslinking could take place. The cross-linking of glyoxal is observed in various analytical methods such as DSC and FTIR. The cross-linked blends showed better thermal and mechanical properties. Viscosity, tensile shear strength, pencil hardness and ultimate stress were evaluated to estimate the changes due to cross-linking. It was observed that the cross-linking is directly proportional to starch, since the starch hydroxyl groups are easily accessible for reacting. The cross-linked blend showed better cohesion between its chains, thereby increasing glass transition temperature. It was reflected in the subsequent increase in tensile strength properties.

Assisted Compatibility, and Balanced Regulation of the Mechanical, Thermal, and Antioxidant Activity of Polyvinyl Alcohol-Chinese Bayberry Tannin Extract Films Using Different Di-Aldehydes as Cross-Linkers

“…The formation of covalent bonds generally results in better mechanical performance, water resistance and thermal stability of PVA blends. For example, glyoxal cross-linked PVA/starch blends [33], glutaraldehyde cross-linked PVA/cellulose films [9], and glutaraldehyde cross-linked PVA/chitosan blends [34]. Except for the mentioned low molecular weight dialdehydes, dialdehyde starch is a promising polymeric dialdehydes due to its low toxicity.…”

Cellulose Stabilized Polyvinyl Acetate Emulsion: Review

“…Release of unreacted formaldehyde in bonded wood occurs under hot and humid conditions [4] [5]. Various biomasses have been exploited as green adhesives including cellulose [6]- [12], starch [13] [14] [15], lignin [16] [17] [18], tannin [19] [20] [21], natural rubber latex [22] [23], soy protein [24] [25] [26] and vegetable oils [27]. Researchers' acceptance of these biomaterials is due to the added advantages of renewability, eco friendliness, and very low emission of volatile organic solvents in adhesives [28] [29].…”