New chitin-based polymer hybrids, 4: soil burial degradation behavior of poly(vinyl alcohol)/chitin derivative miscible blends

Abstract

Soil burial degradation behavior of miscible blend systems of poly(vinyl alcohol) (PVA)/partially deacetylated chitin (1), PVA/chitin-graft-poly(2-methyl-2-oxazoline) (2), and PVA/chitin-graft-poly(2-ethyl-2-oxazoline) (3) was investigated in comparison with the case of a pure PVA film. The degradation of the blend films was followed by the weight changes, scanning electron microscopic observation, Fourier transform infrared spectroscopy, 1 H-NMR, and size exclusion chromatography analyses. The rate of weight decrease in these PVA/chitin derivative hybrids was higher than that of control PVA in the soil burial test. Fourier transform infrared spectra of the recovered samples of the blends showed an apparent increase of the absorption intensity due to ␤-diketone structure in PVA, which reflects the progress of biodegradation of PVA by PVA-oxidizing enzymes. Scanning electron microscopic observation revealed that these blend films were degraded by bacteria and actinomycetes. The triad tacticity and number-average molecular weight of PVA in the hybrids after soil burial determined by 1 H-NMR and size exclusion chromatography, respectively, were almost the same as those before soil burial. These results suggested that enzymatic degradation of the hybrid films occurred mainly on the surface and that degradation of the PVA-based samples in the soil was accelerated by blending the chitin derivatives.

Selected properties of pH‐sensitive, biodegradable chitosan–poly(vinyl alcohol) hydrogel

“…Poly(vinyl alcohol) is one of the more widely used polymers because of its excellent mechanical properties. It is also biodegradable under suitable conditions 4. Commercial PVA is a mixture of different types of steroregular PVA structures (isotactic, syndiotactic, and atactic).…”

Modification of poly(vinyl alcohol) with lactose and calcium lactate: potential filler from dairy industry

“…2 One of the possibilities to solve these problems is the alteration of PVA properties by a suitable modifier, which can be poly(3-hydroxybutyrate), chitin derivatives, hydrolysed collagen, starch and others. [3][4][5][6] Some papers also show the use of waste materials, which is advantageous for environmental reasons. 5,7,8 In this context, modification with lactose and calcium lactate comes forward because both of these compounds can be obtained from the waste byproducts generated by dairy industry.…”

Biodegradable polymers based on renewable resources. V. Synthesis and biodegradation behavior of poly(ester amide)s composed of 1,4:3,6‐dianhydro‐D‐glucitol, α‐amino acid, and aliphatic dicarboxylic acid units

“…In concert with the depletion of oil resources, increasingly greater attention has been directed to effective utilization of plant‐biomass as alternative, renewable resources that can be steadily supplied and used for polymer syntheses. We also have been investigating polymer syntheses from renewable resources22–24 and biopolymer–synthetic polymer hybrids as well 25–28. In particular, we have been engaged in biodegradable polymer syntheses using three stereoisomeric 1,4:3,6‐dianhydrohexitols, that is, 1,4:3,6‐dianhydro‐ D ‐glucitol ( 1 ), 1,4:3,6‐dianhydro‐ D ‐mannitol ( 2 ), and 1,4:3,6‐dianhydro‐ L ‐iditol ( 3 ) 29–33.…”