Polymer Composites from Poly(vinyl alcohol), Horn Meal and Crude Glycerol for Mulching Coatings

Abstract

In this article we report on the preparation of polymer composites from poly(vinyl alcohol), cattle horn meal and glycerol, which is the byproduct of biodiesel production. The effect of the amount of glycerol as well as of the particle size of horn meal on the mechanical, sorption properties, water vapour permeability, content of water soluble nitrogen and carbon in the films of the composites was studied. The composites were used for the preparation of coatings for the mulching of plants cultivated in pots. The liquid mulching composition was spread out on the surface of the growing substrate. After evaporation of water the polymer coatings, acting as a mulch films, were obtained. It was established that the proposed mulch films retain moisture in the pots and stimulate microbial activity of the soil. The rate of evaporation of water from the substrate coated with the mulch films was by 26–33 % lower than that from the unmulched substrate. The number of the fungal colony forming units in the substrates depended on the particle size of the horn meal in the mulch composite and was by 1.7 9 104–4.1 9 104 times higher compared with that found in the unmulched substrate. The composites were used for the mulching of the tomato sprouts cultivated in pots. It was established that the proposed mulch films stimulate growth of plants.