COMPOSTABLE POLYMER COMPOSITE WITH ADJUSTABLE SERVICE LIFE Russian patent published in 2023 - IPC C08L29/04 C08K5/05 C08K7/02 

FIELD: polymer materials.

SUBSTANCE: invention is related to technologies for creating biodegradable (compostable) polymer materials, in particular to composites based on water-soluble thermoplastics filled with polysaccharides, and can be used to produce materials and products from them that can undergo accelerated biodegradation, including composting. A compostable polymer composite with an adjustable service life contains polyvinyl alcohol and cellulose; PVA with varying contents of vinyl acetate groups in the ranges of 0-10% and 15-25% is used as a polymer matrix, which ensures regulation of the degradation period of the composite under natural environmental conditions from 2 to 12 months, microcellulose in form of fibres with a particle size of 5-100 microns is used as a filler, which provides the effect of a reinforcing filler; glycerine is used as a plasticizer. The composite is produced using liquid-phase technology by direct combination of a 5% solution of PVA plasticized with glycerine and microcellulose powder, followed by dehydration and moulding of the finished product of a given shape with the following ratio of components in the dehydrated composite, wt.%: PVA 60-20, microcellulose 30-70, glycerine 5-15.

EFFECT: development of a compostable polymer composite with an adjustable service life based on polyvinyl alcohol with varying degrees of hydrolysis, which makes it possible to regulate the timing of its destruction under environmental conditions, highly filled with microcellulose in form of fibres with sizes of 5-100 microns, which helps to increase the strength properties of the composite and preserve shape and physical and mechanical properties in conditions of high humidity due to the effect of the reinforcing filler.

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