Biodegradability of PP/HMSPP and natural and synthetic polymers blends in function of gamma irradiation degradation

• Published in: Radiation physics and chemistry (Oxford, England : 1993) England : 1993), 2014-01, Vol.94, p.249-252
• Main Authors: Cardoso, Elisabeth C.L., Scagliusi, Sandra R., Lima, Luis F.C.P., Bueno, Nelson R., Brant, Antonio J.C., Parra, Duclerc F., Lugão, Ademar B.
• Format: Article
• Language: English
• Subjects: Biodegradability; Carbon; Consumption; Degradation; Gamma radiation; Gamma rays; Microorganisms; PHB; PLA; Polymer blends; Polypropylene; Polypropylenes; Sugarcane bagasse
• ISSN: 0969-806X; 1879-0895
• DOI: 10.1016/j.radphyschem.2013.07.017

Polymers are used for numerous applications in different industrial segments, generating enormous quantities of discarding in the environment. Polymeric materials composites account for an estimated from 20 to 30% total volume of solid waste. Polypropylene (PP) undergoes crosslinking and extensive main chain scissions when submitted to ionizing irradiation; as one of the most widely used linear hydrocarbon polymers, PP, made from cheap petrochemical feed stocks, shows easy processing leading it to a comprehensive list of finished products. Consequently, there is accumulation in the environment, at 25 million tons per year rate, since polymeric products are not easily consumed by microorganisms. PP polymers are very bio-resistant due to involvement of only carbon atoms in main chain with no hydrolysable functional group. Several possibilities have been considered to minimize the environmental impact caused by non-degradable plastics, subjecting them to: physical, chemical and biological degradation or combination of all these due to the presence of moisture, air, temperature, light, high energy radiation or microorganisms. There are three main classes of biodegradable polymers: synthetic polymers, natural polymers and blends of polymers in which one or more components are readily consumed by microorganisms. This work aims to biodegradability investigation of a PP/HMSPP (high melt strength polypropylene) blended with sugarcane bagasse, PHB (poly-hydroxy-butyrate) and PLA (poly-lactic acid), both synthetic polymers, at a 10% level, subjected to gamma radiation at 50, 100, 150 and 200kGy doses. Characterization will comprise IR, DSC, TGA, OIT and Laboratory Soil Burial Test (LSBT). •Polymeric materials composites account for an estimated from 20 to 30% total volume of solid waste.•Landfills will not be enough for an estimated accumulation of 25 million tons per year of plastics.•Incorporation of natural/synthetic polymers in PP/HMSPP to reduce litter effects in environment.•Natural/synthetic polymers added to PP/HMSPP at 10% level provided initial biodegradation.•Soil burial and infra-red determination are prevailing biodegradability assessments.