4 th Brazilian Conference on Composite Materials. Rio de Janeiro, July 22 nd -25 th , 2018 1 DEVELOPMENT OF PARTIALLY BIODEGRADABLE FOAMS FROM PP/HMSPP BLENDS WITH NATURAL AND SYNTHETIC POLYMERS Cardoso, E. C. L. (1) , Scagliusi, S. R. 1 , Parra, D.F. 1 and Lugão, A. B. 1 (1) Center for Chemical and Environmental Technology (CQMA), Nuclear and Energy Research Institute, S. Paulo, Brazil https://doi.org/10.21452/bccm4.2018.13.05 Abstract Polymers are used in various applications and in different industrial areas providing enormous quantities of wastes in environment. Among diverse components of residues in landfills are polymeric materials, including Polypropylene, which contribute with 20 to 30 % of total volume of solid residues. As polymeric materials are immune to microbial degradation, they remain in soil and in landfills as a semi-permanent residue. Environmental concerning in litter reduction is being directed to renewable polymers development for manufacturing of polymeric foams. Foamed polymers are considered future materials, with a wide range of applications; high density structural foams are specially used in civil construction, in replacement of metals, woods and concrete with a final purpose of reducing materials costs. At present development, it was possible the incorporation of PP/HMSPP polymeric matrix blends with sugarcane bagasse and PHB in structural foams production. Gamma radiation degradation, at 50, 100, 150, 200 and 500 kGy showed effective for biodegradability induction. Irradiated bagasse blends suffered surface erosion, in favor of water uptake and consequently, a higher biodegradation in bulk structure. Keywords: PP/HMSPP; PHB; sugarcane bagasse; gamma-radiation; biodegradability 1. INTRODUCTION Foamed polymers are future materials, with a comprehensive application field; they are especially used to improve structures appearance or to reduce costs of involved material, besides their applications in construction market. In summary, structural foams (high density foams with density higher than 320 kg/m 3 ), have major applications in automotive industry, in heavy equipment and in civil construction, where they can replace wood, metals and even concrete. Most of thermoplastics can be extruded in order to obtain structural foams and commercial activities are concentrated in thermoplastic of lower cost, as Polypropylene (PP) [1]. PP suffers simultaneously chain-scission and crosslinking, when subjected to ionizing radiation; both chemical phenomena are able to induce changes capable to enhance its use in various applications and in different