2009 International Nuclear Atlantic Conference - INAC 2009 Rio de Janeiro,RJ, Brazil, September27 to October 2, 2009 ASSOCIA˙ˆO BRASILEIRA DE ENERGIA NUCLEAR - ABEN ISBN: 978-85-99141-03-8 EFFECT OF IONIZING RADIATION ON NANOCOMPOSITES OF HIGH DENSITY POLYETHYLENE WITH PSEUDOBOEHMITE OBTAINED BY SOL-GEL PROCESS Leila F. Miranda 1 , Antnio H. Munhoz Jœnior 1 , Mauro C. Terence 1 , Leonardo G. de Andrade e Silva 2 and Alexandre P. Alves 1 1 Escola de Engenharia - Curso de Engenharia de Materiais Universidade Presbiteriana Mackenzie Rua da Consolaªo, 896 01302-907 Sªo Paulo, SP lfmiranda@sti.com.br 2 Instituto de Pesquisas EnergØticas e Nucleares (IPEN / CNEN - SP) Av. Professor Lineu Prestes 2242 05508-000 Sªo Paulo, SP lgasilva@ipen.br ABSTRACT Nanocomposites are polymeric hybrid materials where inorganic substances of nanometric dimensions are dispersed in a polymeric matrix. The fillers present area of raised surface, promoting better dispersion in the polymeric matrix and therefore an improvement of the physical properties of the composite that depends on the homogeneity of the material. The nanocomposites preparation with polymeric matrix allows in many cases to find a relation enters a low cost, due to the use of minor amount of filler, and a raised performance level. Nanocomposites were obtained with pseudoboehmite synthesized by sol-gel process and high density polyethylene with different concentrations of pseudoboehmite. The aim of this work was to study the effects of ionizing radiation on the properties of the nanocomposites obtained. The nanocomposites were prepared by melt intercalation technique and subsequently, the samples were molded by injection, irradiated and submitted to thermal and mechanical tests. The mechanical properties (impact strength and tensile strength), temperature of thermal distortion (HDT) and Vicat softening temperature of the non irradiated and irradiated nanocomposites were determined. The irradiation doses were of 30, 50 and 100kGy in a gamma cell. The results showed an increase in the values of tensile strength; a decrease in the impact strength and an increase in the temperature of thermal distortion (HDT) evidencing the interaction of nanofiller with the polymeric matrix. 1. INTRODUCTION Polymeric nanocomposites are a hybrid material where inorganic substances with nanometric dimensions are dispersed in a polymeric matrix [1, 2]. Actually, polymeric nanocomposites have attracted great industrial and scientific interest due to attainment of materials with better mechanical, barrier and flammability properties. These improvements can be obtained when small concentrations of the inorganic filler are added to the polymeric matrix and its layers are exfoliated and well dispersed [1, 3]. Modified organically clays can be efficiently exfoliated in polar polymers using adequate conditions of processing [3, 4]. As the fillers present nanometric dimensions, its surface area is very high promoting better interaction with the polymeric matrix and improvement of the composite physical properties