Natural Fibres/Polyolefins Composites (I) UV and Electron Beam Irradiation

The goal of the present work is to obtain and characterise new composites based on polyolefins, such as LDPE, HDPE and PP, as matrix and cellulose fibres as fillers. Three types of cellulose based fibres were used, namely cellulose-chitin antimicrobial nano-fibres (Chitcel) and two types of Banana tree (Musa sp.) fibres. The banana tree fibres were used as such and treated with NaOH in order to improve their interaction with the matrix. Their resistance to electron beam (EB) and UV irradiation was monitored by altering their surface characteristics through ATR-FTIR and contact angle measurements, as well as their bulk properties, such as thermal and mechanical characteristics determined by DSC and tensile strength measurements, respectively. The polyolefin composites showed higher tensile strength and higher surface hydrophilicity after UV and electron beam irradiation as compared to the irradiated polyolefins. New carbonyl, hydroxyl and ether groups were identified in the irradiated composites, which contributed to the improvement of POs-fibres adhesion. A stabilizing effect of cellulose fibres on the tensile strength of UV irradiated composites by comparing to those of irradiated neat matrix has been noted.