Functionalization, Compatibilization and Properties of Polyolefin Composites with Natural Fibers

Abstract

Abstract:The article is focused on analyzing the effect of functionalization and reactive processing on the morphological, thermal, rheological and mechanical properties of composites of isotactic polypropylene (PP), polystyrene (PS), poly(ethylene-vinyl acetate) (EVA), with cellulose fibers, hemp or oat as natural fillers. Both polymers and fibers were modified with bi-functional monomers (glycidyl methacrylate, GMA; maleic anhydride, MA) capable of facilitating chemical reactions between the components during melt mixing. Polyolefin copolymers containing reactive groups (PP-g-GMA, SEBS-g-MA, PS-co-MA, etc.) were used as compatibilizers. Optical and SEM microscopy, FTIR, RX, DSC, TGA, DMTA, rheological and mechanical tests were employed for the composites characterization. The properties of binary and ternary systems have been analyzed as a function of both fiber and compatibilizer content. All compatibilized systems showed enhanced fiber dispersion and interfacial adhesion. The phase behavior and the thermal stability of the composites were affected by the chemical modification of the fibers. Marked changes in the overall crystallization processes and crystal morphology of PP composites were observed owing to the nucleating effect of the fibers. The tensile mechanical behavior of the compatibilized composites generally resulted in a higher stiffness, depending on the fiber amount and the structure and concentration of compatibilizer. OPEN ACCESSPolymers 2010, 2 555

Studies on gamma irradiated rubber materials

“…This leads to poor interface between organic filler and hydrophobic matrix of elastomer. In order to improve the interfacial interactions between rubber and organic filler, addition of compatibilizers is required [10], [11] in the case of maleated natural rubber (NR-g-AM). The compatibilizing agent was obtained by roll mixing NR with 5 phr (parts per 100 parts of rubber) of maleic anhydride for synthesis (produced by Merck KGaA, Germany, melting point 52°C) and 0,75 phr of Perkadox 40.…”

Utilization of banana stalk fiber as reinforcement in low density polyethylene composite

“…The fiber was also used with other fibers such as jute, hemp and glass, sisal and flax [14][15][16][17]. However, the weak compatibility between fibers and polymer matrix due to their poor wettability and weak interfacial bonding, the low dispersion degree of the fibers, as well as its poor moisture resistance, generally leads to low performance materials, limiting their use [18]. Size, geometry and dispersion of filler particles in the matrix are other factors which can largely affect the composite properties.…”

“…Size, geometry and dispersion of filler particles in the matrix are other factors which can largely affect the composite properties. Surface modification of the fibers and/or polymer functionalization, as well as addition of compatibilizers is required in order to improve the interfacial interactions between hydrophobic polymer and hydrophilic fibers [18]. Therefore, to improve the fiber-matrix adhesion, a pretreatment of the fiber surface or the incorporation of surface modifier during processing is required.…”

Effect of Alkaline Treatment on the Properties of Oil Palm Empty Fruit Bunch Fiber-reinforced Polypropylene Composite

“…The use of natural fibers for the reinforcement of composites has become a popular research topic due to natural fibers' availability and sustainability. Natural fiber has several advantageous properties such as good strength, low density, biodegradability and low cost of production (Ayrilmis et al, 2011;Pracella et al, 2010). Moreover, natural fiber-reinforced composites have a lower density than synthetic fiber-reinforced composites, which ensures the production of lighter composites (Akil et al, 2011;Leao et al, 2010).…”