Keynote Speaker
Prof. Dr. Sahrim Ahmad
School of Applied PhysicsFaculty of Science And Technology
Universiti Kebangsaan Malaysia
43650 Ukm, Bangi Selangor, Malaysia
Speech Title: Electrical and mechanical properties of modified polylactic nanocomposites for advanced applications
Abstract: Although poly(lactic acid) (PLA) is among widely used biodegradable polymers, it has limited applications due to its inherent brittleness, low elongation at break and toughness. Blending with natural rubber (NR) and epoxidised natural rubber (ENR) seems to be a promising alternative, as both materials are derived from renewable resources. In this work, we report a melt blend of poly(lactic acid)(PLA)/epoxidized natural rubber (ENR) with liquid natural rubber (LNR). The LNR was synthesized by a photochemical degradation technique and used as a compatibilizer in the PLA/rubber binary blending systems . In this study also we were prepared various types of nanocomposites by incorporating different types of nanoparticles in the modified PLA matrix such as graphene nanoplatelets (GNP), magnetite and cellulose nanofibers. Natural rubber was melt blended with poly(lactic acid) in an internal mixer. Liquid epoxidised natural rubber (LENR) was used as a compatibiliser in the binary blending system of thermoplastic natural rubber (TPNR). It was found that the addition of LENR compatibiliser improved the stress at break and Young’s modulus in the blend system of 40/60 PLA/rubber compositions. The increase in stress at break and Young’s modulus were associated with the ability of LENR to compatibilise the PLA/NR binary blends . The PLA/LNR/PANI nanocomposites filled with GNP was prepared via melt blending method using an internal mixer. The contents of the GNP fillers were varied from 0.2 weight% (wt%) to 1.0 wt%. The findings showed positive properties improvement with the addition of GNP at low content in the polymer matrix. The results of tensile, impact and thermal stability properties indicated the optimum content was achieved at 0.4 wt%. Based on the flexural and the TCA tests, the optimum improvement was obtained at 0.6 wt% and 0.8 wt% of GNP, respectively. TEM micrograph has shown good dispersion of GNP in the PLA/NR blend. Electrical properties showed an improvement with the present of treated-GNP and the percolation threshold occurs at low treated and untreated GNP content .
Keywords: Nanocomposites, polylactic acid, epoxidised natural rubber, mechanical properties, melt blending, renewable resources.
Biography: Professor Dr Sahrim Ahmad obtained his PhD from University of Loughborough, United Kingdom in 1988. He is an expert in the field of magnetic, nanocomposites and advanced materials. He has completed more than 50 research projects and consultancy work as a leader and co-researcher. His work on novel radar absorbing materials (RAM) subjected to transverse electromagnetic (TEM) has been successfully developed. His team managed to produce products that offered proper characteristics for handling, flexibility and lightweight, meeting requirement for various applications. He has published more than 200 papers in various journals and supervised more than 50 PhD students. Dr Sahrim was former Dean of Faculty Science of Technology for more 7 years and Editor In Chief of Journal Sains Malaysiana (ISI/WOS} . He has won many inovation awards at international level.