Effects of Dynamic Vulcanization on Tensile, Morphological, and Swelling Properties of Poly(vinyl chloride) (PVC)/Epoxidized Natural Rubber (ENR)/(Kenaf Core Powder) Composites Hanafi Ismail, Rohani Binti Abdul Majid, Razaina Mat Taib School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia (USM), Nibong Tebal, 14300 Nibong Tebal, Penang, Malaysia The effects of dynamic vulcanization on properties of poly(vinyl chloride) (PVC)/epoxidized natural rubber (ENR)/(kenaf core powder) composite were studied. Tensile properties indicated that the strength, elonga- tion at break, and Young’s modulus of the composites exhibited an increase for samples with dynamic vul- canization. Morphological analysis using scanning electron microscopy showed the interaction between ENR and PVC. There was no bonding between kenaf core powder and the PVC/ENR matrix owing to the dif- ferent polarity of both components. Filler agglomerates increased, which leads to an increase of filler-filler interaction and poor dispersion. Furthermore, swelling index indicated that the composite with dynamic vul- canization shows lower absorption of tolune compared with composites without dynamic vulcanization. J. VINYL ADDIT. TECHNOL., 00:000–000, 2014. V C 2014 Society of Plastics Engineers INTRODUCTION Blending of thermoplastic and elastomer has become a technological interest for use as thermoplastic elastomer (TPE). TPE can have properties of thermoplastic material, such as high mechanical properties, high ozone resistance, and high aging resistance [1]. In addition, TPE can main- tain the elastomeric properties, such as the elasticity, high oil resistance, and low gas permeability [1]. TPE offers attractive alternatives in a wide range of applications owing to its unique properties and processing methods. There are many studies in TPE material development beginning decades ago, including polypropylene/(nitrile rubber), poly(vinyl chloride) (PVC)/NBR, polypropylene/ (ethylene propylene diene monomer), and PVC/epoxi- dized natural rubber (ENR) [2–6]. The development of research in PVC/ENR blends has been widely explored [7]. The compatibility between these two materials had made the blends a good option to reduce the consumption of PVC and ENR and at the same time enhance proper- ties of the materials. PVC itself has good mechanical strength and generally is a rigid plastic without the addi- tion of plasticizer. It is inherently ductile because of the polarity and low-temperature molecular relaxation. How- ever, it is brittle at high deformation rate, and under con- centrated stress, and the PVC is known as a notch- sensitive polymer [8]. Some appealing properties can be improved with the addition of ENR rubber. Recently, the use of natural fiber had attracted atten- tion owing to its renewability, availability, low cost, light weight, and the fact that it is environmentally friendly [9]. Among different natural fibers, kenaf fiber offers many potential properties in specific application, such as low density, high specific mechanical properties, and the ability to absorb nitrogen and phosphorous from the soil [10]. In this research article, the use of kenaf core powder in the blend of PVC/ENR was studied. The incorporation of natural fiber into the blend of PVC/ENR might also contribute to the environmental use and reduce the con- sumption of plastic and rubber material. Furthermore, it can maintain the mechanical properties of the composite. There are still few researchers involved in the reinforce- ment of TPE blends. Chantara et al. incorporated the use of oil palm empty fruit bunch into the blend of PVC/ENR and observed the effect of electron beam irradiation toward the composites [11]. In this research study, we focus on the mechanical properties of the TPE composites with and without dynamic vulcanization, and compatibil- ity of the kenaf core powder itself with the matrix of PVC/ENR. EXPERIMENTAL Materials Epoxidized natural rubber (Epoxyrene 50) with a 50% epoxidization level and with a K value of 66, M n 5 66,000; grade MH66, 6519, was purchased from Industrial Resin (M) Ltd. Diocthyl-phthalate (DOP), Correspondence to: Hanafi Ismail; e-mail: ihanafi@usm.my DOI 10.1002/vnl.21401 Published online in Wiley Online Library (wileyonlinelibrary.com). V C 2014 Society of Plastics Engineers JOURNAL OF VINYL & ADDITIVE TECHNOLOGY—2014