Electron beam (EB) irradiation technique was introduced to modify the crystallization and oxygen (O2) barrier properties of high density-polyethylene (HDPE)/ethylene propylene diene monomer (EPDM) matrix and HDPE/EPDM filled withorganophilic montmorillonite (OMMT). The absorbed dose for EB-irradiation was fixed at 100？kGy. HDPE/EPDM matrix and HDPE/EPDM filled with OMMT at 4？vol% loading were prepared via melt intercalation method. It was found that the barrier resistance of HDPE/EPDM filled withOMMT against oxygen (O2) transmission was significantly enhanced by EB-irradiation absorbed dose of 100？kGy as compared to the control system. The crystallization temperature, , and melting temperature, , were also improved with the addition of OMMT along with the aids of EB-irradiation technique. Field emission scanning electron microscope (FESEM) revealed that the stacking condition of OMMT particles was greatly reduced by EB-irradiation treatment as evidenced by finer surface and less formation of voids. 1. Introduction For many years, increasing interest has been devoted to polymeric alloys because blending is an important route for the preparation of materials with synergistic and modified properties [1, 2]. Polymer blends play an important role in achieving the required and desired properties that cannot be gained from a polymer alone. However, such a generalized concept should be more clearly defined to include the scale of the reinforcements since systems can be reinforced chemically at both microscopic and nanoscopic levels. Because of this reason, nanosized filler is introduced in order to develop nanocomposite with desired properties. The nanosized filler is based on the use of a low concentration of expandable smectite clays, such as organomontmorillonite (OMMT), in the matrix. Multifunctional benefits such as mechanical performance, oxygen permeability resistance and flame-retardant characteristics are obtained simultaneously. Different types of filler or reinforcement can be incorporated into polymer blending system, but the selection of the silicate layer is more preferable. This is due to the fact that use of traditional filler such as talc and mica increases the mechanical properties and yet additionally increases weight which is typically considered a negative factor in designing a material. Because of this reason, clay silicate as an emerging class of filler which requires less content to achieve similar or improved mechanical and thermal properties as well as barrier property has been used in this research work [3, 4]. Small amounts of
References
[1]
LI. H. Lin, H. J. Liu, and N. K. Yu, “Morphology and thermal properties of poly(L-lactic acid)/ organoclay nanocomposites,” Journal of Applied Polymer Science, vol. 106, no. 1, pp. 260–266, 2007.
[2]
C. Li and T. W. Chou, “Multiscale modeling of compressive behavior of carbon nanotube/polymer composites,” Composites Science and Technology, vol. 66, no. 14, pp. 2409–2414, 2006.
[3]
H. R. Dennis, D. L. Hunter, D. Chang et al., “Effect of melt processing conditions on the extent of exfoliation in organoclay-based nanocomposites,” Polymer, vol. 42, no. 23, pp. 9513–9522, 2001.
[4]
D. F. Eckel, M. P. Balogh, P. D. Fasulo, and W. R. Rodgers, “Assessing organo-clay dispersion in polymer nanocomposites,” Journal of Applied Polymer Science, vol. 93, no. 3, pp. 1110–1117, 2004.
[5]
H. F. Guo, S. Packirisamy, N. V. Gvozdic, and D. J. Meier, “Prediction and manipulation of the phase morphologies of multiphase polymer blends: 1. Ternary systems,” Polymer, vol. 38, no. 4, pp. 785–794, 1997.
[6]
B. Croonenborghs, M. A. Smith, and P. Strain, “X-ray versus gamma irradiation effects on polymers,” Radiation Physics and Chemistry, vol. 76, no. 11-12, pp. 1676–1678, 2007.
[7]
K. A. Dubey, Y. K. Bhardwaj, C. V. Chaudri, and S. Sabharwal, “Role of blend morphology in the radiation processing of SBR-EPDM blends,” BARC Newsletter, vol. 273, pp. 92–93, 2005.
[8]
M. F. Vallat, S. Marouani, S. Perraud, and N. M. Patlan, “Crosslinked blends and coextruded films by electron beam,” Nuclear Instruments and Methods in Physics Research B, vol. 236, no. 1-4, pp. 141–144, 2005.
[9]
T. D. Matthew, “Innovative barrier technologies boost viability of pet beer bottles,” Modern Plastics, pp. 26–27, 2000.
[10]
P. Demetrakakes, “Nanocomposites raise barriers, but also face them: clay-based additives increase the barrier qualities of plastics, but obstacles to commercialization must be overcome,” Nanocomposite Materials. In press.
[11]
Y. Lei, Q. Wu, and C. M. Clemons, “Preparation and properties of recycled HDPE/clay hybrids,” Journal of Applied Polymer Science, vol. 103, no. 5, pp. 3056–3063, 2007.
[12]
A. Durmu？, M. Woo, A. Ka？g？z, C. W. Macosko, and M. Tsapatsis, “Intercalated linear low density polyethylene (LLDPE)/clay nanocomposites prepared with oxidized polyethylene as a new type compatibilizer: structural, mechanical and barrier properties,” European Polymer Journal, vol. 43, no. 9, pp. 3737–3749, 2007.
[13]
J. Bandyopadhyay, S. S. Ray, and M. Bousmina, “Thermal and thermo-mechanical properties of poly(ethylene terephthalate) nanocomposites,” Journal of Industrial and Engineering Chemistry, vol. 13, no. 4, pp. 614–623, 2007.
[14]
J. W. Lim, A. Hassan, A. R. Rahmat, and M. U. Wahit, “Mechanical behaviour and fracture toughness evaluation of rubber toughened polypropylene nanocomposites,” Plastics, Rubber and Composites, vol. 35, no. 1, pp. 37–46, 2006.
[15]
T. Y. Tsai, “Templated synthesis of nanoparticles, nanoporous materials and nanowires,” Chemical Information Monthly, vol. 14, no. 10, pp. 59–69, 2000.
[16]
G. E. Mingliang and J. Demin, “Preparation and properties of polypropylene/clay nanocomposites using an organoclay modified through solid state method,” Journal of Reinforced Plastics and Composites, vol. 28, no. 5, pp. 228–230, 2009.
[17]
S. Kim and Y. C. Nho, “Effect of radiation on ultra high molecular weight polyethylene (UHMWPE),” International Energy Atomic Agency, vol. 1617, pp. 93–94, 2009.
[18]
S. Barus, M. Zanetti, P. Bracco, S. Musso, A. Chiodoni, and A. Tagliaferro, “Influence of MWCNT morphology on dispersion and thermal properties of polyethylene nanocomposites,” Polymer Degradation and Stability, vol. 95, no. 5, pp. 756–762, 2010.
[19]
Y. C. Nho, S. M. Lee, and H. H. Song, “Modification of microstructures and physical properties of ultra high molecular weight polyethylene by electron beam irradiation,” International Energy Atomic Agency, vol. 1617, pp. 101–103, 2009.
[20]
G. Choudalakis and A. D. Gotsis, “Permeability of polymer/clay nanocomposites: a review,” European Polymer Journal, vol. 45, no. 4, pp. 972–980, 2009.
[21]
H. M. Dahlan, M. D. K. Zaman, and A. Ibrahim, “Liquid natural rubber (LNR) as a compatibiliser in NR/LLDPE blends—II: the effects of electron-beam (EB) irradiation,” Radiation Physics and Chemistry, vol. 64, no. 5-6, pp. 429–436, 2002.
