Natural rubber-polystyrene interpenetrating networks. Morphology and mechanical properties
TL;DR: In this paper, a sequential interpenetrating polymer network (IPN) was synthesized using natural rubber and polystyrene as elastomer and plastomer components, respectively.
About: This article is published in European Polymer Journal.The article was published on 1993-01-01. It has received 9 citations till now. The article focuses on the topics: Plastomer & Elastomer.
Citations
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TL;DR: In this paper, a semi-interpenetrating polymer network (semi-IPN) based on epoxidised natural rubber and polyvinyl alcohol containing maleic acid as a crosslinking reagent was synthesized and characterized by FTIR, XRD, SEM, swelling ratio in both distilled water and toluene, and mechanical properties.
58 citations
TL;DR: In this article, the diffusion and transport of inhibitor-free styrene through crosslinked natural rubber (NR) have been studied at various temperatures and the influence of temperature on the sorption and activation energies of sorption have been calculated.
53 citations
TL;DR: In this article, semi-interpenetrating networks (semi-IPNs) were prepared from natural rubber (NR) and polystyrene (PS) by the sequential method.
Abstract: Semi-interpenetrating networks (semi-IPNs) were prepared from natural rubber (NR) and polystyrene (PS) by the sequential method. In these semi-IPNs the NR phase was crosslinked while the PS phase was uncrosslinked. Different initiating systems such as dicumyl peroxide (DCP), benzoyl peroxide (BPO), and the azobisisobutyronitrile (AIBN) system were used for polymerizing the PS phase. The blend ratio was varied by controlling the swelling of NR in the styrene monomer. The mechanical properties of the semi-IPNs, namely, density, tensile strength, tear strength, elongation at break, tension set, tensile set, impact strength, and hardness, were determined. The morphology of different IPNs was studied using scanning electron microscopy. A compact morphology with a homogeneous phase distribution was observed in the semi-IPNs. The properties of the semi-IPN do not change much with the initiating system. However, in most cases, the DCP initiating system showed slightly superior performance. The tensile and tear-strength values of the IPNs were found to increase with increasing plastomer content. The crosslink density of the semi-IPNs also increased with increase in the polystyrene content. The experimental values were compared with theoretical models such as series, parallel, Halpin Tsai, Coran, Takayanaki, Kerner, and Kunori. The tensile and tear-fracture surfaces were examined using a scanning electron microscope. The fracture patterns were correlated with the strength and nature of the failure. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 2327–2344, 2000
24 citations
TL;DR: In this paper, a new blend membrane from chemically modified natural rubber latex (NRL) and polyvinyl alcohol (PVA) was used for release application. But the potential of the membrane for the use in the release application was tested with model organic dyes rhodamine B, methyl orange and fluorescein.
Abstract: Novel blend membranes were prepared from chemically modified natural rubber latex (NRL) and poly(vinyl alcohol) (PVA) for release application. Chemical modification of NRL was done by grafting (dimethylaminoethyl methacrylate) (DMAEMA) onto NR particles by using a redox initiator system viz; cumene hydroperoxide/tetraethylenepentamine (CHP/TEPA), followed by dialysis for purification. The grafting was confirmed by dynamic light scattering (DLS), fourier transform infrared (FT-IR) spectroscopy and nuclear magnetic resonance spectroscopy (NMR). The grafted NRL was subsequently blended with PVA to make uniform membranes by solvent casting at 60 ± 2 °C. The blend membranes were characterised by FT-IR spectroscopy, X-ray diffractometry (XRD) and thermogravimetry (TGA). Moisture uptake, swelling and water contact angle experiments showed an increased hydrophilicity when the PVA content in the blend membranes was increased. Scanning electron microscopic investigations indicated the formation of pores in the membranes after a leaching cycle. The potential of the membrane for the use in the release application was tested with model organic dyes rhodamine B, methyl orange and fluorescein. Results from the release study indicate that the membranes can be used for the release of cationic dyes.
19 citations
TL;DR: In this article, the effects of the PMMA content and the crosslinker level in poly(methylmethacrylate) component on the dynamic and physico-mechanical properties of semi-2 interpenetrating polymer networks based on natural rubber and poly (methylmethylamine) were determined.
Abstract: The effects of the PMMA content and the cross-linker level in the poly(methylmethacrylate) component on the dynamic and physico-mechanical properties of semi-2 interpenetrating polymer networks based on natural rubber and poly(methylmethacrylate) were determined. The miscibility of the components in these semi-2 interpenetrating polymer networks was determined using the loss tangent data, obtained from dynamic mechanical thermal analysis and the interphase contents were calculated from modulated scanning calorimetric data. Some component mixing in these semi-2 interpenetrating polymer networks was evident from these modulated differential scanning calorimetric and dynamic mechanical thermal analysis data. The degree of component mixing increased with cross-linker level in the PMMA phase. The PMMA content in the semi-2 IPNs has a significant effect on the tensile and hysteresis behavior of these semi-2 interpenetrating polymer networks. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
11 citations
References
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Book•
31 May 1981TL;DR: In this paper, the authors point out the wealth of work done on inter penetrating polymer networks (IPNs) or closely related materials and point out that many papers and patents are not so designated, this literature is significantly larger than first imagined.
Abstract: To the surprise of practically no one, research and engineering on multi polymer materials has steadily increased through the 1960s and 1970s More and more people are remarking that we are running out of new monomers to polymerize, and that the improved polymers of the future will depend heavily on synergistic combinations of existing materials In the era of the mid-1960s, three distinct multipolymer combinations were recognized: polymer blends, grafts, and blocks Although inter penetrating polymer networks, lPNs, were prepared very early in polymer history, and already named by Millar in 1960, they played a relatively low-key role in polymer research developments until the late 1960s and 1970s I would prefer to consider the IPNs as a subdivision of the graft copolymers Yet the unique topology of the IPNs imparts properties not easily obtainable without the presence of crosslinking One of the objectives of this book is to point out the wealth of work done on IPNs or closely related materials Since many papers and patents actually concerned with IPNs are not so designated, this literature is significantly larger than first imagined It may also be that many authors will meet each other for the first time on these pages and realize that they are working on a common topology The number of applications suggested in the patent literature is large and growing Included are impact-resistant plastics, ion exchange resins, noise-damping materials, a type of thermoplastic elastomer, and many more"
811 citations
52 citations
TL;DR: In this article, the engineering properties of polyurethane-poly(methyl methacrylate) simultaneous interpenetrating networks (SINs) were evaluated and the results indicated that the reinforcement in the ultimate tensile strength was not directly related to increased physical entanglement crosslinks but indirectly related by reducing the rigid phase domain sizes and increasing the adhesion between the two phases, thus enhancing the filler-reinforcing effect similar to that observed in a carbon black-filled rubber.
Abstract: The engineering properties of polyurethane–poly(methyl methacrylate) simultaneous interpenetrating networks (SIN's) were evaluated. The hardness behavior reflected the observed phase inversion in the electron-microscopic studies. The maximum ultimate tensile strength was observed at 85% polyurethane–15% poly(methyl methacrylate) IPN and was due to the filler-reinforcing effect of the rigid poly(methyl methacrylate) phase. The ultimate tensile strenght of the 75/25 polyurethane–poly(methyl methacrylate) IPN was higher than that of the corresponding pseudo-IPN's (only one network crosslinked) and the linear blend. The leathery and glassy compositions did not show any reinforcement in the ultimate tensile strength. This indicated that the reinforcement in the ultimate tensile strength was not directly related to interpenetration (by increased physical entanglement crosslinks), but indirectly related by reducing the rigid phase domain sizes and increasing the adhesion between the two phases, thus enhancing the filler-reinforcing effect similar to that observed in a carbon black-filled rubber. The tear strengths of the polyurethane-rich IPN's pseudo-IPN's, and linear blends were found to be higher than that of the pure polyurethane as a combined result of increased modulus and tensile strength. The weight retentions in the thermal decomposition of the IPN's, pseudo-IPN's, and linear blends were higher than the proportional average of the component networks. The results seemed to indicate that this enhancement was related to the presence of the unzipped methyl methacrylate monomer. It was suggested that the monomers acted as radical scavengers in the polyurethane degradation, thus delaying the further reaction of the polyurethane radicals into volatile amines, isocyanates, alcohols, olefins, and carbon dioxide.
48 citations
TL;DR: In this paper, microtomed blocks of acrylonitrileitrile-butadiene-styrene (ABS), high impact poly styrene (HIPS), and highimpact poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) were etched with a mixture of chromic and phosphoric acids, and examined in optical and scanning-electron microscopes.
42 citations
TL;DR: The morphology and loss properties of polymeric composites of poly(methyl methacrylate) (PMMA) and polyurethane (PU) prepared according to an interstitial method have been studied as discussed by the authors.
39 citations