Addition Of Liquid Natural Rubber Research Articles

The Compatibilty of TPU and NR Blends

The blends of thermoplastic polyurethane (TPU) with natural rubber (NR) at four different blends ratios were prepared via melt blending, with addition of liquid natural rubber (LNR) as compatibilizer. The effect of blend ratio and temperature on the tensile properties and swelling ratio was studied. The addition of NR and LNR into TPU produces a decrease of tensile strength. The swelling ratio increased with the increasing of NR content in the blends. The temperatures of blending also give effects to tensile properties and swelling behavior.

Effects of NR and Liquid NR Loading on Swelling Behaviour of TPU/NR Blends

The blends of thermoplastic polyurethane (TPU) with natural rubber (NR) at four different blend ratios were prepared via melt blending at 180°C and 190°C, with addition of liquid natural rubber (LNR) as compatibilizer. The effect of blend ratio and temperature swelling index was studied. The equilibrium swelling index of TPU and its blend increase with increasing of NR, because of the easiness for solvent to diffuse into the gap between rubber molecules. The temperatures of blending also give effect to swelling behavior. Swelling index of all samples was higher when mixed the blends at higher temperature.

Effect Of Liquid Natural Rubber Addition To The Mechanical Properties Of Elastomeric Thermoplastic / Polyethylene Polyblend

Addition of liquid natural rubber (LNR) to elastomeric thermoplastic (ETP)/polyethylene (PE) polyblend has been done. The aim of this research is to study the effect of LNR addition to the ETP /PE polyblend using blending process. The blending process was done by mixing of ETP and PE with composition of 30% and 70% by weight respectively. LNR was added to the ETP /PE with composition of 3%, 5%, and 7% by weight, to form composite materials, refer as PLB-3, PLB-5 and PLB-7. The density of the specimen was measure by picno-meter, the mechanical properties were tested by Stograph R-1, the thermal property was analyzed by Differential Thermal Analysis (DTA) and the microstructure was observed by Scanning Electron Microscope (SEM). The result shows that the melting point of ETP/PE poly-blend increased from near 140 o C to near 160 o C with addition of LNR, but decomposition temperature decreased. Likewise, the mechanical properties of ETP/PE poly-blend exhibit the improvement after being added LNR. The mechanical properties show a rigid structure with the highest tensile strength of 191 Kg.m -2 , and referred as the most optimum composition ETP/PE poly-blend. This condition is reached with addition of 5% by weight LNR showing regular and homogenous microstructure. It can be concluded that the addition of LNR could improve miscibility of ETP/PE, so that a better quality was obtained.

Mechanical Properties and Environmental Stress Cracking Resistance of Rubber Toughened Polyester/Clay Composite

Crosslinked polyester clay nanocomposites were prepared by dispersing originically modified montmorillonite in prepromoted polyester resin and subsequently crosslinked using methyl ethyl ketone peroxide catalyst at different clay concentration. Cure process and the mechanical properties of rubber toughened polyester clay composite have been studied. Rubber toughened thermoset polyester composite were prepared by adding 3 per hundred rubber (phr) of liquid natural rubber (LNR) was used in the mixing of producing this composite. Modification of polyester matrix was done due to the brittle problem of polyester composite. Addition of LNR will increase the toughness of composite and produce ductile polyester. Two types of composites were produced which is clay-lnr polyester composite and clay polyester composite. Addition of liquid natural rubber significantly increased the impact strength and flexural properties. Result shows that addition of 6% of clay-lnr composite give good properties on impact, strength and flexural. From the ESCR test, both composites showed good resistance to environmental.

Effects of PBO fiber and clay on the mechanical, morphological, and dynamic mechanical properties of NR/HDPE blends

AbstractPoly(p‐phenylene‐2,6‐benzobisoksazole) (PBO) and natural rubber (NR)/high density polyethylene (HDPE) composites were melt‐blended in a Haake internal mixer. The tensile strength, tensile modulus, and impact strength increased with fiber loading and optimized at 20%. Incorporation of clay into the NR/HDPE/PBO composites resulted in an improvement of tensile strength for NR/HDPE/PBO composites compared to the systems without clay. However, addition of clay was only effective at low contents (5–7.5%). Additional improvement of tensile strength, tensile modulus, and impact strength of the hybrid composite was observed on addition of liquid natural rubber (LNR). Scanning electron micrographs of the samples had indicated that the presence of clay decreased the domain size of the dispersed phase. Results on dynamic response showed that incorporation of clay and LNR into the composites had increased the storage modulus and reduced the tan δ. The shift of glass transition temperature (Tg) to higher values for composites also indicated good interaction between the fiber and the matrix. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers.

Changes in morphology and properties of NR–NBR blends. Effect of viscosity ratio modified by liquid natural rubber and epoxidised liquid natural rubber

Changes in rheological properties, morphology, and oil resistance in NR–NBR blends by viscosity ratio have been investigated. In this study, the viscosity ratio was modified by mechanical mastication and addition of liquid natural rubber (LNR) and epoxidised liquid natural rubber (ELNR). The results reveal that as viscosity ratio increased from 0·5 to 1·0, Mooney viscosity of the blends increased, and then decreased sharply as the viscosity ratio further increased from 1·0 to 2·0. The addition of LNR and ELNR for plasticising NR and NBR, respectively, does not significantly affect cure properties of the blends. The phase size of the NR dispersed phase depends strongly on the viscosity ratio. The high viscosity of the matrix and/or the low viscosity of the dispersed phase promote breaking up of the dispersed phase. Unexpectedly, a decrease in size of the dispersed phase by the modification of viscosity ratio via the use of low molecular weight rubber (i.e. LNR and ELNR) did not result in an improvement in oil resistance.

Physical and rheological characteristics of liquid natural rubber modified bitumen

Polymer modification of commercially available bitumen has been attempted by the incorporation of liquid natural rubber (LNR) of medium viscosity. Both soft and blown bitumens have been studied. Physical and rheological characteristics of the samples were investigated. Improvement in physical properties such as shear strength and ductility in the case of blown bitumen and resistance to flow in the case of soft bitumen were observed. It was also found that as a result of addition of LNR, the activation energy of flow increases in the case of soft bitumen and decreases in blown bitumen. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68:53–61, 1998

Blending of natural rubber with linear low‐density polyethylene

AbstractBlends of natural rubber (NR) with linear low‐density polyethylene (LLDPE) were prepared by melt blending of the materials in a plasticorder mixer at various temperatures around the melting point of LLDPE and at various mixing rates. The optimum processing conditions were a temperature of about 135°C and a mixing rate of 55 rpm. The tensile properties, stress and strain, of the blend had improved significantly with the addition of liquid natural rubber (LNR) into the blend. For blends with compositions around 50% NR, about 10–15% LNR produced the most significant improvement in the physical properties. Welldispersed plastic particles in a rubber matrix were strongly indicated in these samples. Scanning electron micrographs (SEM) of the samples also indicated an increase in the homogeneity of the mixes with the addition of LNR. A single glass transition temperature of about−55°C for the blend was observed via dynamic mechanical analysis (DMA). Interfacial linking between the NR and LLDPE phases was attributed to the presence of active groups on the polyisoprene chain of LNR, which induced the interphase reaction between the NR and LLDPE phases. © 1995 John Wiley & Sons, Inc.

Natural rubber–HDPE blends with liquid natural rubber as a compatibilizer. I. Thermal and mechanical properties

AbstractThe measurement of physical properties of thermoplastic natural rubber (TPNR) of NR–HDPE blends have been made at various compositions of high‐density polyethylene (HDPE). The tensile properties and hardness of TPNR improve significantly with the addition of liquid natural rubber (LNR) to the blend. The degree of cross‐linking also increases with increasing amount of LNR added. The LNR with molecular weight (Mw) of 50,000 and reactive terminals promotes cross‐linking within the rubber phase and grafting of the polyethylene chains onto the rubber matrix system. The maximum stress and strain of the blends measured are about 7.5 MPa and 1000%, respectively. Dynamic mechanical analysis results indicate a single Tg on a tan δ trace at about −50 and −55°C for the two types of blends, respectively. © 1994 John Wiley & Sons, Inc.