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Curing characteristics of chlorosulphonated polyethylene and natural rubber blends
Journal of the Serbian Chemical Society , 2005,
Abstract: The dependence of the Mooney scorch time and cure index on the blend ratio of chlorosulphonated polyethylene/natural rubber (CSM/SMR 20 CV) and chlorosulphonated polyethylene/chlorinated natural rubber (CSM/Pergut S 40) blends were determined in the temperature range from 120 oC to 160 oC using a Monsanto Mooney viscometer. Semi-efficient vulcanization systems were used for the study. The morphology of the fracture surface of the crosslinked systems was determined by Scanning Electron Microscopy (SEM). The results showed that the scorch time decreased with increasing SMR 20 CV and Pergut S 40 contents. This observation is attributed to the increasing solubility of sulfur, as the content of SMR 20 CV and Pergut S 40 in the composition increased. For temperatures greater than 140 oC, the dependence of the scorch time on blend ratios diminishes, as enough thermal energy is available to overcome the activation energy of vulcanization. The differing curing characteristics of the two blends is explained by the compatibility factor of the respective blend. Morphological analysis of the blends shows a very satisfactory agreement.
Compatibilization of natural rubber (NR) and chlorosulfonated polyethylene (CSM) blends with zinc salts of sulfonated natural rubber
Kwanruethai Boonsong,Manus Seadan,Natinee Lopattananon
Songklanakarin Journal of Science and Technology , 2008,
Abstract: A rubbery ionomer of zinc salt of sulfonated natural rubbers (Zn-SNR) was synthesized and used as a new compatibilizerfor the blends of natural rubber (NR) and chlorosulfonated polyethylene (CSM). Epoxidized natural rubber (ENR)was also used for the preparation of NR/CSM blends. The effect of ionomer concentration on melt viscosity of the 50/50(%wt/wt) NR/CSM blends at different constant shear rates was characterized. It was found that the incorporation of ionomerincreased shear viscosity of the blends, indicating an increase in interfacial interaction between the NR and CSM. Themaximum shear viscosity was observed when the ionomer of 10% by weight of NR was added into the blends. The tensile,tear, oil resistant properties and morphology of the various 20/80 NR/CSM blends with and without the Zn-SNR and ENR atthe 10% wt of NR were examined. The 100% modulus, tensile strength, tear strength and oil resistance of the compatibilizedblends improved over those of the uncompatibilized blends. The blends compatibilized with the Zn-SNR showed higher levelsof improvement in modulus, tensile and tear strength than those of ENR. The tensile strength of 20/80 blends with the Zn-SNRand ENR compatibilizers increased by 38 and 30% over the corresponding neat blends. Furthermore, the addition of ionomerand ENR resulted in decreased domain of dispersed NR phase size and improved interfacial adhesion between the NR andCSM, indicating enhanced blend compatibility. These results suggest that the Zn-SNR is a new effective compatibilizer forNR and CSM blends.
Influence of Poly(vinyl chloride) on Natural Rubber/Chlorosulfonated Polyethylene Blends  [PDF]
Manisara Phiriyawirut, Sawanya Luamlam
Open Journal of Organic Polymer Materials (OJOPM) , 2013, DOI: 10.4236/ojopm.2013.34013

Blend of natural rubber (NR) and chlorosulfonated polyethylene (CSM) was so interesting due to binding of the good oil resistance of CSM, the good mechanical properties and low cost of NR. However, due to the different polarities of two rubbers, phase separation and inferior properties of NR/CSM blend were obtained. The practical way to improve its properties is the addition of the third component to bind both phases of the blend. Effects of poly(vinyl chloride), PVC as compatibilizer on cure characteristics, morphology, mechanical properties and automotive fuel resistance of NR/ CSM blend were investigated. In this contribution, NR/CSM blend with blend ratio of 50/50 was prepared using a two-roll mill, and then vulcanized in a compression mold at 160°C. The PVC content was varied from 1 to 7 phr. It was found that the usage of 7 phr PVC led to improve interaction between NR and CSM phases. Therefore, increase in cure characteristics, mechanical strength and automotive fuel resistance of the blend was observed.


QIN Chuan,YIN Jing-hua,HUANG Bao-tong,

高分子学报 , 1989,
Abstract: Compatibility of natural rubber (NR)/low density polyethylene blends was calculated and it was predicted that compatibility existed between the amorphous part of polyethylene and NR. Based on above calculation and prediction, an interaction model of polyethylene and NR was suggested. Effective network chain density measurement, dynamic mechanical spectrum measurement, wide angle X-ray diffraction and density measurement have been used to verify the compatibility of natural rubber/low density polyethylene blends (NR either unvulcanized or vulcanized) as predicted by the calculation and proposed model. Experimental results show that there exist certain interaction between amorphous LDPE and NR.

LU Yan,QIN Chuan,JING Xia-bin,HUANG Bao-tong,

高分子学报 , 1991,
Abstract: Two polyethylene/rubber blends, LLDPE/NR and LLDPE/SBR, were examined by FTIR-ATR spectroscopy and dynamic Tg measurements. It was found that the 835 cm-1 band of the NR and the 964cm-1 band of the SBR became higher and narrower as a result of blending with LLDPE, indicating certain extent of interaction between the amorphous molecular segments of PE and the rubber molecles. The Tg changes determined by dynamic techniques supported the result obtained by IR spectroscopy.
High Performance Oil Resistant Rubber  [PDF]
A. I. Khalaf, A. A. Yehia, M. N. Ismail, H. El-Sabbagh
Open Journal of Organic Polymer Materials (OJOPM) , 2012, DOI: 10.4236/ojopm.2012.24013
Abstract: Blending of polymers has gained much interest due to the fact that, it can be used to produce new polymeric materials with specific properties suitable for some special applications. The blends from acrylonitrile butadiene rubber (NBR), chloroprene rubber (CR) and polyvinyl chloride (PVC) has been designed for products working in contact with oils. The characteristics of the designed blends either binary blends (NBR/PVC or PVC/CR) or ternary blends (NBR/ PVC/CR) were investigated by rheological properties, mechanical analysis and swelling in oil and toluene. It was found that the incorporation of PVC in the blend compositions leads to the decrease in degree of swelling, the penetration rate and the average diffusion coefficient. On the other hand the ultimate tensile strength (UTS), the hardness and strain energy were increased. This was attributed to the plastic nature of PVC, beside its additional behavior as filler. The crosslinking density in the blend vulcanizates under investigations was determined by Flory-Rehner and Mooney-Rivlin [Stress/Strain] equations. The higher values of crosslinking density determined by Mooney-Rivlin can be attributed to the additional physical crosslinks (e.g. entanglements etc), beside the chemical crosslinks determined by swelling in toluene. This study showed that NBR/PVC blends are characterized with high performance oil resistant, which can be recommended to automotive industry.
Improved Automotive Fuel Resistance of Natural Rubber/Chlorosulfonated Polyethylene Blends by Blending Epoxidized Natural Polymer  [PDF]
Manisara Phiriyawirut, Sawanya Luamlam
Open Journal of Organic Polymer Materials (OJOPM) , 2013, DOI: 10.4236/ojopm.2013.34017

The natural rubber (NR) was mixed with chlorosulfonated polyethylene (CSM), due to the difference of polarity in NR and CSM made this blend incompatible and the third component was used. Epoxidzed natural rubber (ENR) was used as a third component. NR/CSM blended with the blend ratio of 50/50 was prepared by using a two-roll mill and vulcanization in a compression mold at 160°C. The ENR content was varied from 1 to 7 phr. The curing characteristics, morphology, mechanical properties, and automotive fuel swelling were investigated. The results indicated that the cure time of the blend rubbers was shorter as adding ENR. The mechanical properties of the blend rubbers were not affected by ENR content. However, automotive fuel resistance of the blend rubbers was found to increase with adding ENR in rubber blend.

Gordana Markovi?,Vojislav Jovanovi?,Suzana Samar?ija-Jovanovi?,Milena Marinovi?-Cincovi?
Chemical Industry and Chemical Engineering Quarterly , 2011,
Abstract: In this paper, the curing and mechanical properties of two series of prepared blends, i.e., chlorosulphonated polyethylene (CSM)/isobutylene-co-isoprene (IIR) rubber blends and chlorosulphonated polyethylene (CSM)/chlorinated isobutylene-co-isoprene (CIIR) rubber blends were carried out. Blends were prepared using a two-roll mill at a temperature of 40-50 °C. The curing was assessed using a Monsanto oscillating disc rheometer R-100. The process of vulcanization accelerated sulfur of pure rubbers and their blends was carried out in an electrically heated laboratory hydraulic press under a pressure of about 4 MPa and 160 °C. The stress-strain experiments were performed using a tensile tester machine (Zwick 1425). Results indicate that the scorch time, ts2, and optimum cure time, tc90, increase with increasing CSM content in both blends. The value of modulus at 100 and 300% elongation and tensile strength increases with increasing CSM content, whereas elongation at break shows a decreasing trend. The enhancement in mechanical properties was supported by data of crosslink density in these samples obtained from swelling measurement and scanning electron microscopy studies of the rubber blends fractured surfaces
Academic Research International , 2012,
Abstract: The sorption characteristics of dynamically vulcanized polypropylene/epoxidized natural rubber blends filled with carbonized Dika nutshell have been investigated with specialreference to the effects of filler carbonization temperature and dosage of cross-linking agent. Toluene, an aromatic solvent commonly used in the rubber industry, was chosen as the solvent in this investigation. The filled blends were prepared by compression moulding using maleic anhydride-graft-polypropylene as a compatibilizer. The blend morphology was studied using Scanning Electron Microscope (SEM). Both the SEM and dynamic vulcanization studies indicate that the non-compatibilized/ non-vulcanized blends are immiscible and form twophase structures, accompanied by high solvent (toluene) uptake. Resistance to toluene sorptionincreased with increase in the dosage of cross-linking agent due to increase in cross-link density as a result of increase in network formation. This behaviour is supported by SEM micrographs of vulcanized and non-vulcanized blends, which reveal restriction to swelling of vulcanized blends due to increase in network formation. Resistance to toluene sorption with increase in filler carbonization temperature was also observed. This is attributed to increasein surface area of the filler due to the elimination of volatile matter that are deleterious to the blend-filler interfacial interaction.

FANG Zheng-ping,XU Cheng-wei,

高分子学报 , 1995,
Abstract: According to mastication degradation mechanism and long-chain molecular model, the equation of TQ= TQ0(t+1)-n was introduced to reveal the rheological behavior of HDPE/NR blends.DSC results showed that partial NR chains rheowere clamped by HDPE crystals and thus act as the tie molecules in the blend.Small amount of NR can improve HDPE's tensile elongation and environmental stress cracking resistance dramatically,while the melt flow property maintained because of the degradation of NR.
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