scholarly journals Curing characteristics of chlorosulphonated polyethylene and natural rubber blends

2005 ◽  
Vol 70 (5) ◽  
pp. 695-703 ◽  
Author(s):  
Gordana Markovic ◽  
Blaga Radovanovic ◽  
Jaroslava Budinski-Simendic ◽  
Milena Marinovic-Cincovic
Keyword(s):  
Electron Microscopy ◽  
Natural Rubber ◽  
Morphological Analysis ◽  
Blend Ratio ◽  
Rubber Blends ◽  
Curing Characteristics ◽  
Compatibility Factor ◽  
Chlorosulphonated Polyethylene ◽  
Blend Ratios ◽  
Scanning Electron

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.

SYNERGISTIC REINFORCEMENT OF ORGANOCLAY AND DOUBLE NETWORKING IN NATURAL RUBBER

2013 ◽  
Vol 86 (2) ◽  
pp. 205-217 ◽  
Author(s):  
Hedayatollah Sadeghi Ghari ◽  
Zahra Shakouri
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Natural Rubber ◽  
Physical And Mechanical Properties ◽  
X Ray Diffraction ◽  
Double Network ◽  
X Ray ◽  
Extension Ratio ◽  
Curing Characteristics ◽  
Scanning Electron

ABSTRACT Research was undertaken on natural rubber (NR) nanocomposites with organoclays. A double-network (DN) structure is formed when a partially cross-linked elastomer is further cross-linked during a state of strain. Two methods were used in the preparation of NR/organoclay nanocomposites: the ordinary method (single-network NR nanocomposite) and double-networked NR (DN-NR) nanocomposites. The single-networked NR nanocomposites were used for comparison. The effects of organoclay (5 phr) with a different extension ratio on curing characteristics, mechanical properties, hardness, swelling behavior, and morphology of single- and double-networked NR nanocomposites were studied. The results showed that double-networked NR nanocomposites exhibited higher physical and mechanical properties. The tensile strength of DN-NR nanocomposites increased up to 33 MPa (more than four times greater than that of pure NR) and then decreased with an increasing extension ratio. Modulus and hardness continuously increased with an increased extension ratio. The microstructure of the NR/organoclay systems was studied by X-ray diffraction and field emission scanning electron microscopy. The effects of different extension ratios on the dispersion of organoclay layers in the nanocomposites were investigated. Generally, results showed that the optimized extension ratio in DN nanocomposites was equal (or about or around) to α= 2.

Mechanical and Morphological Properties of Sulfur-Cured Natural Rubber/Polyethylene/Epoxidized Natural Rubber Blends

2017 ◽  
Vol 757 ◽  
pp. 14-18
Author(s):  
Kritsada Phatcharasit ◽  
Wirach Taweepreda ◽  
Patompong Phummor
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Epoxidized Natural Rubber ◽  
Morphological Properties ◽  
Rubber Blends ◽  
Compression Set ◽  
Internal Mixer ◽  
Scanning Electron

The polymer blend was prepared from natural rubber (NR) and polyethylene (PE) powder blended with epoxidized natural rubber (ENR) by using an internal mixer. In this study, epoxidized natural rubber (ENR) was used as compatibilizer for the blends. Blending ENR with PE powder and NR were prepared at various compositions from 0-20% by weight. Then, specimens from the blends were produced by compression molding at 150 °C. The mechanical and morphological properties of the composites were investigated. It was found that the addition of ENR content has improved the tensile strength, compression set and hardness for the ternary compositions composed of NR/PE powder/ENR compared to the binary one (i.e. NR/PE powder). ENR contributed to a better dispersion between the NR and PE phases as observed in the scanning electron microscopy.

The effect of nanocrystalline cellulose and TEMPO-oxidized nanocellulose on the compatibility of polypropylene/cyclic natural rubber blends

2020 ◽  
pp. 089270572095912
Author(s):  
IP Mahendra ◽  
B Wirjosentono ◽  
T Tamrin ◽  
H Ismail ◽  
JA Mendez ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Natural Rubber ◽  
Nanocrystalline Cellulose ◽  
Mechanical And Thermal Properties ◽  
Interphase Surface ◽  
Sem Images ◽  
Morphological Effect ◽  
Rubber Blends ◽  
Compatibilizing Agent ◽  
Scanning Electron

The effect of nanocrystalline cellulose (NCC) and nanofiber cellulose (NFC) was estimated as a means of reinforcing and compatibilizing agent of polypropylene/ cyclic natural rubber (PP/CNR) blend in terms of mechanical and thermal properties. The morphological effect of NCC and NFC on the PP/CNR blend property was determined through several characterization techniques, i.e. SEM, contact and TGA/DTG. Scanning electron microscopy (SEM) images revealed that the addition of NCC and NFC became more homogenous than without the addition of nanocellulose. The improvement of nanocomposites was also observed on the result of interphase surface tension and thermal stability. This improvement was assumed as the result of physically/ chemically interaction of nanocellulose with the backbone of PP and CNR, in which the nanocellulose can be imagined acting as a bridge to link the PP and CNR’s backbone.

Cryoground Rubber-Natural Rubber Blends

1984 ◽  
Vol 57 (1) ◽  
pp. 19-33 ◽  
Author(s):  
A. A. Phadke ◽  
S. K. Chakraborty ◽  
S. K. De
Keyword(s):  
Electron Microscope ◽  
Carbon Black ◽  
Natural Rubber ◽  
Detrimental Effect ◽  
Rubber Blends ◽  
Curing Characteristics ◽  
Cure Time ◽  
Scanning Electron Microscope Fractographs ◽  
Higher Doses ◽  
Scanning Electron

Abstract Addition of cryoground rubber (CGR) causes changes in curing characteristics (decrease in Mooney scorch time, optimum cure time, and reversion time) and shows a detrimental effect on most of the vulcanizate properties (tensile, resilience, flex, hysteresis, set, and abrasion). Tear strength, however, is not adversely affected by CGR. Higher doses of curatives (sulfur 3.5 phr and acelerator 1.4 phr) and addition of reinforcing carbon black make up the losses in physical properties. Scanning electron microscope fractographs show that there is little adhesion between natural rubber and CGR. But addition of carbon black overshadows the effect of CGR, and the fractographs show the characteristics of black-filled vulcanizates.

scholarly journals Poly(L-lactic acid)/deproteinized natural rubber blends with enhanced compatibility

Polimery ◽  
2021 ◽  
Vol 66 (2) ◽  
pp. 105-111
Author(s):  
I Putu Mahendra ◽  
Phan Trung Nghia ◽  
Nguyen Thi Hong Phuong ◽  
Tring Thi Hang ◽  
Nur Fazreen Alias ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Lactic Acid ◽  
Natural Rubber ◽  
Pore Diameter ◽  
Low Molecular Weight ◽  
Co Catalyst ◽  
Rubber Blends ◽  
Deproteinized Natural Rubber ◽  
Scanning Electron

PLLA-g-LMWNR (LMWNR – low molecular weight natural rubber) was used as a compatibilizer (1–3 wt %) of poly(L-lactic acid)/deproteinized natural rubber (PLLA/DPNR) blend (95/5 w/w). The LMWNR was prepared using TiO2/ZnO (9 : 1 w/w) and H2O2 as co-catalyst. The obtained LMWNR was grafted with 0–12 wt % maleic anhydride (LMWNR-g-MA) and then with PLLA (PLLA-g-LMWNR). A significant improvement in the mechanical properties of the PLLA/DPNR blend was found in the blend that contained 3 wt % PLLA-g-LMWNR. Scanning electron microscopy showed a decrease in the pore diameter from 5.44 to 1.56 μm. The thermal analysis of PLLA/DPNR blends showed that the Tg value of PLLA phase shifted from 63.1 to 61.4°C. These results confirmed that PLLA-g-LMWNR can enhance the compatibility of the PLLA/DPNR blend.

scholarly journals Curing and mechanical properties of chlorosulphonated polyethylene rubber blends

2011 ◽  
Vol 17 (3) ◽  
pp. 315-321 ◽  
Author(s):  
Gordana Markovic ◽  
Vojislav Jovanovic ◽  
Suzana Samarzija-Jovanovic ◽  
Milena Marinovic-Cincovic ◽  
Jaroslava Budinski-Simendic
Keyword(s):  
Mechanical Properties ◽  
Crosslink Density ◽  
Hydraulic Press ◽  
Elongation At Break ◽  
Rubber Blends ◽  
Tensile Tester ◽  
Roll Mill ◽  
Cure Time ◽  
Chlorosulphonated Polyethylene ◽  
Scanning Electron

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 by 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?. The stress-strain experiments were performed using 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 values of modulus at 100% and at 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.

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