Cure Characteristic and Mechanical Properties of Epoxidized Natural Rubber/Chloroprene (ENR/CR) Blends

2010 ◽  
Vol 93-94 ◽  
pp. 631-634
Author(s):  
Chanchai Thongpin ◽  
Piyaporn Niltui ◽  
Piyapong Sornwaneenawakhun ◽  
Tossaporn Maneeprom ◽  
Saovaros Malithong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Epoxidized Natural Rubber ◽  
Maximum Torque ◽  
Tear Strength ◽  
Rubber Compounds ◽  
Cure Time ◽  
Chloroprene Rubber ◽  
Cure Characteristic ◽  
Two Phases

Epoxidized Natural rubber (ENR) with the epoxide content of 40 % was prepared and blended with various contents of chloroprene rubber (CR) and 50 phr of carbon black. The cure characteristic, mechanical properties and the effect of gasohol E-85 on the mechanical properties of the rubber vulcanizate were studied. It was revealed from cure characteristic results, tested by Moving Die Rheometer (MDR), that minimum torque of the rubber compounds increased with the content of CR whereas maximum torque tended to increase at the content of 10 phr and decrease after this content, of which the values agreed well with the modulus at 100% elongation in rubber vulcanizates. Considering characteristic scorch and cure time, the values increased with the CR contents. It was clear from the result that at the ENR:CR ratio of 90:10, modulus of 100% elongation and tear strength exhibited the highest values. It was also found that the mechanical properties of the blend vulcanizates were slightly suffered by gasohol E85 except for tear strength. It was understood that this must be because of the effect of the phase continuity and crosslinking that occurred differently in two phases. The phase morphology of the blends were also investigated and reported in the research.

The Effect of Second Filler on Cure Characteristic and Mechanical Properties of Si-69 Treated Precipitate Silica/NR Composite

2009 ◽  
Vol 79-82 ◽  
pp. 2183-2186 ◽  
Author(s):  
Chanchai Thongpin ◽  
C. Sripetdee ◽  
N. Papaka ◽  
N. Pongsathornviwa ◽  
Narongrit Sombatsompop
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Fly Ash ◽  
Rubber Compound ◽  
Maximum Torque ◽  
Elongation At Break ◽  
Rubber Vulcanizate ◽  
Rubber Compounds ◽  
Cure Time ◽  
Cure Characteristic

Silica has been widely used as non-black reinforcing filler, however, the filler-filler interaction has been an important issue. Cure characteristic and mechanical properties of the rubber compound and rubber vulcanizate were affected both by filler-rubber interaction and filler-filler interaction. There have been, presently, a number of natural fillers which are also used as fillers for the rubber, i.e. fly ash, sawdust and zeolite. This work therefore will study the effect of second filler added into the 13% Si-69 treated precipitate silica (PSi) filled natural rubber compounds. It was revealed that the scorch and cure time of the rubber compound increased with the content of treated PSi. This was the effect of excess of the silane treated onto PSi which would agglomerate and form the cluster of polysiloxane and would then be able to absorb vulcanizing accelerator resulting in extending the scorch and cure time of the rubber compounds. However, this effect was over ruled with the reinforcing effect as could be seen by the increasing, with the contents of PSi, of maximum torque and mechanical properties of the vulcanizates. The NR compounded with treated PSi content of 20 phr selected to study the effect of excess silane on the cure characteristic of hybrid fillers NR composite. The addition of sawdust led to longer scorch time and cure time but not much change of the maximum torque. As expected, the modulus of the rubber vulcanizate increased with the sawdust content whereas the tensile strength and elongation at break decreased with the sawdust content. The incorporation of zeolite could accelerate the cure reaction therefore both scorch time and cure time decreased. The maximum torque also increased with the content of zeolite. Both modulus and tensile strength increased with the content of the zeolite whereas elongation at break tended to be unchanged. In the case of using fly ash as the second filler, the cure time tended to be unchanged. However, the maximum torque tended to be increased with the content of fly ash. It was found that the modulus, tensile strength increased but elongation at break decreased. Interestingly, the excess of Si-69 used effect pronouncedly for the addition of zeolite and fly ash cases as the excess silane could promote the interaction between fillers surface and rubber molecule accept for sawdust

Calophyllum Inophyllum Oil as Plasticizer in Natural Rubber Compounds

2009 ◽  
Vol 25 (2) ◽  
pp. 113-128 ◽  
Author(s):  
P. Raju ◽  
V. Nandanan ◽  
Sunil K.N. Kutty
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Thermal Studies ◽  
Calophyllum Inophyllum ◽  
Compression Set ◽  
Peak Rate ◽  
Rubber Compounds ◽  
Cure Time ◽  
Calophyllum Inophyllum Oil ◽  
Control Compound

Mechanical properties and the thermal degradation characteristics of natural rubber compounds with calophyllum inophyllum oil were compared to that of the control compound containing naphthenic oil. The compounds containing calophyllum inophyllum oil showed improved tensile strength, tear strength, modulus, compression set, abrasion resistance and resilience. Cure time was higher than the naphthenic oil mixes. Thermal studies showed an increase of 8 °C in the temperature of initiation of degradation and an increase of 6 °C in temperature at which the peak rate of degradation occurred. The peak rate of degradation was comparable to the control mix containing naphthenic oil.

Mechanochemical Devulcanization of Vulcanized Gum Natural Rubber

2005 ◽  
Vol 21 (3) ◽  
pp. 183-199
Author(s):  
G.K. Jana ◽  
C.K. Das
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Three Dimensional ◽  
Elongation At Break ◽  
Tear Strength ◽  
Vulcanized Rubber ◽  
Dimensional Network ◽  
Polymeric Chains ◽  
Cure Time

De-vulcanization of vulcanized elastomers represents a great challenge because of their three-dimensional network structure. Sulfur-cured gum natural rubbers containing three different sulfur/accelerator ratios were de-vulcanized by thio-acids. The process was carried out at 90 °C for 10 minutes in an open two-roll cracker-cum-mixing mill. Two concentrations of de-vulcanizing agent were tried in order to study the cleavage of the sulfidic bonds. The mechanical properties of the re-vulcanized rubber (like tensile strength, modulus, tear strength and elongation at break) were improved with increasing concentrations of de-vulcanizing agent, because the crosslink density increased. A decrease in scorch time and in optimum cure time and an increase in the state of cure were observed when vulcanized rubber was treated with high amounts of de-vulcanizing agent. The temperature of onset of degradation was also increased with increasing concentration of thio-acid. DMA analysis revealed that the storage modulus increased on re-vulcanization. From IR spectroscopy it was observed that oxidation of the main polymeric chains did not occur at the time of high temperature milling. Over 80% retention of the original mechanical properties (like tensile strength, modulus, tear strength and elongation at break) of the vulcanized natural rubber was achieved by this mechanochemical process.

The Effect of Excess Silane-69 Used for Surface Modification on Cure Characteristic and Mechanical Properties of Precipitated Silica Filled Natural Rubber (PSi/NR)

2009 ◽  
Vol 79-82 ◽  
pp. 2171-2174 ◽  
Author(s):  
Chanchai Thongpin ◽  
C. Sangnil ◽  
P. Suerkong ◽  
A. Pongpilaiprertti ◽  
Narongrit Sombatsompop
Keyword(s):  
Mechanical Properties ◽  
Surface Modification ◽  
Crosslinking Density ◽  
High Concentration ◽  
Precipitated Silica ◽  
Vulcanized Rubber ◽  
Rubber Compounds ◽  
Cure Time ◽  
Cure Characteristic ◽  
Characterization Test

This research is concentrated on the effect of concentration of silane-69 used for surface modification on precipitated silica (PSi), on cure characteristic and mechanical properties of PSi filled NR. The PSi content in this study was fixed at 20 phr in order to reveal the effect of silane used to modify PSi, on NR compound and vulcanizate. Moving Die Rheometer (MDR) was used to characterize cure characteristic of rubber compounds. Generally, scorch and cure time of NR would increase with the addition of PSi due to the absorption of accelerator on its surface whereas the addition of Si-69 modified PSi would reduce both scorch and cure time. It was found in this research that the excess amount of Si-69 used increased scorch and cure time of rubber compounds. This was thought to be that the excess of Si-69 led to the formation of polysiloxane clusters which could absorb accelerator in rubber compound and resulted in a prolonged scorch and cure time. In term of vulcanized rubber, it was found that maximum torque increased with the concentration of Si-69 up to 6 %. The polysiloxane formed during the cure characterization test was responsible for the slightly decreased torque after 6% of Si-69 treatment. Nonetheless, even with high concentration of Si-69 used, torque was still higher than that of untreated PSi filled NR. This is widely understood that sulfur atoms in Si-69 molecule are able to participate in the bonding between rubber and silane molecules resulted in the enhancement of crosslink density of the vulcanizate rubber. The increased of modulus at 200 % elongation, tensile strength under tension, with the silane concentration, was evidence of the crosslink enhancement. Tear strength and hardness of the vulcanizates exhibiting the increment, with the silane used, also clearly confirmed the bonding between Si-69 and rubber molecules. It was elucidated from the research that excess of Si-69 would lead to polysiloxane formation, cluster form of silane and crosslinking density. Scanning Electron Microscope (SEM) micrographs and swelling test are also presented to confirm the phenomena.

Mechanical Properties of Natural Rubber and Chloroprene Rubber Latex Blends

2011 ◽  
Vol 239-242 ◽  
pp. 1601-1604 ◽  
Author(s):  
Xiao Xue Liao ◽  
Hai Sheng Tan ◽  
Ming Chao Luo ◽  
Bing Tang ◽  
Shuang Quan Liao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Physical And Mechanical Properties ◽  
Epoxidized Natural Rubber ◽  
Latex Film ◽  
Rubber Latex ◽  
Oil Resistance ◽  
Chloroprene Rubber

The effects of the ratios of natural rubber latex (NRL)and chloroprene rubber latex(CRL) and the type of compatibilizer on physical and mechanical properties of latex film were researched.The oil resistance of vulcanized latex film was tested. The compatibility of the latex blends was also analyzed by TG/DTG method.The results showed that properties of latex film were best when ratio of NRL/CRL was 75/25. As the CRL content increased, oil resistance of latex film was improved. Epoxidized natural rubber latex improved compatibility of NRL and CRL blends.

Preparation and Properties of Sponge Rubber Based on Natural Rubber and Cassava Starch

2014 ◽  
Vol 931-932 ◽  
pp. 68-72
Author(s):  
Komsun Temna ◽  
Nitinart Saetung ◽  
Anuwat Saetung
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Cassava Starch ◽  
Interfacial Interaction ◽  
Morphological Properties ◽  
Elongation At Break ◽  
Cure Time ◽  
The Difference ◽  
Cure Characteristic

In this work, the sponge rubbers based on cassava starch masterbatch in latex phase with the difference technique (non-gelatinized and gelatinized cassava starch) were preformed. The cassava starch contents from 0 to 70 phr were also studied. The cure characteristic, mechanical and morphological properties were investigated. It was found that the scorch time and cure time were increased with an increasing of cassava starch contents in both techniques. The mechanical properties i.e., tensile strength, elongation at break and tear strength were decreased with an increasing of cassava starch contents, except 500% modulus. However, the sponge based on gelatinized technique gave the better mechanical properties than that of non-gelatinized cassava starch. The SEM micrographs of sponge NR from gelatinized technique were also able to confirm a good interfacial interaction between hydrophilic cassava starch and hydrophobic NR.

Influence of Filler Types on Mechanical Properties and Cure Characteristics of Natural Rubber Composites

2011 ◽  
Vol 264-265 ◽  
pp. 646-651 ◽  
Author(s):  
Wittawat Wongsorat ◽  
Nitinat Suppakarn ◽  
Kasama Jarukumjorn
Keyword(s):  
Mechanical Properties ◽  
Calcium Carbonate ◽  
Carbon Black ◽  
Natural Rubber ◽  
Sisal Fiber ◽  
Maximum Torque ◽  
Cure Characteristics ◽  
Roll Mill ◽  
Fiber Treatment ◽  
Cure Time

Natural rubber (NR) was reinforced with three types of filler: carbon black, calcium carbonate, and sisal fiber. NR composites were prepared on a two-roll mill. Filler content was 20 phr. Mechanical properties and cure characteristics of NR composites were studied. All NR composites had higher maximum torque than NR. NR filled with carbon black showed the highest maximum torque. However, scorch time and cure time of the NR composites were not much affected by filler types. In addition, influence of fiber treatment (alkalization) on mechanical properties and cure characteristics of sisal fiber-NR composites was investigated. Alkali treated sisal fiber-NR composite exhibited higher tensile properties and hardness than untreated sisal fiber- NR composite due to improved adhesion between the fiber and NR matrix. Moreover, alkali treated sisal fiber-NR composite had superior specific modulus and strength than NR composites filled with carbon black and calcium carbonate.

The Effect of Chitosan Loading on the Properties of Chitosan Filled Epoxidized Natural Rubber Compounds

2011 ◽  
Vol 471-472 ◽  
pp. 851-856 ◽  
Author(s):  
S.M. Shaari ◽  
Hanafi Ismail ◽  
Nadras Othman
Keyword(s):  
Natural Rubber ◽  
Tensile Modulus ◽  
Epoxidized Natural Rubber ◽  
Rubber Matrix ◽  
Curing Time ◽  
Maximum Torque ◽  
Elongation At Break ◽  
Rubber Compounds ◽  
Curing Characteristics ◽  
Roll Mill

The study of chitosan loading onto epoxidized natural rubber compounds were prepared by incorporation of chitosan into epoxidised natural rubber matrix using a two-roll mill. The effects of chitosan loading on the curing characteristics, tensile properties and morphology of the compounds were investigated. Results indicated that slight changes in curing time (t90), and scorch time (tS2) of the compounds with the incorporation of chitosan. An increment is observed in the maximum torque, tensile modulus and durometer hardness of the compounds while tensile strength and elongation at break declines with chitosan loading.

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