The effects of the cross‐linking mechanism of low doses of gamma irradiation on the mechanical, thermal, and viscoelastic properties of the natural rubber latex/poly(styrene‐ block ‐isoprene‐ block ‐styrene) block copolymer blend

2021 ◽  
Author(s):  
Nurul Hakimah Lazim ◽  
Norsyahidah Mohd Hidzir ◽  
Naim Syauqi Hamzah ◽  
Takenaka Mikihito ◽  
Siti Aisyah Shamsudin
Keyword(s):  
Block Copolymer ◽  
Natural Rubber ◽  
Gamma Irradiation ◽  
Viscoelastic Properties ◽  
Natural Rubber Latex ◽  
Cross Linking ◽  
Low Doses ◽  
Rubber Latex ◽  
Copolymer Blend ◽  
The Cross

scholarly journals Grafting of n-butyl acrylate with natural rubber latex film by gamma radiation: a reaction mechanism

1970 ◽  
Vol 5 (1) ◽  
pp. 81-88 ◽  
Author(s):  
KMZ Hossain ◽  
AM Sarwaruddin Chowdhury
Keyword(s):  
Reaction Mechanism ◽  
Natural Rubber ◽  
Butyl Acrylate ◽  
Natural Rubber Latex ◽  
Latex Film ◽  
Cross Linking ◽  
Swelling Ratio ◽  
Cross Link ◽  
Rubber Latex ◽  
The Cross

Natural rubber latex (NRL) and n-butyl acrylate (n-BA) were blended and irradiated at various absorbed doses by gamma rays from Co-60 source at room temperature. The stabilizing effect was determined by measuring the pH and viscosity of NRL with n-BA with the storage time of five weeks. The cross-link density, swelling ratio of the radiation vulcanized rubber film were measured. The cross-link density of the n-BA grafted NRL film was found increasing and the swelling ratio of that film decreasing with the increased absorbed dose. The optimum radiation dose for better cross-linking of natural rubber latex blended with five parts per hundred rubber (phr) n-BA was found 15 kGy absorbed dose. Based on the cross-linking properties a probable cross-linking reaction mechanism for the n-BA grafted natural rubber latex film was developed. Keywords: Natural rubber latex, n-butyl acrylate, Irradiation, Swelling ratio, Cross-link, Reaction mechanism. DOI: 10.3329/diujst.v5i1.4386 Daffodil International University Journal of Science and Technology Vol.5(1) 2010 pp.81-88

METHOD TO VULCANIZE NATURAL RUBBER FROM MEDIUM AMMONIA LATEX BY USING GLUTARALDEHYDE

2012 ◽  
Vol 85 (4) ◽  
pp. 565-575 ◽  
Author(s):  
Jobish Johns ◽  
Charoen Nakason ◽  
Anoma Thitithammawong ◽  
Pairote Klinpituksa
Keyword(s):  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Ammonium Hydroxide ◽  
Mechanical Analysis ◽  
Cross Linking ◽  
Mechanical And Thermal Properties ◽  
Rubber Latex ◽  
Vulcanized Rubber ◽  
Link Density ◽  
The Cross

ABSTRACT A novel and inexpensive method for vulcanizing natural rubber by using glutaraldehyde was introduced. The vulcanized rubber samples were prepared by adding various amounts of glutaraldehyde to medium ammonia natural rubber latex. Cross-linking reaction occurred only in the presence of ammonium hydroxide in natural rubber latex upon the addition of glutaraldehyde. Cross-linked rubber has been obtained by reacting natural rubber with pentane-1,5-diylidenediamine formed from the reaction between glutaraldehyde and ammonia. The vulcanized materials were characterized by mechanical analysis and thermogravimetry. The results revealed an improvement in mechanical and thermal properties by vulcanization. Activation energy of degradation has been calculated using the Horowitz-Metzger equation. The cross-link density of the vulcanized rubber was determined from swelling experiments in benzene. Fourier transform infrared spectroscopy has been employed to confirm the cross-linking reaction between rubber molecules. From the overall characterizations, natural rubber vulcanized with 12 mL of 10% glutaraldehyde exhibited better properties.

scholarly journals Physicochemical, Thermomechanical, and Swelling Properties of Radiation Vulcanised Natural Rubber Latex Film: Effect of Diospyros peregrina Fruit Extracts

2013 ◽  
Vol 2013 ◽  
pp. 1-8
Author(s):  
Kazi Md Zakir Hossain ◽  
Nashid Sharif ◽  
N. C. Dafader ◽  
M. E. Haque ◽  
A. M. Sarwaruddin Chowdhury
Keyword(s):  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Tensile Modulus ◽  
Decomposition Temperature ◽  
Latex Film ◽  
Cross Linking ◽  
Rubber Latex ◽  
Swelling Properties ◽  
Fruit Extracts ◽  
Control Film

A range of radiation vulcanised natural rubber latex (RVNRL) films were prepared using various concentrations of aqueous extracts of mature Diospyros peregrina fruit, which acted as a cross-linking agent. The surface of the RVNRL films exhibited an aggregated morphology of the rubber hydrocarbon with increasing roughness due to increasing fruit extract contents in the latex. An improvement in tensile strength, tensile modulus, and storage modulus of RVNRL films was observed with the addition of fruit extracts compared to the control film due to their cross-linking effect. The glass transition (Tg) temperature of all the RVNRL films was found to be at around −61.5°C. The films were also observed to be thermally stable up to 325°C, while the maximum decomposition temperature appeared at around 375°C. The incorporation of fruit extracts further revealed a significant influence on increasing the crystallinity, gel content, and physical cross-link density of the RVNRL films.

scholarly journals Roles of Chitosan as Bio-Fillers in Radiation-Vulcanized Natural Rubber Latex and Hybrid Radiation and Peroxide-Vulcanized Natural Rubber Latex: Physical/Mechanical Properties under Thermal Aging and Biodegradability

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3940
Author(s):  
Arkarapol Thumwong ◽  
Worawat Poltabtim ◽  
Patcharaporn Kerdsang ◽  
Kiadtisak Saenboonruang
Keyword(s):  
Weight Loss ◽  
Natural Rubber ◽  
Gamma Irradiation ◽  
Thermal Aging ◽  
Color Change ◽  
Color Space ◽  
Natural Rubber Latex ◽  
Tensile Modulus ◽  
Rubber Latex ◽  
Environmental Friendliness

Although natural rubber was regarded as biodegradable, the degradation is a time-consuming process that could take weeks or months for any degradation or substantial weight loss to be observable, resulting in the need for novel processes/methods to accelerate the rubber degradation. As a result, this work investigated the potential utilization of chitosan (CS) as a biodegradation enhancer for radiation-vulcanized natural rubber latex (R-VNRL) and hybrid radiation and peroxide-vulcanized natural rubber latex (RP-VNRL) composites, with varying CS contents (0, 2, 4, or 6 phr). The R-VNRL samples were prepared using 15 kGy gamma irradiation, while the RP-VNRL samples were prepared using a combination of 0.1 phr tert-butyl hydroperoxide (t-BHPO) and 10 kGy gamma irradiation. The properties investigated were biodegradability in the soil and the morphological, chemical, mechanical, and physical properties, both before and after undergoing thermal aging. The results indicated that the biodegradability of both the R-VNRL and RP-VNRL composites was enhanced with the addition of CS, as evidenced by increases in the percentage weight loss (% weight loss) after being buried in soil for 8 weeks from 6.5 ± 0.1% and 6.4 ± 0.1% in a pristine R-VNRL and RP-VNRL samples, respectively, to 10.5 ± 0.1% and 10.2 ± 0.1% in 6-pph CS/R-VNRL and 6-pph CS/RP-VNRL composites, respectively, indicating the biodegradation enhancement of approximately 60%. In addition, the results revealed that the addition of CS could increase the value of tensile modulus by 119%, while decrease the values of tensile strength and elongation at break by 50% and 43%, respectively, in the specimens containing 6-phr CS. In terms of the color appearances, the samples were lighter and yellower after the addition of CS, as evidenced by the noticeably increased L* and b* values, based on the CIE L*a*b* color space system. Furthermore, the investigation into the effects of thermal aging showed that the overall tensile properties for both curing systems were reduced, while varying degrees of color change were observed, with the pristine R-VNRL and RP-VNRL samples having more pronounced degradation/changes for both properties. In conclusion, the overall results suggested that CS had great potential to be applied as a bio-filler in R-VNRL and RP-VNRL composites to effectively promote the biodegradability, environmental friendliness, and resistance to thermal degradation of the composites.

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