The Microstructure of Natural Rubber Latex Films

1997 ◽  
Vol 70 (4) ◽  
pp. 549-559 ◽  
Author(s):  
S. Cook ◽  
P. E. F. Cudby ◽  
R. T. Davies ◽  
M. D. Morris
Keyword(s):  
Electron Microscopy ◽  
Natural Rubber ◽  
Crosslink Density ◽  
Osmium Tetroxide ◽  
Natural Rubber Latex ◽  
Mesh Size ◽  
Latex Film ◽  
Rubber Latex ◽  
Microscopy Technique ◽  
Transmission Electron

Abstract An electron microscopy technique which has been used to visualize the crosslinked regions in vulcanized blends of dry rubber has now been applied to films made from natural rubber (NR) latex. The method involves swelling the latex film with styrene, polymerizing the styrene, sectioning the sample and then staining with osmium tetroxide to reveal the rubber network when observed by transmission electron microscopy (TEM). The micrographs show the higher ratio of interparticle to intraparticle crosslinks in a sulphur post-vulcanized film as compared with a sulphur prevulcanized film. They also show that, as in dry rubber films, the mesh size of the visible rubber network correlates with the crosslink density of the rubber. The technique also reveals that the crosslink distribution in peroxide prevulcanized latex (PPVL) is significantly different from that in latices prevulcanized using sulphur or radiation.

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.

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.

Mechanical capabilities and fire endurance of natural rubber latex modified concrete

2011 ◽  
Vol 38 (6) ◽  
pp. 661-668 ◽  
Author(s):  
Mohammad Ismail ◽  
Bala Muhammad ◽  
Abdirahman Ali Yussuf ◽  
Zaiton Majid ◽  
Mohamed ElGelany Ismail
Keyword(s):  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Comparative Investigation ◽  
Latex Film ◽  
Endurance Capacity ◽  
Rubber Latex ◽  
Critical Limit ◽  
Standard Fire ◽  
Fire Endurance ◽  
Temperature Levels

Compressive, indirect tensile, and flexural strengths characteristics of natural rubber latex modified concrete (NRLMC) were studied and reported — Part I. In addition, a comparative investigation between normal concrete (NC) and NRLMC, conducted on fire endurance was also presented — Part II. Normal and modified elements containing latex–water ratios within 0–10% were prepared and cured in accordance with the Japan Industrial Standard. Fire endurance capacity was assessed at five temperature levels; ambient temperature (27 °C), 150, 300, 500, and 800 °C. However, elevated heating (800–1300 °C) was further applied for the purpose of monitoring behavior at the verge of disintegration. Specimens were allowed to cool in the oven prior to compressive strength tests until room temperature is attained. Test results indicate that significant mechanical capabilities could be achieved by the inclusion of an appropriate quantity of latex concentrate and proper selection of befitting curing regime. Interestingly, the superiority of NRLMC over NC is maintained even under fire, up to the critical limit of latex-film capability performance.

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