Effect of the vulcanization time and storage on the stability and physical properties of sulfur-prevulcanized natural rubber latex

2005 ◽  
Vol 97 (5) ◽  
pp. 1804-1811 ◽  
Author(s):  
K. K. Sasidharan ◽  
Rani Joseph ◽  
Shiny Palaty ◽  
K. S. Gopalakrishnan ◽  
G. Rajammal ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Physical Properties ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
The Stability ◽  
And Storage

Characterization of Lidocaine Transdermal Patches from Natural Rubber Latex

2013 ◽  
Vol 747 ◽  
pp. 103-106 ◽  
Author(s):  
Prapaporn Boonme ◽  
Hasleena Boontawee ◽  
Wirach Taweepreda ◽  
Wiwat Pichayakorn
Keyword(s):  
Drug Release ◽  
Natural Rubber ◽  
Physicochemical Properties ◽  
Rubber Tree ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Transdermal Patches ◽  
The Stability ◽  
Main Component

The mucous liquid of Hevea brasiliensis or Para rubber tree, called natural rubber latex (NRL), composes of cis-1,4-polyisoprene which can form a patch under suitable formulation. In this study, blank and 5% lidocaine-loaded NRL patches were formulated and then characterized for physicochemical properties as well as evaluated in vitro drug release and stability. The patches were observed for their appearances. Surface morphology of the patches was investigated using a SEM. XRD was employed to study the crystallinity of the drug, the patch, and the drug-loaded patch. The extractions of lidocaine-loaded patches were analyzed for drug contents by HPLC. In vitro drug release study was performed using modified Franz diffusion cells. The patches at initial preparation and after kept at 4, 25, and 45 °C for 3 months were investigated for the stability determination. The results suggested that NRL could be used as a main component in pharmaceutical transdermal patches with acceptable physicochemical properties. Lidocaine-loaded NRL patches provided desirable drug release but high storage temperatures could age the patches resulting in darken color and lower release amount.

Study on Thermal and Mechanical Properties of Natural Rubber Latex Modified by Trichlorobromomethane

2011 ◽  
Vol 295-297 ◽  
pp. 36-40
Author(s):  
Xiao Xue Liao ◽  
Shuang Quan Liao ◽  
Bing Tang ◽  
Ming Chao Luo ◽  
Yan Fang Zhao ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Storage Modulus ◽  
Loss Modulus ◽  
Natural Rubber Latex ◽  
Mechanical Analysis ◽  
Thermal And Mechanical Properties ◽  
Rubber Latex ◽  
Scanning Calorimetry ◽  
And Storage ◽  
Thermal Stability Of

Natural rubber latex (NRL) modified by holgonated addition with trichlorobromomethane was prepared. The thermal properties of modified NRL were analyzed by thermogravimetric analysis (TG/DTG),differential scanning calorimetry (DSC) and dynamic mechanical analysis(DMA). The results showed that the thermal stability of modified NRL was lower than NRL and the thermal degradation of modified NRL was two-stage decomposition. With increasing of stress frequency, loss modulus and storage modulus of latex increased,while loss modulus and storage modulus of modified latex decreased,compared with NRL.

Natural rubber latex foam production using air microbubbles: Microstructure and physical properties

2020 ◽  
Vol 260 ◽  
pp. 126916 ◽  
Author(s):  
Sanit Sirikulchaikij ◽  
Rungrote Kokoo ◽  
Matthana Khangkhamano
Keyword(s):  
Natural Rubber ◽  
Physical Properties ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Foam Production

scholarly journals INFLUENCE OF THE VOLATILE FATTY ACID CONTENT TO RADIATION VULCANIZED NATURAL RUBBER LATEX (RVNRL)

2012 ◽  
Vol 09 (17) ◽  
pp. 38-41
Author(s):  
Hugo David CHIRINOS ◽  
Sueli CARVALHO DE JESUS
Keyword(s):  
Fatty Acid ◽  
Natural Rubber ◽  
Acid Content ◽  
Volatile Fatty Acid ◽  
Fatty Acid Content ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Protein Layer ◽  
Physical Strength ◽  
The Stability

Natural rubber latex is a dispersion of natural rubber particles in water. These particles are coated with a protein layer which will stabilize the dispersion in water by forming an electric charge in the layer. Any different condition affecting this layer disturbs the stability of dispersion. Microorganism attack disturbs the protein layer and consequently the stability of the dispersion. By adding 1.2% by weight of NH3, the stability of the dispersion can be improved. The fresh latex was irradiated by Co-60 with irradiation dose of 10, 20, 30, 40 and 100 kGy. The results showed a relationship between the volatile fatty acid content (VFA, product from microorganism attack on carbohydrate) and the green strength or the physical properties of vulcanized film. Low VFA number showing a higher physical strength of the film either un-vulcanized or vulcanized. It appeared that the structure was responsible in yielding a good physical property of the film.

scholarly journals Pengaruh Konsentrasi Asam Sulfat (H2SO4) pada Hidrolisa Tongkol Jagung (Zea mays) Menjadi Nanokristal Selulosa sebagai Filler Penguat pada Produk Lateks Karet Alam

2019 ◽  
Vol 8 (2) ◽  
pp. 48-53
Author(s):  
Hamidah Harahap ◽  
Azwin Harfansah Nst ◽  
Ilhamdi Fujian Junaidi
Keyword(s):  
Sulfuric Acid ◽  
Natural Rubber ◽  
Physical Properties ◽  
Mechanical Test ◽  
Natural Rubber Latex ◽  
Spherical Shape ◽  
Rubber Latex ◽  
Hydrolysis Process ◽  
Cross Connect ◽  
Vulcanization Process

This research studied about the effect of concentrations sulfuric acid (H2SO4) on the hydrolysis process of corn cobs waste to manufacture of cellulose nanocrystal (NCC) which will be applied as fillers in natural rubber latex. This study began with a pre-vulcanization process of natural rubber latex at a temperature of 70 oC and followed by a vulcanization process at 110 oC for 10 minutes. The results of the testing of physical properties indicate that the higher amount of NCC loading will result in higher crosslinked denotes, while the results of testing the mechanical properties indicate that the maximum value is achieved at the loading of NCCs as much as 6 phr. The mechanical test results supported by the analysis of Scanning Electron Microscopy (SEM) showing the NCC have spread well. Characterization of the Transform Electron Microscope (TEM) shown  the resulting of NCC was spherical shape with the size of NCC produced for each concentration of sulfuric acid (H2SO4) 45%, 55%, and 65% respectively 57.65 nm; 28.43 nm; and 82.61 nm with an amount of each 0.849 g; 1,824 g; and 0.681 g. The mechanical and physical properties of the optimum natural rubber latex products occurred in the loading of nanocrystal cellulose with a number of 6 bsk, where the values ​​of cross-connect density, tensile strength, elongation at break, M200 and M300 were respectively 10.6234 2Mc-1x10- 5; 18.2 MPa; 780%; 2.23 MPa and 2.7 MPa.

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