Water-Soluble Substance: Characteristics and Effects on the Properties of Natural Rubber Latex

2013 ◽  
Vol 668 ◽  
pp. 57-64
Author(s):  
Long Fei Fan ◽  
Shuang Quan Liao ◽  
Chao Qun Li ◽  
Xiao Xue Liao ◽  
Ming Wan Guo

Water-soluble substance is an important part of non-rubber substance in natural rubber latex and it has significant influence on the properties of natural rubber. The aim of this paper is mainly to study the composition of small-molecular-weight water-soluble substance (s-WSS) and its effects on the properties of natural rubber films. The analysis of IR and HPLC-MS showed that s-WSS (not including sugar) is composed of C3H4N4O6, C7H14O6, C11H13N3O5, C11H20O7 and C6H22N8. While the main component of s-WSS is C7H14O6 whichis a kind of alcohol. The tensile strength of the prepared composites can be increased at low loading of s-WSS. The tear strength of the prepared composites can be improved by adding s-WSS into natural rubber. The thermal oxidation degradation process of the samples has two stages. Compared with neat natural rubber latex, the initial degradation temperature was decreased significantly in both stages when s-WSS was added. While the degradation temperature range became larger in both stages.

2013 ◽  
Vol 675 ◽  
pp. 317-321
Author(s):  
Meng Ying Fang ◽  
Li Chun Liu ◽  
Fang Yin ◽  
Wu Di Zhang ◽  
Shi Qing Liu ◽  
...  

Using petroleum ether to extract the fermentative fluid (bio-slurry), then to get the inhibition mechanism of it, and infer which is the main component in inhibition mechanism of biogas. The conclusion found by the experiment is that fat soluble substance is better than water soluble substance in inhibition mechanism, and fat soluble substance is close to 75% biogas fermentation fluid, while water soluble substance is worst. That is to say, the main subject in inhibition mechanism is hided in the fat soluble substance.


2013 ◽  
Vol 747 ◽  
pp. 103-106 ◽  
Author(s):  
Prapaporn Boonme ◽  
Hasleena Boontawee ◽  
Wirach Taweepreda ◽  
Wiwat Pichayakorn

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.


2012 ◽  
Vol 482-484 ◽  
pp. 824-829
Author(s):  
He Ping Yu ◽  
Zong Qiang Zeng ◽  
Hong Chao Liu ◽  
Yong Yue Luo

Surface modifications of natural rubber latex films were carried out to improve the hydrophilicity by UV-induced immobilization of water-soluble butyryl derivative of chitosan using the photosensitive hetero-bifunctional crosslinking reagent, 4-azidobenzoic acid. The effects of the concentration of modified chitosan solution and UV irradiation time on the water contact angle values of natural rubber latex films were studied. ATR-FTIR analyses confirmed that the O-butylrylchitosan molecules were covalently bonded onto the surface of natural rubber latex film. The water contact angle value of natural rubber latex film which is about 95o reduces to 55o significantly with the introduction of O-butylrylchitosan. The results indicate that the hydrophilic behaviour of natural rubber latex film has been improved by immobilization of O-butylrylchitosan.


Author(s):  
Lawrence Edomwonyi-Otu

The present investigation deals with the determination of the physio-chemical properties of two commercial grade samples of local gums (Gum Arabic and Natural Rubber Latex (NRL)). The results revealed that the gum samples have high melting point that indicate thermal stability at room and moderate temperatures. The gum samples have about 95 % carbohydrate content and a corresponding high internal energy and can serve as a source of energy. The rheology of the samples revealed shear-thickening characteristics with gum Arabic being thixotropic and pseudo-plastic in nature while NRL was observed to be anti-thixotropic and rheopectic. Further results from the moisture absorption, contact angle and Fourier Transform Infrared Radioscopy (FTIR) analyses gave better insight into their hydroscopic behaviors. Gum Arabic has excellent water absorption capacity with less wettability as it consists mainly of more water-soluble compounds in comparison to Natural Rubber Latex. These insights from the study will enhance wider application of the gums with increased value-addition to the gums and the communities where they (can) thrive.


2015 ◽  
Vol 659 ◽  
pp. 458-462 ◽  
Author(s):  
Teerawan Wannuch ◽  
Adun Nimpaiboon ◽  
Jitladda Sakdapipanich

Natural rubber (NR) latex collected from Hevea brasiliensis rubber tree exists as a colloidal suspension with 30% dry rubber content (DRC). For convenient use and transportation, the latex is concentrated by centrifugation process. Through this process, the 60% DRC concentrated NR latex and 5% DRC skim latex as a by-product were produced. After using acid coagulation of skim latex, the skim rubber is obtained to use as a low-grade application due to high amount of non-rubber components as impurities. The water portion remaining after the coagulation of skim rubber consists of various water-soluble materials such as sugars, lipids, proteins and minerals, which can cause the water pollution if serum is directly discharged into the environment without proper treatment. However, 1.5% of L-quebrachitol was found in skim latex. It can be used in many applications such as a starting material for the synthesis of bioactive materials and inositol pharmacy. Thus, this work is an attempt to investigate the most effective extraction method of L-quebrachitol from skim latex. It was found that the appropriate solvent for extraction L-quebrachitol at high temperature and for recrystallization at low temperature is ethanol. The yield of L-quebrachitol about 2-3% by weight of solid serum was obtained. Moreover, a sweetness and antibacterial activity were also studied for its further applications. It was found that the sweetness of L-quebrachitol was twice than that of sucrose. No antibacterial activity of L-quebrachitol against Staphylococcus aureus and Streptococcus mutans was found.


2012 ◽  
Vol 626 ◽  
pp. 813-817 ◽  
Author(s):  
Z.M.F Tajuddin ◽  
A. Rashid Azura

Degradation for biodegradable natural rubber (NRL) films by Bacillus megaterium sp. is investigated. A common soil bacterium, Bacillus megaterium sp. is one of the largest eubacteria. This bacterium has large potential in degradation process for biodegradable natural rubber latex film. Specified method is used to cultivate the bacteria using suitable media. The growth of bacteria is studied through optical density and dry weight as a function of time. The optical density at specific wavelength with different stages of bacterial growth is used to determine their mid-log growth phase of the cell. The optimum time achieved to insert NRL films is between 17 to 20 hours of incubation period. Growth curve of Bacillus megaterium sp. gives an equation of Y=2.3401X. The biodegradation behaviour of Bacillus megaterium sp. is further investigated to access the viability as accelerating media for biodegradation of NRL films.


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