The study of preparing silica/rubber composites used in tires with low rolling resistance in an energy-saving method is fast-growing. In this study, a novel strategy is proposed, in which silica was modified by combing alcohol polyoxyethylene ether (AEO) and 3-mercaptopropyltriethoxysilane (K-MEPTS) for preparing silica/natural rubber (NR) master batches. A thermal gravimetric analyzer and Raman spectroscopy results indicated that both AEO and K-MEPTS could be grafted on to the silica surface, and AEO has a chance to shield the mercaptopropyl group on K-MEPTS. Silica modified by AEO and K-MEPTS together was completely co-coagulated with the rubber in preparing silica/NR composites using the latex compounding method with the help of the interaction between AEO and K-MEPTS. The performance of composites prepared by silica/NR master batches was investigated by a rubber process analyzer (RPA), transmission electron microscopy (TEM) and a tensile tester. These results demonstrate that AEO forms a physical interface between silica and rubber, resulting in good silica dispersion in the matrix. K-MEPTS forms a chemical interface between silica and rubber, enhancing the reinforcing effect of silica and reducing the mutual friction between silica particles. In summary, using a proper combination of AEO and K-MEPTS is a user-friendly approach for preparing silica/NR composites with excellent performance.

https://www.mdpi.com/2073-4360/10/1/1/pdf

Silica Modified by Alcohol Polyoxyethylene Ether and Silane Coupling Agent Together to Achieve High Performance Rubber Composites Using the Latex Compounding Method

OBJECTIVE: To evaluate the antibacterial potential of aqueous and acetone extracts of galls of Quercus infectoria by determination of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values. 
MATERIALS AND METHODS: The extracts from the galls of Q. infectoria at 10 mg/ml were screened against three Gram-positive bacteria (Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis and Bacillus subtilis) and three Gram-negative bacteria (Escherichia coli NCTC 12079 serotype O157:H7, Salmonella typhimurium NCTC 74 and Pseudomonas aeruginosa ATCC 27853). The MIC of the extracts were then determined using the twofold serial microdilution technique at a concentration ranging from 5 mg/ml to 0.0024 mg/ml. The MBC values were finally obtained from the MIC microtiter wells which showed no turbidity after 24 hrs of incubation by subculturing method. 
RESULTS: Out of the six bacterial species tested, S. aureus was the most susceptible. On the other hand, the extracts showed weak inhibitory effect against S. epidermidis, B. subtilis, S. typhimurium and P. aeruginosa while there was no inhibition zone observed for E. coli O157. The MIC values of the extracts ranged from 0.0781 mg/ml to 1.25 mg/ml whereas the MBC values ranged from 0.3125 mg/ml to 2.50 mg/ml. The MBC values of aqueous extract against S. aureus and S. typhimurium were higher than their MIC values. The MBC value of acetone extract against S. aureus was also higher than its MIC value. Interestingly, however, the MIC and MBC values of acetone extract against S. typhimurium were the same (1.25 mg/ml). 
CONCLUSION: The aqueous and acetone extracts displayed similarities in their antimicrobial activity on the bacterial species and as such, the galls of Quercus infectoria are potentially good source of antimicrobial agents.

/pdf/research-paper-the-potential-of-aqueous-and-acetone-extracts-2q5wqo9bbd.pdf

Research Paper - The potential of aqueous and acetone extracts of galls of Quercus infectoria as antibacterial agents

Phytosterols and their derivatives: Structural diversity, distribution, metabolism, analysis, and health-promoting uses.

Current advancement on the isolation, characterization and application of lignin.

Investigating natural rubber composition with Fourier Transform Infrared (FT-IR) spectroscopy: A rapid and non-destructive method to determine both protein and lipid contents simultaneously

Lipids of fresh latex from three Hevea brasiliensis clones (RRIM600, BPM24, and PB235), and of sheet rubber produced from it, were extracted by an optimized method and characterized through various chromatography techniques. Total and free fatty acids, phospholipids, glycolipids, and the unsaponifiable fraction were analyzed for each clone. Qualitative and quantitative comparisons of total extractable lipids indicated a smaller amount in sheet rubber (2.31-3.28%?w/w dry rubber) than in fresh latex (3.36-3.67%). Partial hydrolysis during primary rubber processing, such as polar lipids, was found to be the main source of this loss. Alongside the effect of primary processing, the clonal origin of the trees was found to be the main factor for differences in lipid quantity and composition. Practical applications: Lipids are the main non-isoprene components in natural rubber (NR) and play many important roles in NR properties. Detailed knowledge of the lipid composition would contribute towards a better understanding of the structural and physical properties of NR. The lipid composition also appears to be sufficiently specific to consider its use as a new tool for tracing the clonal origin of NR. (Resume d'auteur)

Lipid compositions of latex and sheet rubber from Hevea brasiliensis depend on clonal origin

https://www.supagro.fr/plantlippol-green/Doc/Phytochemistry%202011.pdf

Glycolipid composition of Hevea brasiliensis latex

Antimicrobial kinetic activities of lignin from sugarcane bagasse for textile product

Non-isoprene components and especially lipids have been reported to be involved in some key properties of natural rubber. Unfortunately, these results are hardly comparable due to different extraction methods. This work aimed to optimize lipid extraction from natural rubber either in the liquid state (latex) or in the dry state (unsmoked sheets). Extraction of unsmoked sheets from the RRIM 600 clone was carried out with different combinations of organic solvents (chloroform/methanol and hexane/isopropanol mixes). Chloroform/methanol (2 : 1 vol/vol) was found to be the most suitable for lipid extraction from unsmoked sheet rubber. The lipid extraction yield was improved by increasing the exchange surfaces by grinding rubber under liquid nitrogen and extracting the ground rubber for 6 h at room temperature, leading to 1.82% lipid extraction yield (versus dry rubber). Concerning latex extraction, the problem of lipid entrapment in the coagulum from immediate coagulation of latex in the solvent was solved by preliminary two times dilution of latex, giving a 3.24% extract (versus dry rubber) containing a minimum quantity of contaminating polyisoprene. Concerning the nature of lipids, dilution increased mainly neutral lipid extraction, which may suggest that neutral lipids were those entrapped by coagulation. (Resume d'auteur)

Siriluck Liengprayoon

Papers

Investigating natural rubber composition with Fourier Transform Infrared (FT-IR) spectroscopy: A rapid and non-destructive method to determine both protein and lipid contents simultaneously

Lipid compositions of latex and sheet rubber from Hevea brasiliensis depend on clonal origin

Glycolipid composition of Hevea brasiliensis latex

Antimicrobial kinetic activities of lignin from sugarcane bagasse for textile product

Development of a new procedure for lipid extraction from Hevea brasiliensis natural rubber