Characterization of non-crosslinked natural rubber latex by phase transfer technique

Toughness and morphology of radiation‐crosslinked natural rubber modified polystyrene

“…The data obtained confirmed the presence of naturally polydispersed rubber particles in RVNR latex (11,12). As expected, the size of crosslinked rubber particles greatly increased after swelling in styrene monomer, which is a ‘good’ solvent of rubber 17, 18. The ratio of volume of RVNR particles in styrene monomer to that of rubber in latex was 4990%.…”

Applications of phase transfer technique to the study and development of natural rubber

“…For better understanding, this phase transfer technique was then extended to the study of DPNR latex (treatment of latex with alcalase enzyme). 8 Similar observations to the case of noncrosslinked NR were noted, i.e., after phase transfer of the DPNR latex particles, three phases were also noticed where the destabilized and suspended rubber at the organic solvent-water interphase still existed. This might be attributed to the remaining proteins in the DPNR latex, bonded to rubber chain, which could not be removed by the enzyme and the proteins were consequently denatured by added cationic surfactant.…”

“…7 It was observed that the transfer of rubber took place immediately where three phases were noted, i.e., the upper organic phase containing the soluble rubber, the destabilized and suspended rubber at the interphase between organic solvent and water, and the lower rubber-free serum aqueous phase. Molecular weight of the soluble rubber in the upper toluene phase (in the case where toluene was used as solvent), measured by viscosimetric method, was about 10 6 .…”

Novel method for toughening of polystyrene based on natural rubber latex

“…It can be explained that the highly crosslinked rubber particles would slightly swell in the styrene monomer and, consequently, expose less surface charges than those in the case of the lightly crosslinked. The higher the irradiation dose used, the lower the quantity of the added cationic surfactant for neutralization of the negatively charge on the surface of RVNR particles required and, hence, the decrease in CTC values 20…”

“…The key steps involve the use of γ ‐radiation vulcanized natural rubber (RVNR) latex/phase transfer/bulk polymerization. The phase transfer technique has been successfully used to transfer noncrosslinked, γ ‐radiation vulcanized and deproteinized NR latex particles from the aqueous phase into the styrene monomer phase 20–22. Not only the easily transfer behavior, but the RVNR latex also exhibits an ingredient‐free nature and the unaltered rubber phase morphology and particle size due to the crosslinked structure; hence, it was selected for our study.…”