Influence of Reaction Volume on the Properties of Natural Rubber-g-Methyl Methacrylate

Abstract

Graft copolymer of natural rubber and poly(methyl methacrylate) was prepared using CHP/TEPA redox initiators at 508C and a reaction time of 3 h. Various reaction volumes (i.e., 0.5, 100, and 200 L) were used to prepare the graft copolymer which was then characterized by Fourier transform infrared spectrophotometer and proton nuclear magnetic resonance spectrophotometer ( 1 H-NMR) techniques. It was found that conversion of monomer to polymer and grafting efficiency slightly decreased with increasing reaction volumes. Quantity of grafted poly(methyl methacrylate) was calculated based on the integrated peak areas of the 1 H-NMR spectra and quantitative analysis by extraction method. It was found that both techniques gave similar level of the grafted poly(methyl methacrylate) onto the natural rubber backbone. Furthermore, Mooney viscosities, glass transition temperature (T g ) and degradation temperature (T d ) of the natural rubber and poly(methyl methacrylate) were slightly decreased with increasing the reaction volumes.

Improvement of Thermal and Mechanical Properties of Vietnam Deproteinized Natural Rubber via Graft Copolymerization with Methyl Methacrylate

“…Thus, it is clear that the MMA grafting improved the thermal stability of the DPNR. This observation is in agreement with the thermal degradation of modified natural rubber with other vinyl monomers [5,32,34,38,39].…”

“…These can be attributed to the methyl, methylene, and unsaturated methine protons of cis-1,4-isoprene units, respectively [33,34]. On the other hand, an additional signal at about 3.58 ppm was assigned to the protons of O-CH 3 of the grafted PMMA [27].…”

Influence of grafting content on the properties of cured natural rubber grafted with PMMAs using glutaraldehyde as a cross‐linking agent

“…A known weight of graft copolymer latex was first dried to a constant weight at 80°C for 24 hr. The dried weight was then used to calculate a percentage of monomer conversion into polymer using the following equation; [2,23] Ammonia + Glutaraldehyde → Pentane − 1,5 − diylidenediamine Pentane − 1,5−diylidenediamine + Natural Rubber The graft copolymer latex was first coagulated and then dried in a hot air oven at 40°C for 24 hr to remove the residual monomer. Soxhlet extraction method was used to extract unreacted NR and PMMA.…”

“…homopolymer) was later extracted using acetone for 24 hr and dried at 40°C. The grafting efficiency was calculated using the following equation [2,23] based on the weight difference before and after extraction;…”

“…For 1 H-NMR analysis, NRg-PMMAs were dissolved in CDCl 3 and then characterized by the 500 MHz NMR spectrometer (Varian, Germany). The mole and weight percentages of grafted PMMA on NR molecules were calculated based on the integrated peak area corresponding to methoxy protons (-OCH 3 ) of grafted PMMA and olefinic proton (=CH-) of NR, using the following relationships: [11,23] where A is the area under the curve for the peak of olefinic proton of NR; B is the area under the curve for the peak of methoxy proton of PMMA; C is the mole percentage of PMMA in the copolymer; C ′ is the molecular mass of repeating unit in PMMA; D is the mole percentage of NR in the copolymer; D ′ is the molecular mass of repeating unit in NR.…”