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In this work, natural rubber (NR) and regenerated cellulose (cel II) latexes were co-coagulated and to the mixture epoxidized natural rubber (ENR) was added on a two-roll mill. The cellulose content was fixed at 20 phr while ENR content varied from 0 to 75 phr. The influence of ENR was studied through the cure characteristics, aging and dynamic-mechanical properties. The aging provides nanocomposites with better solvent resistance and increased tensile strength at ENR content of 25 phr. The results suggest that a new type of light-colored nanocomposites were obtained, which presented high mechanical performance and resistance to solvents.

Epoxidized natural rubber (ENR) samples of various epoxidation degrees were synthesized from natural rubber (NR) latex, and 25 mole% epoxide of ENR was used to prepare ENR room temperature-curable films for coating applications. The films were prepared from rubber solutions. Trimethylolpropane tris(2-mercaptoacetate) (TMP-SH) was used as a curing agent. The effect of the thiol additive on the tensile and thermal properties of epoxidized natural rubber (ENR) was investigated. For the sake of comparison, NR and TMP-SH-containing formulations were also prepared. It was observed that the addition of TMP-SH improved the tensile, thermal and swelling properties of ENR, indicating the formation of crosslinks. On the other hand, the addition of TMP-SH didn't improve the properties of NR, indicating the absence of reaction with TMP-SH. On the basis of data on the properties of the ENR films of this work it is demonstrated that these are appropriate for coating applications.

Poly(ethylene terephthalate) (PET) composites containing muscovite mica as reinforcing filler were prepared by melt mixing, and their molecular dynamics were investigated by low-field NMR. Spin-lattice and proton spin–spin relaxation times of composites containing different amounts of the filler from 2 to 15 wt% were evaluated and the results compared with pure PET. DSC showed that for systems containing muscovite mica in percentages above 2 wt% a high level of crystallinity is achieved. By proton spin-lattice relaxation studies, a slight decrease in the T1H is observed for the composites with filler content up to 8 wt% and a drastic decrease at the higher filler content (15 wt%). Changes in T1H were associated with the content of amorphous phase in the composite.

This work is concerned with the influence of mica in natural rubber compounds on properties such as Mooney viscosity, processability and rheological behavior. The amount of this filler was varied from 0 to 40 phr and the stabilized and totalized torques, specific and mechanical energies were determined in a HAAKE torque rheometer. The elastic torque (S′) and complex dynamic viscosity (η∗) were measured on a rubber processing analyzer (RPA). The results show that mica influences processability and rheological properties, by acting as a processing agent in natural rubber composites.

The influences of elastomer ratio and preparation mode on the degradation behavior of NR/BR Natural rubber and polybutadiene rubber blends were investigated by using non-isothermal thermogravimetric analysis (TGA). The activation energy for the degradation process was determined by using both the Ozawa and the Kissiger methods, none of them requiring the knowledge of the reaction mechanism. TGA shows that degradation of NR/BR blends takes place in two steps.

White rice husk ash (WRHA) and black rice husk ash (BRHA) were incorporated as filler in natural rubber (NR) compounds. A conventional vulcanization system (CV) was chosen and cure studies were carried out on a TI-100 Curometer at 150, 160, 170 and 180°C. From the rheometric data obtained at 150°C, a specific constant related to the filler structure was evaluated that allowed predictions on how the presence of filler would affect mechanical properties such as tensile and tear resistances, and hardness. Swelling behavior and examination of the fracture surface, which was carried out on a Scanning Electron Microscope (SEM), were used to get some idea on the interaction between the rubber matrix and the filler. WRHA showed a good reinforcing potential for NR compounds and catalytic effect upon vulcanization.

The blends of acrylonitrile-butadiene-styrene (ABS) and polycarbonate (PC) prepared on a Haake Torque Rheometer System 9000 were studied in order to investigate the effect of ABS addition on the flow properties of PC. The recorded data obtained from the rheometer were converted, into values of shear rate, shear stress, and viscosity, following the method suggested by Laguna. The viscosity of the blends was found to decrease with the shear rate according to the concept of pseudoplasticity. An improvement in the PC processability through the ABS addition was confirmed. Along with the possibility of yielding rheological parameters, this method seems to be an efficient way to enlarge the application of this instrument in the polymer industry.

Blends of polypropylene (PP) and acrylonitrile rubber (NBR) were prepared in a Haake 9000 Rheocord System. Two different phenolic resins were introduced into these blends and the effect of this third component on the mechanical properties was evaluated, as well as the relationship between the crystallization of the polypropylene matrix and the properties analysed.