The fracture behavior of polypropylene/ethylene–propylene–diene terpolymer (100/8) blends with different microstructure was investigated using the essential work of fracture approach. Ethylene–propylene–diene terpolymer and dicumyl peroxide were mixed in a single-screw extruder at 140°C, and the crosslinking reaction had hardly taken place at this temperature. Then the reactive extrusion of ethylene–propylene–diene terpolymer and polypropylene was performed on a twin-screw extruder at a temperature range of 160–210°C and ethylene–propylene–diene terpolymer was crosslinked in this process. Various crosslinking density of ethylene–propylene–diene terpolymer in polypropylene/ethylene–propylene–diene terpolymer (100/8) blends was obtained by varying the concentration of dicumyl peroxide. With increasing dicumyl peroxide concentration, melt flow rate of the blends gradually increased but the increasing trend was slowed up. The degradation reaction of polypropylene was markedly restrained by adopting such a processing method. From the result of scanning electron microscopy, the size of ethylene–propylene–diene terpolymer particles was reduced and a more uniform particle size distribution was obtained. The existence of polypropylene/ethylene–propylene–diene terpolymer graft copolymer was demonstrated by differential scanning calorimetry and the negative effect of the graft copolymer on the crystalline rate of polypropylene macromolecules which were grafted onto ethylene–propylene–diene terpolymer chains was validated. The specific essential work of fracture (w_e) increased markedly with increasing dicumyl peroxide concentration for the blends prepared. When the concentration of dicumyl peroxide was 0.3 wt% of ethylene–propylene–diene terpolymer content, the value of w_e of the dynamic vulcanized blends was about 165% as that of polypropylene/ethylene–propylene–diene terpolymer simple blends or polypropylene, while the specific plastic work (βw_p) was still larger than that of polypropylene.

In this work mica or carbon black were used as filler in composites of acrylic rubber (ACM). The fillers differ not only in nature, mica being a mineral material and carbon black being organic, but also in form and particle size. The content of filler varied from 0 to 50 phr and its influence on ACM was evaluated based on cure parameters, mechanical, and swelling properties. The cure parameters allow the conclusion that the presence of mica does not have a negative effect on the cure or processability; the swelling results indicated a weak interaction between ACM and mica even though the mechanical properties of ACM composition with 40 phr of mica were found to be similar to those of 20 phr carbon black. As a result of mica being less expensive than carbon black, is light colored and easily processible, these properties are of industrial importance. All properties analyzed were compared with gum type composition (without filler).

To improve the wettability or hydrophilicity of the styrene–butadiene–styrene (SBS) triblock copolymer membrane using as transdermal patches, a series of graft copolymers were prepared by grafting hydrophilic monomers onto SBS membrane through ultraviolet irradiation technique. The characterization of the grafted membranes and the influence of various grafting factors on grafting percentage were studied. Infrared and X-ray photoelectron spectroscopy techniques were used to elucidate the surface properties of the grafted membrane. Scanning electron microscopy was used to observe the surface morphology of the grafted membrane. Experimental results showed that the grafting percentage and extent of grafting per area (mg/cm²) were about linearly increased with an increase of the molar ratio of hydrophilic monomer. In addition, the grafting percentage and extent of grafting per area for the grafted membranes were also approximately linearly increased with increase in irradiation time until 40 min. Decreasing contact angle and increasing equilibrium water content confirmed that the wettability of modified SBS membrane was improved.

The mechanical properties of brittle polymers are improved by blending with rubbers. Due to C=C in the rubber structure, polymer/rubber blends have poor thermal and oxidative resistance. In this research, the mechanical and physical properties including the morphology of poly(methyl methacrylate-co-styrene) sheet modified by blending with hydrogenated natural rubber were investigated. The optimum styrene content in copolymer sheets for improving the mechanical properties was 20% (w/w) and inclusion of hydrogenated natural rubber at 1% (w/w) exhibited a higher thermal resistance. This implies that hydrogenated natural rubber can be used as an impact modifier and thermal resistance improver for acrylic plastics.

Graft copolymer of natural rubber and poly(methyl methacrylate) was prepared using CHP/TEPA redox initiators at 50°C 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 (¹H-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 ¹H-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.