Large amplitude oscillatory shear has been employed to study the nonlinear viscoelastic properties of three polymer melts. The resins studied included a DuPont high-density polyethylene, a Union Carbide low-density polyethylene, and a Dow polystyrene. The equipment used consisted of a small-gap, concentric cylinder rheometer with a controlled-speed motor unit and a rack-pinion, oscillating drive mechanism. The torque was monitored by means of a torquemeter based on magnetic stress anisotropy in a steel tube and the strain was monitored by means of a displacement transducer. A signal proportional to the rate of strain was generated by integrating the strain with respect to time. Strain amplitudes up to 10 and frequencies between 0.5 and 30 sec−1 were employed. For purposes of material characterization, plots of stress versus rate-of-strain are employed. This is a closed stationary curve. Its “openness” is an indication of elasticity and its deviation from an elliptical shape is an indication of nonlinearity. Three material functions, obtainable from these curves, are defined and used for characterization. The first function is the amplitude ratio; the second function is related to the extent of the elastic component of the response, and the third one is a measure of nonlinearity. It was found that the extent of nonlinearity in the response is primarily a function of the strain amplitude rather than the frequency. The amplitude below which the response is practically linear depends strongly on the molecular structure. The response of the high-density polyethylene was practically linear up to a strain amplitude of 10.

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Textile can be a potential microorganism's propagation site because it contacts with human skin endows optimal conditions combination of nutrient sources, temperature, and moisture which provides conducive environment for microorganism growth. Thus, the development of antibacterial textile is crucial to inhibit the growth of microorganisms for protection the health and safety of wearer. This review article focuses on several metal-based nanoparticles possess biocidal feature namely, Ag, ZnO, Cu based, TiO 2 , and other minor metals based such as iron based, CeO 2 , Au, SiO 2 , Ni, and Pt. The phenomenology of metal nanoparticles associated to the antibacterial effects and possible mechanisms of action against bacteria have been highlighted. This review also discussed the synthesis techniques and effects of incorporation additive materials of those metal-based nanoparticles to inhibit the growth of microorganisms. J. VINYL ADDIT. TECH-NOL., 00:000-000,

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This study aims to investigate the effect electron beam (EB) irradiation on the polypropylene/devulcanized sulfur cured rubber (PP‐DVC) compound. The PP‐DVC compounds were compounded using twin‐screw extruder and then compression molded into required shapes before irradiation begins. The gel content of all irradiated PP‐DVC compounds gradually increased with higher irradiation dose indicated that the presence of DVC plays an important role in crosslinking enhancement. The mechanical properties of PP‐DVC compounds were observed marginally higher at low irradiation dosages (≤50 kGy). However, higher irradiation dosages up to 200 kGy cause adverse effect to the PP‐DVC compounds. In addition, the application of low irradiation dosage could enhance the dispersion of DVC particles at 20 phr composition in PP matrix. This also found that the scanning electron microscopy (SEM) observation where the DVC particles dispersed better in PP matrix compared to that of nonirradiated samples. Further increment in irradiation dosages up to 200 kGy reduced the crystallinity caused by chain scissoring process could rupture the crystalline structure in PP matrix. It was also found that the wavenumber of the CH and CH2 groups for irradiated samples reduced at high irradiation dosages due to the formation of carbonyl group. POLYM. ENG. SCI., 59:1017–1027, 2019. © 2019 Society of Plastics Engineers