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In this study, a blend of polypropylene (PP) and two types of thermoplastic polyolefin elastomers (TPO) were prepared by melt mixing. The TPOs were either ethylene- or propylene-based copolymer. The mechanical response and morphology of the blends were investigated using tensile and impact tests and scanning electron microscopy technique. There was significant increase in the impact strength of the TPO-modified PP, which was an outcome of fine dispersion of TPO inclusions. In particular, the blends containing PP-based TPO exhibited dramatic enhancement in toughness energy as featured by a plastic deformation in tensile test. The brittle-tough transition had several deviations from theoretical models, in which generally the interparticle distance criterion was realized as a single parameter, only controlled the transition of brittle to tough behavior. Moreover, the brittle-tough transition in tensile and impact mode tests was not coincident in the blend with a broad distribution of interparticle distance. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44068.

In this study, PVC/(wood flour) (WF) composites were prepared by using a counterrotating twin-screw extruder, and the effects on the mechanical properties of concentration and particle size of the WF, type and amount of coupling agent, K value of PVC, feed rate of extruder, and die temperature were investigated. Optimization of various formulation parameters based on the Taguchi method demonstrated that the wood content and wood particle size were the most important parameters. Flexural modulus increased upon increasing WF loading up to 50 wt%. Also, flexural strength and modulus increased with particle size because of the higher aspect ratio and better quality of mixing. Use of coupling agents had a minor effect that was attributed to the moderately high polarity of PVC causing relatively good compatibility between WF particles and the PVC matrix. The optimum level of WF calculated by considering the contribution factor was 50 wt%. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers

The incorporation of functionalized acrylonitrile–butadiene rubber (NBR) into recycled poly(ethylene terephthalate) (PET) was introduced as an effective route for modifying the properties of PET and as a new method for PET recycling as well. To achieve modified NBR, glycidyl methacrylate (GMA) was grafted onto NBR with optimized reactive mixing, in which the highest grafting degree and lowest gel content were generated. PET/NBR blends with and without GMA functionalization were produced by melt mixing, and the mechanical properties, dynamic mechanical thermal properties, and phase morphologies of the systems were determined and compared. We found that low amounts of peroxide initiator (dicumyl peroxide) and high levels of the GMA monomer in the presence of the styrene comonomer led to the maximum grafting degree and suppressed the competing rubber crosslinking and GMA homopolymerization reactions. The blend compatibility with PET determined from dynamic mechanical thermal analysis spectra and scanning electron microscopy images was greatly improved when the NBR-grafted GMA was used instead of the neat NBR in the blend recipes. As a result, the rubber phase dispersed in the PET matrix more finely, and the impact strength of the blend advanced very significantly. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40483.

This study focuses on the possibility of improving performance properties of polyamide-6 (PA6) nanocomposite films for packaging application using nanoclay masterbatch. Different concentrations of nanoclay in PA6 were prepared through melt-mixing of particulate nanoclay and nanoclay masterbatches in a twin screw compounder, then film samples were molded using a hot press. Oxygen barrier properties were then measured and interpreted on the basis of different theoretical approaches. Also, a correlation between morphology and properties of the studied nanocomposites was observed, and all prepared nanocomposites exhibited performance improvement with increasing the nanoclay content. The masterbatch-based nanocomposite films showed more exfoliated regions that leading to the enhancement of the mechanical properties. Gas permeability through nanocomposite films decreased significantly just by loading a small amount of nanoclay. However, surprising behavior in oxygen permeability observed at higher levels of nanoclay in masterbatch-based nanocomposite was attributed to the decreased crystallinity of PA6 matrix. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012