Journal of Plastic Film & Sheeting

Different weight ratios of poly(3-octyl thiophene) / polyvinyl chloride blends were prepared using the casting method by dissolving poly(3-octyl thiophene) and polyvinyl chloride polymers in chloroform and Tetrahydrofuran, respectively. Fourier transform infrared spectroscopy indicates the existence of carbonyl group in both polyvinyl chloride neat and poly(3-octyl thiophene)–polyvinyl chloride blends. Electrical measurements reveal that the impedance values are increased with the increasing of both weight fraction of poly(3-octyl thiophene) and temperature. Optical results reveal that the increase of poly(3-octyl thiophene) weight fraction in blends enhances the UV-visible absorption of polyvinyl chloride and reduces the optical energy gap of blends. Differential scanning calorimetric measurements and thermal gravimetric analysis show that the glass transition temperature value and thermal stability of blend increases with increasing of poly(3-octyl thiophene) weight ratio. The obtained results, generally, indicate that the increase of poly(3-octyl thiophene) weight fraction enhances the interaction between poly(3-octyl thiophene)–polyvinyl chloride chains and as a result will restrict the chain mobility of polymers.

Polypropylene nanocomposites were melt blended and analyzed for both high shear and low shear rheology. Rheological characterization carried out at high shear rates showed lower viscosity values for the nanocomposites compared to the neat polypropylene. Complex viscosity values at low shear rates have shown an increasing trend on increasing nanoclay content. Zero-shear viscosity was found to increase with nanoclay loading. Steady rate sweep test results showed shear thinning of polypropylene and nanocomposites occurring in three steps. First normal stress difference showed higher values for 5 phr nanocomposite up to intermediate shear rate and subsequently lower values. Extensional viscosity experiments were carried out at different strain rates of 0.001, 0.01, 0.1 and 1 s⁻¹. Polypropylene nanoclay samples showed better strain-hardening behavior compared to that in neat polypropylene. Polypropylene nanocomposites blown films prepared at different nip-roll speeds were characterized for their tensile properties and film in-homogeneity.

Models developed by DuPont or reported in the literature are described, which help the package engineer to design new package structures by optimizing package performance, minimizing cost, and ensuring the film or laminate can be fabricated on converting equipment. A case study is presented to illustrate how the use of these tools can speed up new package development.

The heteroaromatic azo-polymer poly(azo-thiourea) has been prepared using 4-(4-aminobenzyl)benzenamine and diazonium salt solution of 2,6-diaminopyridine. The polymer was processable using polar organic solvents and had high molar mass of 62 × 10³ gmol⁻¹. Various concentrations of azo-filler were blended in solution phase using tetrahydrofuran or dimethylformamide with poly(styrene–butadiene–styrene). Morphology, thermal, and mechanical properties of styrene–butadiene–styrene/poly(azo-thiourea)blends have been studied using field-emission scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry, and tensile tests. Field-emission scanning electron microscopy micrographs of styrene–butadiene–styrene/poly(azo-thiourea) blends revealed fine granular filler dispersion in the matrix and development of conducting pathways. Accordingly, filler content from 10 to 60 wt% increased the conductivity from 0.99 × 10⁻¹ to 1.61 S cm⁻¹. A relationship between poly(azo-thiourea) loading and thermal stability of the materials was evident. Temperature for 10 wt% thermogravimetric weight loss increased from 467℃ to 483℃, while glass transition was enhanced from 151℃ to 155℃. Thermal and conductivity properties showed better results relative to pristine elastomer but less significant than the conducting filler used. Tensile properties were also dependent on the solvent used. In the dimethylformamide cast system, elongation at break was 345–387% versus the tetrahydrofuran system at 33–38%. The dimethylformamide cast blends tensile modulus was 599–769 MPa versus 876–1032 MPa for the tetrahydrofuran system. Thermal and conductivity behaviors were the same for both hybrid systems. Stress-induced birefringence in these blends has also been studied to find out the suitability of materials for waveguide applications.

This article reports on two polylactide composites obtained by melt compounding containing two silver-based biocide montmorillonites. The active clays are differentiated by the biocide agent oxidation state, i.e. in one sample silver is in ionic form and in the other as native nanoparticles. In both cases, composites with enhanced thermal stability and good dispersion and distribution of the antimicrobial compounds were obtained. The active engineered organoclays and the corresponding biocomposites showed strong antimicrobial activity against Staphylococcus aureus. The biocidal effect was larger for the ionic silver sample, as expected. The results support these composite material's potential as antimicrobial additives in polylactide active packaging applications obtained via melt compounding.