Design optimisation of collapsible PET water fountain bottles

Abstract not available

Degradation of low-density polyethylene over modified zeolites

The potential of catalytic processing as an effective method for polymer recycling was studied using various modified zeolites catalysts in the degradation of low-density polyethylene (LDPE). Particular attention was paid to catalytic activity, and selectivity and yield of liquid products. Two types of catalysts were evaluated: acid catalysts (HX and HY), and, pure NaX and its base-modified derivatives (NaX impregnated with MgO, CaO, SrO and BaO). As a benchmark, thermal degradations were performed at 623 K, 673 K, 698 K, and 723 K, to identify optimum operating conditions for the catalytic reactions. Thermal degradation at 623 K showed no conversion during the first 7 hours run, while at other temperatures conversion was 100% and liquid yields at 673 K, 698 K, and 723 K were 21, 77 and 80wt% respectively. Catalytic cracking tests were performed at 673 K to improve liquid yield, and showed significant increases in the following catalyst order: HX (50wt%) > HY (40wt%) > modified NaX (33wt%) > NaX (30wt%) > thermal (21wt%)

Influence of polypropylene content on the properties of post recycled high density polyethylene

Polypropylene (PP) from bottle caps is present in High Density Polyethylene (HDPE) in post consumer recycled resin, and it acts to reduce the overall toughness. This study is concerned with quantifying the influence of PP on the physical properties of recycled HDPE resins and evaluating toughening recycled HDPE/PP blends by the addition of metallocene catalysed linear low density polyethylene (m-LLDPE). The toughness of HDPE was found to decrease significantly with as little as 5 wt% PP, and at 20 wt% the toughness was reduced to levels comparable to that of PP alone. The addition of m-LLDPE was effective in increasing the toughness of the blends to values comparable or greater than those of recycled HDPE alone. The principal mechanism seems to arise from the suppression of crystallinity of HDPE matrix for levels of up to 20% m-LLDPE, and the introduction of amorphous phase content within the samples

Thermal and mechanical properties of recycled PET and its blends

This paper discusses the thermal and mechanical properties of virgin PET, recycled PET and their blends. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to study the thermal properties. The tensile tests at ambient and elevated temperature were used to study the mechanical properties. There were significant differences in the recrystallization behaviour as far as the thermal properties were concerned. In the case of mechanical properties, the tensile test at elevated temperature showed that the strength of the blends of recycled PET/virgin PET were lower than those ones of virgin PET

Thermal and melt rheological behaviour of composites produced from waste paper and plastic

The thermal and melt rheological properties of highly filled polymer composites produced from waste papers, Recycled Paper Waste (RPW) and Liquid Paperboard (LPB), in a post-consumer Stretch-Wrap (SR) matrix have been evaluated. Thermal testing has indicated that large amounts of absorbed water are bound to the filler and, along with small levels of volatile emissions, would be released in compounding and moulding of the composite. The thermal limits of the waste paper fillers and matrix have been evaluated, indicating upper processing limits in the order of 240°C. Melt rheological testing has shown large increases in viscosity with filler volume fractions that have shown a good fit to an exponential equation. The frequency dependence of the viscosity of the composites has shown good agreement with the power-law relation and the composites have shown a decrease in relative change in viscosity with temperature compared to the unfilled matrix

Degradation of low-density polyethylene over modified zeolites

Abstract not available

Catalytic conversion of low-density polyethylene into liquid hydrocarbons

Abstract not available

Low-cost composite materials from post-consumer plastics and waste paper

Composites of post-consumer plastics and high volume fraction waste paper have been studied. Various production techniques have been tested, with an optimum processing method defined, allowing the manufacture of low-cost composites of up to 60% paper content. Results indicate increases in tensile, flexural and creep modulus and flexural strength compared to the matrix can be achieved without the requirement of additives, with only marginally lower tensile strength and brittle impact behavior