Influence of Different Copolymer Based Compatibilizers on Performance of Pristine and Recycled PP/PE blends (original) (raw)

Effect of Model Pollutants on the Recycling of PE/PS Plastic Blends

Progress in Rubber, Plastics and Recycling Technology, 2003

PE/PS blends have been extensively studied with the objective of improving their recycling. The objective of the present study was to investigate the effect of potential pollutants on properties of high density polyethylene (HDPE)/polystyrene (PS) plastic blends. The pollutants selected were a polar molecule of low molar mass, i.e. ethylene glycol, and an oil for engine which can be considered as less polar higher molar mass molecules. Such study can be considered for the recycling of polymer wastes from automotive applications. The compatibilizer used for PE/PS blends was a non-grafted Styrene-Ethylene Butene-Styrene copolymer (SEBS). Rheological properties, morphology and mechanical properties were analyzed. Study of the morphologies and of the mechanical properties shows that a small polar molecule such as ethylene glycol can form a third phase whereas an oil can improve compatibilization (lower diameter of the dispersed phase, better adhesion). Morphologies are in good agreement...

Compatibilization of PE/PS and PE/PP blends. I. Effect of processing conditions and formulation

Journal of Applied Polymer Science, 2003

The objective of this work was to study the effectiveness of low-cost commercial compatibilizers and several processes (internal mixer, single-and twin-screw extruders) for two types of plastic blends: high-density polyethylene/polypropylene and high-density polyethylene/ polystyrene blends, to gain insight into the recycling of wastes from those frequently encountered mixed plastics. Blends going from a pure A to a pure B component, with and without a compatibilizer, were prepared using an internal mixer, a corotating twin-screw extruder, as well as a single-screw extruder to follow an industrial-convenient process. In both cases, the analyses of blend morphologies highlighted the poor adherence between the two phases in the uncompatibilized blends. Compatibilized blends display better adherence between phases and the ability to process blends made from both single-and twin-screw extruders. When adding a compatibilizer, the viscosity of each blend (PE/PP or PE/PS) increased due to a better adhesion of the phases. Charpy impact tests showed that the presence of the compatibilizer in PE/PS blends increased their impact properties. Indeed, the improvement of the adhesion between the two phases enabled stress transfer at the interface. A singlescrew extruder seems to be efficient as a processing method on an industrial scale when a compatibilizer is used.

Addition compatibilization of PP/PS blends by tailor-made copolymers

Polymer Engineering & Science, 2006

The thermoplastic polymer blends of commercial interest generally need a phase compatibilization to reduce the interfacial tension, to stabilize the morphology, and to increment the interfacial adhesion. This work deals with the compatibilization of PP/PS blends by addition of a tailor-made copolymer, which is prepared from the pure homopolymers by a Friedel-Crafts reaction. This addition compatibilization process comes out as an economic alternative applicable to the recycling of mixed plastics from urban and industrial wastes. The influence of compatibilizer concentration and blending time on the emulsifying effect, morphology, and mechanical properties of the resulting blends are analyzed. The compatibilization process effectiveness is assessed through the improvement in phase adhesion, emulsification and ductility of the compatibilized with respect to the physical blends. An increase of three times in ductility is achieved using very low compatibilizer concentrations (0.5-0.7 wt%). No appreciable detriment in yield strength or modulus is observed in these compatibilized blends. POLYM. ENG. SCI., 46:329 -336, 2006.

Non-isothermal crystallization and melting behavior of compatibilized polypropylene/recycled poly(ethylene terephthalate) blends

European Polymer Journal, 2007

A highly novel nano-CaCO 3 supported bnucleating agent was employed to prepare b-nucleated isotactic polypropylene (iPP) blend with polyamide (PA) 66, b-nucleated iPP/PA66 blend, as well as its compatibilized version with maleic anhydride grafted PP (PP-g-MA), maleic anhydride grafted polyethylene-octene (POE-g-MA), and polyethylene-vinyl acetate (EVA-g-MA), respectively. Nonisothermal crystallization behavior and melting characteristics of b-nucleated iPP and its blends were investigated by differential scanning calorimeter and wide angle X-ray diffraction. Experimental results indicated that the crystallization temperature (T p c ) of PP shifts to high temperature in the non-nucleated PP/PA66 blends because of the a-nucleating effect of PA66. T p c of PP and the b-crystal content (K b ) in b-nucleated iPP/PA66 blends not only depended on the PA66 content, but also on the compatibilizer type. Addition of PP-g-MA and POE-g-MA into bnucleated iPP/PA66 blends increased the b-crystal content; however, EVA-g-MA is not benefit for the formation of bcrystal in the compatibilized b-nucleated iPP/PA66 blend. It can be relative to the different interfacial interactions between PP and compatibilizers. The nonisothermal crystallization kinetics of PP in the blends was evaluated by Mo's method.

Effect of a thermoplastic elastomer compatibilizer (sebs-g-mah) on the properties of PP/PET blends

2018

Polyethylene terephthalate (PET) and polypropylene (PP) are widely used and frequently encountered in domestic and industrial plastics, especially in the soft drink bottles. In the present work, different compositions of PP/PET blends were prepared and compatibilized by various contents of SEBS-g-MAH. The compatibilizing efficiency was examined using macro-(tensile and impact strength) and micro-mechanical testing (microhardness measurement), differential scanning calorimetry (DSC), wideangle X-ray scattering (WAXS), and melt flow index (MFI) determinations. The results show that the addition of SEBS-g-MAH improves the processability and the toughness of these blends. The changes in the melting enthalpies (∆H m) of the PP and PET components and the decrease of MFI values in the compatibilized blends indicated enhanced interactions between the discrete PET and PP phases induced by the functional compatibilizer. The DSC crystallinity of each component depended on the blend composition, and was slightly influenced by the presence of the compatibilizer. In the samples subjected to compression molding, the WAXS crystallinity of PP component slightly decreased in the presence of increasing amounts of compatibilizer.

Quality assessment of recycled and modified LDPE/PP blends

Journal of Elastomers and Plastics, 2012

An experimental study was conducted to investigate the morphology, thermal and mechanical properties of recycled polyolefin blends with different prehistory modified with ethylene propylene rubber (ethylene-propylene diene monomer (EPDM)) using the differential scanning calorimetry (DSC), wide angle X-ray scattering, Fourier transform infrared spectroscopy (FTIR), scanning electron microscope and mechanical methods. The efficiency of the modification was investigated as a function of the modifier content in the range from 7 wt% to 15 wt%. DSC results show that the single polymers are not clean material and contain some quantity of another polyolefins. In the processing and exploitation conditions, there is an increase in imperfect crystals in the postconsumer waste polypropylene. FTIR provides clear evidence about the oxidative processes and mechanical destruction during exploitation and blending. The obtained results proved that the technological and postconsumer wastes could be successfully reused as blends by the addition of EPDM.

Effect of Hard Plastic Waste on the Quality of Recycled Polypropylene Blends

Recycling

The recycling of plastic waste is undergoing fast growth due to environmental, health and economic issues, and several blends of post-consumer and post-industrial polymeric materials have been characterized in recent years. However, most of these researches have focused on plastic containers and packaging, neglecting hard plastic waste. This study provides the first experimental characterization of different blends of hard plastic waste and virgin polypropylene in terms of melt index, differential scan calorimetry (DSC), thermogravimetric analysis (TGA), mechanical properties (tensile, impact and Shore hardness) and Vicat softening test. Compared to blends based on packaging plastic waste, significant differences were observed in terms of melt flow index (about 10 points higher for hard plastic waste). Mechanical properties, in particular yield strain, were instead quite similar (between 5 and 9%), despite a higher standard deviation being observed, up to 10%, probably due to incomp...

Thermo-mechanical characteristics of thermally aged polyethylene/polypropylene blends

Materials & Design, 2010

Polyethylene (PE), polypropylene (PP) and their blends have attracted a lot of attention due to their potential industrial applications. Therefore, the current work has been carried out with the main objective of investigating the impact of the thermal aging/treatment and blend ratio (composition range) on the mechanical (tensile and hardness) and thermal characteristics (using thermogravimetric analysis in a dynamic air atmosphere) of PE, PP and PE/PP binary blends. Samples of PE/PP blends containing 100/00, 75/25, 50/50, 25/75 and 0/100 wt.% were prepared via injection moulding technique and thermally treated/aged at 100°C for 0, 2, 4, 7, 14 days. The tensile measurements indicated that the yield strength and the modulus decrease with increasing PE content. It was also observed that PE, PP and their blends deform in ductile modes. They undergo a uniform yielding over a wide range of deformation, which is followed by strain hardening and then failure. The strain to break for pure PE is found to be much higher than that for pure PP and for their blends, intermediate values have been observed. The hardness measurements have also revealed that increasing PE content in PE/PP blends reduced the hardness value of PP, however, thermal aging at 100°C has not affected the polymers hardness which holds also true for the tensile properties, showing a good correlation between tested mechanical properties. The thermogravimetric analysis (TGA) in a dynamic air atmosphere and derivative thermogravimetric analysis (DTA) were conducted to study the thermal degradation and stability of thermally unaged and aged PE, PP and PE/PP blends in terms of the initial (T d and T d(1%)) and final (T d(99%)) decomposition temperatures and maximum decomposition rate temperature (T max). All polymers start to decompose at no less than 365°C. As for mechanical properties, the blend ratio has affected the thermal properties however, aging time has not.