Waste PP Research Articles

Catalytic degradation of waste polypropylene by pyrolysis

Pyrolysis of PP waste has been carried out in a fixed bed reactor at 500°C. Basic salts (Na2CO3 and K2CO3), bases (NaOH and KOH) and Lewis acids (AlCl3, ZnCl2 and FeCl3) were used as additives in the pyrolysis process. The effects of additives on both product distribution and oil compositions have been investigated. The products from pyrolysis of the waste PP with bases (NaOH and KOH) produced wax whereas basic salts and Lewis acids produced liquid products under identical conditions. The oil compositions from both the thermal runs and the runs with additives were found to be very similar. The identified compounds were mostly alkene, alkanes and dienes.

Materialy polimerowe o strukturze komorkowej

A detailed description, based on the literature, of the dependence of the foaming process on the type of applied polymeric materials with special reference to polyolefins (PE and PP) was initially presented in the introductory section of this paper. The scope of the work involved comparative studies on the foaming process of waste PE-LD and PP (linear and branched) performed with the aid of chemical foaming medium, and that of particular virgin polymers. Cell composites comprising of PP filled with wood flour (filler-polymer weight ratio = 30:70) were also manufactured. A description of the applied foam extrusion system (Fig. 1) and an evaluation of the thermal decomposition of the blowing agents (Figs. 2 and 3) was made. The dependence of the structure of the polymer and composites obtained in the foaming process on the various reactive extrusion conditions such as the presence of talc as an auxillary medium, pressure, screw rotational speed, the application of a calibrator, the position of sampling for studies (outer part or middle) or the introduction of foam screen was also determined (Figs. 4-10, 13, 18-22). The viscosity curves (dependence of viscosity at 190°C on the strain rate), melt viscosity of the polymers and composites (Figs. 11, 14, 16) were discussed. Some applicability-related parameters of PP in its bulk and foamed composites such as density, stress, heat distortion temperature (HDT) and thermal conductivity (Figs. 23—25, Table 1) were compared. In the presented studies, porous low-density (0.5—0.6 g/cm 3 ) materials with good heat insulation properties suitable for applications especially in transport and construction were obtained.

Modification of Waste Polypropylene with Waste Rubber Dust from Textile Cot Industry and its Characterization

Waste plastics collected from municipality solid waste (MSW), were segregated, washed and dried. The fractions consisting predominantly of polypropylene were further segregated from the lot, cleaned and dried. These were chopped into pieces and then mixed in a Brabender Plasticoder with rubber dust from rubber textile cot industry at various proportions, till homogeneity is achieved. The tensile strength, impact strength and flexural strength of the blends were measured and observed that these properties increasing with increase in loading of rubber dust, reach a maximum at 10 wt% and then decreases. The dynamic mechanical properties of blends such as storage modulus, loss modulus and tan δ measured by DMA-2980 shows an increase in damping characteristics with an increase in the proportion of rubber dust. The rubber dust consists of blends of NBR and PVC used in making textile cots in the textile industry after vulcanization. It is observed that 10% of rubber dust imparts better strength properties with waste PP. The dispersion of the scrap rubber dust in PP has been analysed under SEM and its compatibility has been studied.

The Effect of GFR (Glass-Fiber Reinforcement) on the Composition-Property Balance of Compatibilized Recycled Polyolefinic Blends

The effect of 20% glass-fiber reinforcement on the composition-property balance of compatibilized HDPE (post consumer) and an industrial waste PP was investigated in a two-stage compounding process, using statistical design of experiments. Glass-fiber reinforcement strongly altered the physical properties of the compatibilized blend; it eliminated the previously observed [6] two factor interactions between HDPE and the Kraton rubber compatibilizer.