MANUFACTURE AND CHARACTERIZATION OF POLYVINYL CHLORIDE / POLYETHYLENE PVC / PE COMPOSITES FOR STRUCTURAL APPLICATIONS

The research initially studied a safe recycling process that decreases the accumulation of thermoplastic wastes and prevents pollution of the environment. Obtained all composites in these works were analyzed for mechanical, thermal, and morphological dynamical- mechanical and rheological characteristics. This research aims to develop a new polyvinylchloride (PVC) microcomposite that incorporates low density polyethylene (LDPE), calcium carbonate (CaCO3), and calcium/zinc stearate (CaSt2/ZnSt2). The addition of 5 phr of CaSt2: ZnSt2 = 9:1 into PVC appears to yield an optimal mechanical result and shows high thermal stability. Moreover, when a heat stabilizer rich in calcium is mixed with CaCO3 and LDPE, an excellent synergistic effect is demonstrated. The properties of polyvinyl chloride (PVC) and low density polyethylene (LDPE) blends, at three different ratios (20, 50, and 80 wt.%) of renewable LDPE were studied. Besides, Biobased composite with PVC-LDPE blend and date palm fiber as reinforcement at different loading levels (0-30 wt.%) were also investigated. The matrix in which PVC-LDPE (20 wt.%-80 wt.%) had the optimum mechanical and thermal properties. The modulus of the composites is enhanced with increasing DPLF content. Scanning electron microscopic micrographs revealed that morphological properties of fracture surfaces are following the tensile properties of these blends and composites. Thermal analysis showed that the thermal degradation of PVC-LDPE (20 wt.%/80 wt.%) blend and PVC-LDPE-DPLF (10 and 30 wt.%) composites took place in two steps: in the first step, the blend was more stable than the composites. In the second step, the composites showed slightly better stability than the PVC-LDPE (20 wt.%-80 wt.%) blend. Leaflets and rachis fibers (DPFs) were used as a sustainable reinforcement material to strengthen PVC-HDPE (20:80) biocomposites to further study the feasibility of compounding date palm fiber. As this renewable material used in this project work are crop wastes, the fibers had to be pre-treated to eliminate lignin and impurities for enhancing the interfacial adhesion between matrix and fiber, composites with untreated and treated DPFs containing 30 wt% were produced. Infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA) have confirmed the enhancement of surface modification of DPFs from the delignification process to the extraction of cellulose microcrystals (CMCs). Furthermore, structural, morphological, thermal, mechanical, dynamic-mechanical, rheological, and water absorption all improved the biocomposites characteristic performances as a function of the modified DPFs. Hence, the PVC HDPE-HNO3F composite reveals a selective advantage to be a good potential candidate for several structural application

Thermophysical behavior of date palm fiber-reinforced polyvinylchloride /low-density polyethylene/acrylonitrile butadiene rubber copolymer ternary composite

Date palm tree leaf-reinforced polymer composites have important advantages, such as sustainability and lowcost. In the present study, ternary blend composites of polyvinyl chloride (PVC), low-density polyethylene (LDPE), and acrylonitrile butadiene rubber (NBR) copolymer (LDPE/PVC: C0, LDPE/PVC/NBR:C1) as well as reinforced composites with 10, 20, and 30 wt.% of alkali treated date palm fiber (TDPF) (C2, C3 and C4 respectively) were fabricated using a melt blending extrusion process. TDPF and the NBR copolymer were used to improve the interfacial bonding, compatibility, and thermo-mechanical properties of the composite, yielding the highest tensile strength of 32 MPa for the composite containing 10 wt.% TDPF. Moreover, the morphological analysis showed that the incorporation of the NBR copolymer enhanced the compatibility of the blend. Mechanical tests revealed that the hardness of the TDPF/PVC/LDPE/NBR composite increased in the order C2 (450 MPa) < C3 < C4 (540 MPa). In addition, the flexural and tensile moduli of the composite increased with increasing TDPF content, with the highest values (534 and 1585 MPa, respectively) observed for composite C4. Thermal analysis revealed increased Tonset and T10% values, indicating an improved thermal stability of the composite. This study clearly demonstrates that the (DPF/PVC/LDPE/NBR) composites can be used in various high-tech engineering applications, which require excellent properties

Effect of quenching temperature and filler rate on the mechanical thermal and physical properties of composites: Polypropylene/calcium carbonate

Polypropylene (PP) is a strong, tough, crystalline thermoplastic material with high performance. Because of its diverse thermo-physical and mechanical properties, it is utilized in a wide variety of disciplines. In this study, the impact of free quenching on the thermo-physical characteristics of PP/calcium carbonate (CaCO3) composites was examined. Three distinct heating procedures were used. First, composites were cooled from their melting phase temperature to ambient temperature. Second, composites were cooled from 130°C to a pre-determined and controlled temperature (T: 0°, 20°, 30°, 40°, 50°, 60°, 70°, 80°C). Third, composites were temperature-tested using annealing. The findings suggest that the elongation-at-break and impact strength may be improved following an initial quenching process from the melting phase to ambient temperature. On the other hand, a second quenching process at 0°C produces superior results, and a correlation between mechanical and thermal characteristics is noted; however, while these qualities are increased, others, such as flexibility, density, Vicat softening temperature (VST), and heat distortion temperature (HDT) are negatively impacted