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Polyvinyl chloride/wood flour (WF)/organoclay (OMMT) ternary composites were prepared by melt blending. Chemically treated and untreated pine WF were used as filler, and organically modified montmorillonite or OMMT was added in order to get a potential synergy effect between polyvinyl chloride, untreated wood flour (UWF), or chemically treated WF. The OMMT loading in the composites was 0.5, 1, or 1.5 wt%. The chemically treated and UWF loadings were 1, 5, and 10 wt%. The composite specimens were subjected to mechanical tests (evaluation of tensile strength, elongation at break, and Shore A hardness), thermal stability (Beilstein test), processability characterizations, water resistance absorption, and morphological (optical microscopy) observations. The main results showed that the chemically treated WF were more efficient than the UWF for improving the mechanical and physical properties of polyvinyl chloride. Similar results were reported in the scientific literature. Therefore the chemically treated WF can be a cheap, eco-friendly, and renewable substitute for chalk as a filler which is normally used in the fabrication of Polyvinylchloride based cable insulators.

The objective of this research was to study the influence of thermal ageing and solvent resistance of a polypropylene (PP) and organoclay (OMMT) composite. This reinforced composite is a nanocomposite material and is generally used for the fabrication of automobile components and in the house construction parts. The loading of the organoclay was 1, 3, 5, 7 and 9 wt %. The composites were prepared by calendering followed by melt extrusion and subjected to mechanical testing, thermal ageing, solvent (toluene) resistance and optical microscopy observations. The results obtained showed that, before thermal aging, at 3 wt % OMMT loading, the tensile strength and hardness are maximal and the elongation at break is minimal. After thermal aging, at 5 wt % organoclay loading, the tensile strength is maximal and the elongation at break is minimal. The resistance towards toluene dissolution is maximal at 3 wt % of OMMT loading. The optical microscopy indicates the apparition of cracks at the interfaces broken samples and debonded organoclay agglomerates from polypropylene matrix induced by thermal ageing.

The literature relatively lacks results and data related to the direct influence of physical aging on the properties of polypropylene and natural rubber blend; so, the objective of this research was to study the influence of thermal and ultraviolet (UV) aging on a natural rubber (NR) SMR-ω and polypropylene (PP) blend. This toughened blend is generally used for the fabrication of automobile parts and in the construction industry. The loading of the NR was 10, 20, 30, 40 and 50 wt%. The blends were prepared by calendering followed by melt extrusion and it was subjected to XRD (WAXS) analysis, mechanical testing, thermal and UV aging, and optical microscopy (OM) observations. The results obtained by X-ray characterisation show that the adding of this kind of rubber does not affect the crystalline structure of the polypropylene matrix. Moreover, the adding of the rubber shows a decrease of the obtained material tensile strength and a valuable increase of the elongation at break. The shore A hardness decreases slightly as the percentage of the natural rubber increases. The optical microscopy indicates the apparition of cracks at the sample surfaces and debonded rubber domains from polypropylene matrix induced by UV and thermal aging.

This study addresses the problem of controlling by simulation the magnitude of the maximal catalyst temperature, or hot spot, in a four catalyst beds SO2 converter by manipulating the reaction mixture volumetric flow rate. The control of the maximal catalyst temperature is carried out in order to avoid the occurrence of a hot spot inside the catalyst mass and to keep high catalyst efficiency. Command algorithm used is the generalised predictive control (GPC) with off line process identification. The performance and robustness of the GPC controller are evaluated for the case of a kinetic complex and reversible exothermic reaction. The results obtained by numerical simulation show the possibility of the regulation of the hot spot temperature below a pre-specified value despite the occurrence of strong perturbations.