PVC Rubber Research Articles

Improved collector design for the capture of tropical spiny lobster, Panulirus homarus and P. ornatus (Decapoda: Palinuridae), pueruli in Lombok, Indonesia

The literature on late-stage larval and puerulus settlement of tropical spiny lobsters suggests that a broad range of visually-assessed variables may play a role in the selection of settlement substrates. These variables include light level, luminosity, degree of exposure, and the availability of edges, crevices and clefts. A fishery has developed in Indonesia, that captures pueruli for grow-out purposes, along the entire southern coastline from Java to Sumbawa. The present study builds on knowledge gained on the behaviour and substrate preferences of settling pueruli by examining aspects of collector design and substrate surface characteristics in regard to catch rates. A series of tank-based experiments were used to examine preferences for various attributes of collector materials, and preferred material characteristics were then tested in a field experiment to verify the laboratory results. In the tank experiment the most preferred substrate was cement bag paper, followed by insect mesh, weed netting, PVC rubber and cement bag plastic. Crevice angles of 10° and 20° were significantly preferred over 30°. The substrate level and other substrates had less influence on settlement. However, both the lunar phase and type of materials tested in the field had a significant effect on settlement. Significantly greater numbers of pueruli were caught at the time of the new moon than at other moon phases. Cement bag paper was the most preferred material in the field, followed by cement bag plastic, insect mesh, weed fabric, and PVC rubber.

Synthesis and characterization of polymeric plasticizer from PET waste and its applications in nitrile rubber and nitrile–PVC blend

Polyethylene terephthalate (PET) waste is not biodegradable; thus, it will create environmental hazards if disposed in landfills. Therefore, the only way of addressing the problem of disposal of post-industrial and post-consumer PET wastes is through recycling. The polyester plasticizer for polyacrylonitrile butadiene rubber (NBR) and polyacrylonitrile butadiene–polyvinylchloride rubber blend (NBR–PVC) was obtained by the depolymerization of PET waste with 2-ethyl-1-hexanol. The PET waste was depolymerized until a polymeric plasticizer with the average molecular weight in the range of 450–900 g/mol was obtained. The polymeric plasticizer was characterized for acid and hydroxyl numbers, viscosity, density, FTIR, NMR and TGA/DTA thermogram. The prepared polymeric plasticizer was used in the preparation of nitrile rubber and nitrile–PVC rubber blend rubber sheets, where these sheets were tested for compatibility, tensile strength, elongation-at-break, hardness and ageing properties. Nitrile rubber and nitrile–PVC blend sheets were also prepared using DOP as a plasticizer and a comparative study with the synthesized polymeric plasticizer was made. It was observed that synthesized polymeric plasticizer provides excellent tensile properties and ageing resistance for high-performance applications as compared to that obtained from DOP. The end uses for nitrile rubber and nitrile–PVC rubber blend compounds are quite diverse, but they can be loosely categorized as being either general performances or higher performance applications. Each of these performance categories requires a different set of considerations in terms of compounding with plasticizers.

PVC–rubber blends. VI. The structure

AbstractThe dependence of the dynamic shear modulus of blends of polyvinyl chloride and rubber on the temperature and concentration of the rubber was investigated. For a calculation of a theoretical value of the modulus a formula recently derived by Uemura and Takayanagi was adopted. This formula is based on the assumption of a two‐phase system, in which one phase is a continual matrix and the other is discrete spherical particles, and of perfect adhesion between the phases. Most of the theories that clarify the part played by rubber in rubber‐modified vitreous materials are based on these assumptions. In most cases we have found a good conformity between the theoretical and experimental values of the modulus. In a certain system with an outstanding impact strength, however, a severe discrepancy has been found. This implies that the present structural explanation of the high impact strengths of two‐phase systems is not quite generally applicable.

Beziehungen zwischen den dynamischen Eigenschaften und der Schlagzähigkeit der Mischungen des Polyvinylchlorids mit Kautschuk

AbstractMeasurements of dynamic properties of a series of polyvinylchloride‐rubber blends at temperatures of −60 to +100°C and frequencies of 0.3–3.0 Hz have been carried out by means of the free vibration method. The dynamic data have been compared to the results of impact resistance Charpy‐experiments. The linear correlation obtained between the dynamic shear modulus at −10°C (G′−10) and the impact resistance at 20°C indicated that the value G′−10 has to be decreased compared to that of unmodified PVC to increase the resistance of compatible as well as incompatible PVC‐rubber blends. The impact resistance increases with higher decrease of G′−10. The correlation given and the breaking characteristics of the samples investigated show that, ductile fracture, relieving the deformational stress mainly by developing cracks, occurs in blends with G′−10 in the range of 12.0–7.5 × 108 N/m2. This is valid for compatible as well as incompatible PVC rubber blends.