Papers by Keyword: Poly (vinyl chloride)

Abstract: Organic based stabilizers have been considered as a new technology providing environmentally friendly heat stabilizer for PVC pipe production to substitute conventional lead stabilizer as well as calcium zinc stabilizer. In this research, PVC samples stabilized with 5 types of heat stabilizers i.e. 1) commercial lead stabilizer, 2) commercial calcium zinc stabilizer, 3) commercial organic based stabilizer (OBS), 4) 1,3-dimetyl-6-aminouracil (DAU) and 5) eugenol, were investigated. From dynamic mechanical analysis, storage modulus at room temperature of PVC stabilized with DAU was found to provide the highest value among those stabilizers. Glass transition temperature of the PVC stabilized with all types of heat stabilizers was determined to be approximately 99°C except the value of about 89°C in eugenol stabilized PVC. Furthermore, PVC stabilized with commercial lead, calcium zinc stabilizer and commercial OBS could be reprocessed up to at least 5 cycles. Whereas, PVC stabilized with DAU was found to be able to withstand the processing cycle up to 4 cycles. Additionally, PVC stabilized with DAU showed the most outstanding short term thermal stability and can maintain its original color for at least up to 4 processing cycles. Finally, repeated processing of PVC stabilized with each type of heat stabilizers showed negligible effect on mechanical properties for at least up to 3 processing cycles. From the above results, it is evident that DAU showed high potential use as a safe and effective organic based heat stabilizer for PVC to substitute traditional lead or calcium zinc compounds.

Abstract: The graft copolymerization was carried out under nitrogen atmosphere using the free radical initiation technique. The blend formulations were first dry blended using a mixer before being milled into sheets on a two-roll mill at 170°C, and then hot pressed into composites specimens at 175°C for 10 min. The objective of this study to investigate the mechanical and thermal properties of PVC blends. The flexural strength and modulus of ungrafted composites increased with increasing filler content from 2 to 10 part per hundred resin (phr) while the grafted composites also increased only from 2 to 6 phr filler content. The flexural modulus of ungrafted was higher compared to the grafted composites whereas the grafted showed good flexural strength than ungrafted composites. The impact strength of both composites decreased with increasing filler content but the ungrafted composites showed good toughness than grafted composites. The thermal stability of both composites increased compared to unfilled PVC.

Abstract: The influence of the chemical structure both of polymer and plasticizer on the elasticity modulus has been analyzed. Consideration was made of the situation when the plasticized polymer is in the glassy or rubbery state. Description of the glassy state is produced basing on equation [1-2] containing the elasticity coefficient of atom bonds, the characteristic size of the bonds, and Van-der-Waals volumes both of the repeating units of polymers and molecule of plasticizer. Analysis for the rubbery state is based on the classic rubber elasticity theory. As a result the universal relationships are provided for description of the influence of chemical structure both of polymer and plasticizer on the modulus of elasticity.

Abstract: The theoretical analysis regarding the influence of the chemical structures both of polymer and plasticizer on the glass transition temperature has been produced. The analysis is made based on the Askadskii equation allowing T_g calculation of polymers. The phenomenon of blocking polar groups of the polymer by the molecules of plasticizer is taken into consideration. Also the effect of dilution was considered. The analytical expression for concentration dependence of the glass transition temperature is obtained, and a good agreement between the experimental and calculated data is provided.