الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Since the earliest days of polymer technology many attempts were made to modify the character of polymers. Among the primary objectives sought for the modification of PVC were the improved mechanical properties and the thermal stability against light and heat and the increased heat distortion temperature.
A more efficient materials design can be achieved through the use of thermoelastic models. The use of accurate models aids in the understanding of the structural parameters controlling the thermal and mechanical properties and provides an insight into the reinforcement form and content necessary to achieve the desired property level. In addition, the use of models reduces both time and cost consumed in material design.
The first objective of this work was to review the different PVC composite systems: those proposed and those commercially used. The second objective was to discuss the most widely used mathematical models for the prediction of the properties of polymer-based composites. A third objective was the use of the composite model to predict the most important mechanical and thermal expansion properties of the isotropic PVC-glass composite system and the effect of the various structural parameters such as glass content, longitudinal aspect ratio, in case of fiber geometry and transverse aspect ratio in case of tape geometry on these properties. A final objective was the preparation of some specimens to check the validity of the used model.
A variety of PVC-composite systems cxis.1, in which PVC is combined with inorganic as well as cellulosic reinforcement with little attention focused on the PVC-g!ass system. The Composite model approach was proven to be superior to many existing modeling approaches. An attempt was made to examine the effect of the reinforcement structural parameters namely volume fraction, longitudinal and transverse aspect ratios on the isotropic composite modulus of elasticity and coefficient of thermal expansion using the composite-laminate model. The addition of glass to the PVC matrix has led primarily to an increase in stiffness values and to the decrease of the thermal expansion coefficient. The glass content has the dominating effect among all the other parameters, while the longitudinal aspect ralio has more influence than the transverse aspect ratio.The results were c,Jmpared to (plasticized)pPVC resin reinforced with chopped strand mat of different volume fractions. The prepared set of PVC-glass specimens showed an increase in tensile modulus and yield strength values with glass content. The percent elongation at break and ultimate tensile strength values decrease. The predicted stiffness values are in good agreement with experimental values.
The present study could be extended to verify model calculation using experimental work involving changes of aspect ratio. In addition, the failure mechanism of the composite needs further examination. Once established the work has to be extended to include anisotropic PVC-glass composite systems.