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عنوان فارسی:
مدل سازی و مطالعه تجربی واکنش های کف سازی و ژل شدن پلی یورتان
عنوان انگلیسی:
Modeling and Experimental Study of Polyurethane Foaming and Gelling Reaction
Abstract
Numerous reactions take place within a polyurethane polymerization process. Homogeneous and catalytic reactions occur at the same time and intermediate compounds are formed. As the reaction proceeds, long chains of polymer are formed which drastically affect the kinetics of the reaction. Temperature and viscosity profiles of the reacting mixture are two strong indicators of the extent of reaction and the way the reactions are carried out. Therefore, simulating polyurethane gel and foam systems helps interpret temperature and viscosity profiles and gain insight into the kinetics of the system.
Using MATLAB program, a model was introduced which simultaneously solves over 80 ordinary differential equations and provide temperature and viscosity profiles as well as concentration profiles, degrees of polymerization, gel point and foam height for individual formulations.
عنوان فارسی:
درک اساسی توسعه آسیب های ناشی از خراش در پلیمرها
عنوان انگلیسی:
Fundamental Understanding of the Development of Scratch-induced Damages in Polymers
Abstract
Scratch performance of polymers is very important considering its wide range of applications in optical, automotive, electrical and household appliances where long term wear and tear of material is critical. The objective of this research is to study the scratch-induced damage in polymers using experimental study on model polymers and finite element method (FEM) modeling. Uniaxial tensile testing and scratch testing with variation in speed are carried out on acrylic and polycarbonate (PC) and the results are analyzed and discussed. Efforts are made to relate rate dependent mechanical behavior with the scratch behavior of polymers. Three-dimensional finite element method (FEM) modeling has also been carried out to simulate the crack formation during the scratching process. Effects of material and surface properties on scratch-induced damages in polymers have been investigated. The study provided useful insights on designing scratch resistant polymers.