Iranian Journal of Polymer Science and Technology
Year:2004 | Volume:17 | Issue:1 (ISSUE NO. 69)|Papers Count:7

With the aim of reducing the weight of vehicle and energy consumption, manufacture of composite leaf spring, containing continuous fibers in resin matrix, is under consideration. In this research, a composite leaf spring suitable for Nissan Patrol vehicle was designed and manufactured. In the first step, dimensional optimization was carried out in regards to constant bending stress and cross-sectional area throughout the length of the spring. Then, the composite leaf spring was made from glass fibers and epoxy resin, by hand lay up method. Comparing the composite leaf spring with the similar metallic type based on standard static test and field test, shows some advantages such as; weight reduction of 79.5%, competitive performance and passenger ride comfort.

In this research HIPS/HDPE blends were prepared and the effect of blend composition, polyethylene type and various compatibilizers on the rheological behavior of those blends was evaluated. Flow curves of the blends are intermediate to homopolymers. The viscosity-composition dependence of both blends show negative deviation with respect to mixture law. Replacing simple HDPE by MA functionalized HDPE and also addition of EVA and SEBS lead to increasing the blend viscosity and decreasing deviation from the additivity rule.  

In this research, the 3D conduction heat transfer equation was solved by the use of standard Galerkin technique and the finite element model equations were obtained. Based on this model, a computer code was developed in Visual Basic Language for Windows operating system. In this code, the calculation of the state-of-cure and rate-of-cure was also considered. Two curing kinetic models (n-th order and Kamal & Sourour) were selected. In order to show the applicability of the model and computer code, the temperature profile inside a rubber article during the curing process was compared with the experimentally measured data. Comparison showed that there is a very good agreement between the model predictions and actual data.

In this research report, doping of polyaniline with chiral camphorsulphonic acid, mandelic acid and tartaric acid has been investigated by UV-Vis spectroscopy.Appearance of absorption peak at 800nm and absence of absorption peak at 600 nm indicate that these acids can dope polyaniline shifting the position of absorption peak to lower wavelength in the case of tartaric acid and camphorsulfonic acids again mandelic acid indicated that interaction of these acids are stronger than mandelic acid with polyanilineo. Also increasing the acidity of these acids, the absorption peak at 800 nm became sharper.

The response of rubber compounds to a given stress (strain) depends not only on viscoelastic properties of base rubber,but also on the presence of additives.Among these additives, carbon black severely affects the viscoelastic properties because of strong interactions arising between the rubber and carbon black particles. In this research, uncured SBR 1502 compounds with various types of carbon black were prepared in Hake intern mixer and studied using RPA 2000 (Rubber Process Analyzer). Variations of viscoelastic parameters like G' , G" and tanδ with strain were determined for SBR 1502 compounds filled with different types of carbon black and  were  investigated. It was observed that carbon black with smaller particles have a higher reinforcing character, which depends to a large extent on the strain degree. Results showed that modulus of compounds having smaller carbon blacks particles reduces sharper than that having larger particles. All types of carbon blacks showed an increasing trend for tanδ as strain increases. Also theoretical modulus of carbon black filled compounds was determined using Einstein-Guth-Gold corrected equation that well fitted the experimental modulus.  

Resole resins can be cured at room temperature by using various amounts of organic or inorganic acids as curing agents. Application of acids as curing agents in processing of phenolic foams has a commercial importance due to its economic aspects. Therefore, they are more profitable. In this research, resole resin was first synthesized. Then the effect of catalyst, pH, temperature, monomers mole ratio and the time of reaction were investigated in such a way to synthesize resoles which were enough active to react with these acidic curing agents and, therefore, they were able to produce heat for making phenolic foams.