The effect of chain extender on the improvement of molecular structure and rheological properties in shear and elongation of recycled poly (ethylene terephthalate) was studied. The results suggested that addition of chain extender increased the molecular weight and broader molecular weight distribution of recycled poly (ethylene terephthalate). A gel fraction of cross-linked material was formed and the amount of gel content was dependent on the amount of chain extender used. Moreover it was found that the addition of chain extender increased the shear and elongational viscosities of recycled poly(ethylene terephthalate). The increases of viscosities were explained that the extension of poly (ethylene terephthalate) chains caused a reduction in chain mobility. As for the tensile properties at the molten and solidified state it was seen that the increase of tensile properties resulting from chain extender rose up to 0.6 wt% before it reduced at the chain extender loading of 0.9 wt%.

This research studied the flow of fluid through a rectangular barrier with the Lattice Boltzmann Method. The concept of this method relies on the streaming and collision of particles with respect to the conservation laws of mass and momentum. The objective of this research was studied patterns of fluid flow through the obstruction and Reynolds number to affect the flow pattern. The simulation showed that the flow pattern changes from laminar flow to turbulent flow when Reynolds numbers increased. In accordance with the theory.