Study On Polypropylene/Nylon66 Or Poly (butyleneterephthalate) In-situ Composites

HDPE/PA66 and HDPE/PBT in-situ composites have been prepared by extrusion-tensile-injection method. Effects of composition, compatibilizer and draw ratio on morphology and property of composites were studied. Fibrilizated mechanics of dispersed phase and the function of fibrillar reinforceing and rigidized matrix were further examined.In-situ compositing bars have been prepared through dispersed phase fiberillered at extrusion-melt drawn moment and microfiber and matrix composited at injection phase. The number of PA66 fibers in the HDPE/PA66 composites is increased with dispersed phase contents(Cm) changed from 0 to 25%. Cross dimension and cross dimension distribution of PA66 fibers are decreased with Cm, then increased at Cm =15%. Tensile strength( t) and tensile modulus(E)of HDPE/PA66 in-situ composites are as large 45% and 40% as pure HDPE's at Cm =15%. Morphology and mechanical properties of added gPE's HDPE/PA66 in-situ composites (PA66/gPE=5/l) have changed with Cm. These changes include: the number of PA66 fibers increased, the fiber's cross dimension and the fiber cross dimension distribution having little change, the number of particle not transited into fiber and the ratio of particle to fiber number increased, the o t and E of compatibilized is-situ composites being as large 50% and 25% as pure HDPE's respectively at Cm =15%. Morphology and mechanical properties of HDPE/PBT in-situ composites have changed with Cm. These changes include: the number of fiber increased, the fiber crossdimension and the fiber cross dimension distribution decreased, the t and E of in-situ composites being 33% and 66% larger than pure HDPE's respectively at Cm =25%. Morphology and mechanical properties of HDPE/PA66(85/15w/w) in-situ composites have changed with draw ratio( ). These changes include: the number of fibers increased, the fiber cross dimension and the fiber cross dimension distribution decreased, the t and E of composites increased.The relationship between t and Cm or is thought as the result of competition and compensation between dispersed phase reinforced matrix action and interface flaw action between two phase . The dispersed phase reinforced matrix action is controlled by dispersed phase morphology. The relationship between E and Cm or is thought as the result of the dispersed phase rigidized matrix action which depended on the dispersed phase morphology.