The influence of coupling agents on the melt rheological properties of natural fiber composites has been investigated in this work using capillary and rotational rheometers. Scanning electron microscopy was also employed to supplement the rheological data. It was found that molecular weight and molecular weight distribution of the polymer matrix and coupling agent characteristics influence the filler wetting and the melt flow properties of the filled composites. Generally, low molecular weight and narrow molecular weight distribution polyethylene matrix provides relatively larger increase of the viscosity of the composites. Coupling agents tend to increase the resistance to shearing, but wall slip effects may interfere with the measured values, especially at very high filler loadings. Entrance pressure loss in capillaries is also influenced by polymer matrix and coupling agent used.
Experimental work to determine the contact rigidity of thick copper-bearing coatings formed by electrospark erosion has been carried out. It is established that the investigated coatings are porous and their density can be increased by plastic deformation without destroying the surface layer. The dependences of the decrease of the thickness of the electrospark coating (densification) on the loading force and the rigidity of the coating were obtained by the calculation-experiment method. 相似文献
