Measuring of Fiber/Matrix Adhesion in Thermoplastic Polymer Composites: A Preliminary Study

The possibilities of the application of microbond test and cylinder tests for determining the interfacial shea r strength at the fiber - matrix interface in thermoplastic matrix polymer composites were investigated . Possibilities of test specimen preparation were also investigated. Finally the applicability of the method to make high precision measurement of interfac ial shear strength was evaluated

Development of Microcapsules

Melamine-formaldehyde (PMF) coated microcapsules were produced with liquid pentaerythritol-tetrakis (3-merkaptopropionate) (PETMP) and UV-sensitive indicator colored PETMP cores. Capsules with an average diameter of 43 μm formed due to the adjustments on magnetic stirring, compound ratios, acidity and reaction time. Reproducible recipe was found to produce colored PETMP filled capsules with yields of 1-10%. Optical microscopic investigations were conducted to follow the formation of the particles, and scanning electron-microscope (SEM) was used to verify that the capsules did not break up as an effect of the brittle failure of the epoxy matrix specimens. Improvement of the shell-matrix adhesion was attempted with silane compounds and investigated with X-ray photoelectron spectroscopy (XPS) and SEM.</jats:p

POLYMER JOINTS

Parallel to the spreading of polymers as engineering materials the spreading of polymer joints can be observed. Similarly to metallic joints, according to operational principle joints working by force, by shape or by material layer can be differentiated in case of polymers, too. The aim of this paper is to review different joints emphasizing the most frequent type, the welding one. To reach a reproducible welded joint a computer controlled welding stage was built. The weldability and the joint efficiency factor were investigated at the most frequently applied polymers. It is managed to determine an optional welding speed that highly varies depending on the molecular structure of the type of polymers