water absorption

New polymer composites on the basis of epoxy resin and different fine dispersed mineral powders (andesite, bentonite, diatomite, liquid glass and quartz sand) were obtained and their mechanical (ultimate strength), thermal (temperature dependence of the softening) and water absorption properties were investigated. It was established that all properties of these materials were essentially improved, when the same fillers modified by tetraetoxysilane (TEOS) were used.

PVC/wood flour composites were prepared by compression molding using sapwood and heartwood from Angelin Pedra as filler. The composites specimens were subjected to water immersion and impact tests. The results showed that the water absorption of all composites increased slightly with increasing immersion time and wood content. However, the values were considerably low compared with control sample, common solid woods and wood plastic composites reported in literature.

Possibility of fabrication by the method of extrusion of composite on the basis of polypropylene and discrete filler in the form of the grinded fabric is studied. Influence on physical-mechanical properties and water absorption of obtained materials for the fillers of various chemical nature - fabrics on the basis of synthetic or/and natural fibers, their filling degree in polypropylene, as well as dependences of these properties on pre-award dressing of filler is estimated.

Ultimate strength, softening temperature, and water absorption of the polymer composites based on epoxy resin (type ED-20) with unmodified and/or modified by tetraethoxysilane (TEOS) minerals diatomite and andesite are described. Comparison of experimental results obtained for investigated composites shows that the ones containing modified filler have better technical parameters mentioned above than composites with unmodified filler at corresponding loading.