The air permeability of composite fiber material

The air permeability of composite materials obtained by impregnating a non-woven needle-punched cloth with latex was investigated. The permeability of composite materials with different rubber content was estimated by the coefficient of air permeability at a pressure drop of 49 and 100 Pa. The dependence of the air permeability coefficient on the degree of impregnation of the fabric showed that at 15 – 20 % of the rubber content, the maximum air permeability coefficient is observed, and when the degree of impregnation increases, the air permeability coefficient decreases. The process of forming a porous structure of composite materials and its influence on air transport is considered. The increase of the coefficient of permeability is explained by the fixation of the fibers of the surface layer with limited mobility under the action of air flow, and a reduction in the coefficient of air permeability by reducing pore space and an increase in fiber matrix composite materials in the process of sushi-Ki-impregnated material. The air permeability of composite materials is determined by the ratio between the processes of increasing the volume of the fibrous matrix and reducing porosity when filling the space between the portages with rubber particles. A model is proposed for calculating the coefficient of breathability of composite materials of known density.

Effective concrete types with carbon fiber

The research was conducted in order to determine the effect of the polymer additive on the adhesion between the fiber and the cement-sand matrix, since the involvement stage of the composite fiber material directly depends on the adhesion value between these dissimilar components. Throughout the study, the issue at stake was to determine the optimal method for adhesion increasing to assess its effectiveness, and also to carry out an experiment and obtain actual numerical change values of the adhesion to carbon fiber (the assessment was made considering changes of the strength parameters). According to the results of conducted testings, the tensile strength during the bend almost wasn’t affected in resin-injected samples with the amount of fiber of 1 and 3% (increments of 12.7 and 15.7%, respectively). Despite this, the combined application of a resin with the same amount of fiber gave the increments of 34 and 20%, respectively. Conclusions are drawn about the prospects of polymer additives usage in carbon fiber reinforced concrete. The mechanism of increasing the carbon fiber involvement in the composite behavior is considered, the positive effect is confirmed by the study of the chemical processes that arise during the interaction of fiber and water-soluble resin.

Near-infrared-responsive gold nanorod/liquid crystalline elastomer composites prepared by sequential thiol-click chemistry

A novel NIR-responsive GNR/LCE composite fiber material with a very low Au loading-level (0.09 wt%) is prepared by a three-step sequential thiol-click chemistry approach.