Self-reinforced composite materials based on ultra-high molecular weight polyethylene fibers | Mekhanika | kompozitsionnykh | materialov i konstruktsii

Self-reinforced composite materials based on ultra-high molecular weight polyethylene fibers

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Abstract:

In this paper a method for the production of self-reinforced composite materials based on ultrahigh molecular weight polyethylene (UHMWPE) was proposed. Self-reinforced composite materials are materials in which both reinforcing phase and polymer matrix are represented by a material of the same nature. The obtaining of bulk samples of self-reinforced composite materials was carried out by the compression molding of UHMWPE fibers. The choice of UHMWPE fibers for the obtaining of self-reinforced composite materials was caused by the fact that these fibers have the best values of specific tensile strength among all materials that has found real practical application. Compression molding in the temperature range close to the melting point of the fibers made it possible to control the melting of the fiber surface. Upon cooling the molten part solidified and formed a matrix of the composite material. Since at high temperatures there will be a loss of the oriented state of UHMWPE fibers, which is accompanied by a significant decrease in the elastic-strength properties of the fibers, a selection of compression molding conditions was performed, which allowed to retain the high mechanical properties of the initial UHMWPE fibers. Compression molding was carried out under high pressures, which made it possible to shift the melting temperature of the fibers toward higher temperatures, besides, to prevent shrinkage of the fibers, accompanied by loss of the oriented state. To evaluate the preservation or loss of the oriented fiber structure, an approach based on a change in the degree of crystallinity of the resulting materials was used. It was found that by varying the temperature and pressure of compression molding it is possible to change the ratio of the matrix phase to the oriented phase, which leads to a change in the mechanical properties of the resulting composite materials.

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