Influence Of Fiber On Main Properties Of Rubber

(1) Influence of short fiber on the properties of raw rubber the existence of short fiber mainly affects the rheological properties of rubber compound, so it has a great impact on the properties of raw rubber. The addition of short fiber increased the strength, decreased the yield point and increased the hardness of raw rubber. Especially for the base rubber with relatively weak strength of raw rubber, the strength of rubber compound increases more significantly. For example, after adding 5 portions of aramid fiber to the weaker neoprene rubber, the 100% modulus of the rubber mixture is increased by 7. 8 times, and the Shore A hardness is increased by 10. Moreover, when the short fiber is embedded in the rubber, the rubber will also have obvious anisotropy, and the degree of orientation will also increase with the increase of fiber content. At the same time, the cutting resistance of the rubber material is greatly improved, which makes it difficult to cut the rubber when taking out the sheets on the open mill, especially when the fiber content is high, the machine must be stopped to cut the film.

(2) The influence of short fiber on the properties of vulcanizate In order to give full play to the reinforcing role of aramid short fiber in the elastomer, during the preparation of composite materials, it is necessary to make the short fiber have a good dispersion in the matrix, a reasonable orientation and a good adhesion between the short fiber and the matrix interface. The main factors affecting the properties of short fiber rubber composites are: the type and amount of fiber; Shape coefficient of fiber; Dispersion and orientation of fibers in the matrix; Adhesion between fiber and matrix.

(3) Adhesion between fiber and rubber The improvement of adhesion strength between fiber and rubber can greatly improve the performance of short fiber/rubber composite, increase the modulus, tensile strength and tear strength of the composite. After being mixed into the rubber matrix, the force between the untreated short fiber and the matrix is mainly as follows. One is the dispersion force between (such as glass fiber and carbon fiber) and non-polar matrix (such as natural rubber); The second is the dispersion force and induction force between polar fibers (such as vinylon, nylon, polyester, acrylic fiber, etc.) and non-polar matrix, as well as between non-polar fibers and polar matrix (neoprene, nitrile rubber, etc.); The third is electrostatic force and dispersion force between polar fiber and polar matrix. It can be seen that the force between the short fiber and the matrix is van der Waals force, and the van der Waals force is much smaller than the strong chemical bond between rubber molecules. Therefore, after the untreated short fiber is mixed with rubber, due to the small force between it and rubber molecules, it is easy to cause stress concentration when stressed, so that the mechanical properties of the composite will decline.