Preparation And Properties Of Modified Basalt Fiber/Natural Rubber Composites

As a new type of green environmental protection material Basalt fiber?abbreviated as BF?not only has good mechanical properties,high temperature resistance,excellent stability,good chemical resistance,easy processing,non-toxic,environmental protection and cheap,but also has a good Low rolling loss.The use of basalt fiber in natural rubber can effectively reduce the loss factor of the composites but due to the hydrophilic and oleophobic characteristics of the basalt fiber surface,the bonding force with the matrix is weak and easy to agglomerate in the rubber.In order to reduce the loss factor while improving the mechanical properties of the composites,the basalt fiber needs to be modified.In the study of the surface modification and application of basalt fiber,the most common study is the modification by coupling agent,which can improve the dispersion of the filler in the matrix,prevent aggregation,and enhance its interfacial adhesion with the matrix.The titanate coupling agent can modify the surface of the inorganic material to improve the dispersibility and the filling amount of the filler.In addition,the physical and physicochemical properties of the filler and the fiber surface can be further improved by introducing foreign fillers such as nanoparticles,and the performance of the composites can be improved by adding nanoparticles.In this paper,acetic acid pretreatment,titanate coupling agent TG-38S,titanate coupling agent and nano-Al₂O₃ were jointly used to modified basalt fiber.The surface form and elemental composition of basalt fiber were analyzed by electron microscopy,infrared spectroscopy and energy spectrum.The modified basalt fiber were used to prepare modified basalt fiber/natural rubber composites.The tensile,tearing,and dynamic mechanical properties of basalt fiber with different length-diameter ratios and different amounts in composites were tested.The change of the loss factor tan?of the composite material was analyzed.The results show that the acetic acid pretreatment improves the mechanical properties of the basalt fiber composites.Among them,the tensile strength of the3mm sample increases by 6.7%,the elongation at break increases by 3.1%,the tearing strength increases by 9.3%.,and the hardness increased by 9.5%.At the same time,the tan?decreased.With a frequency of 1 Hz and a strain of 7%,the tan?of the 3 mm sample decreased of 12.3%from 0.057 to 0.050 at 60°C.With the increase of the length of basalt fiber,the tensile strength and elongation at break showed the first decrease and then increase,and showed an optimal value at 3mm.The tan?of the composites first rised and then fell.When the basalt fiber length is 3 mm,the tan?is the smallest.With the increase of the amount of pre-treated basalt fiber,the mechanical properties of composites decreased slightly,and tan?first decreased and then increased.When the dosage was 6 parts,the natural rubber composite had the smallest tan?.When frequency was 1Hz,and strain was 7%,the tan?at 60°C was0.051,which was 15%lower than the 0.060 when it was not added.Using 5%titanate coupling agent modified 3mm acetic acid pretreated basalt fiber,the tensile strength of the composite material showed the best value,increased by 8.3%;the elongation at break increased by 2.2%.The tear strength of the sample with 3%titanate coupling agent showed an optimal value,which was increased by 18.8%and the Shore A hardness was increased by 2.9%.With the increase of the amount of titanate coupling agent,the tan?of the composites first decreased and then increased.When the amount was 3%,the tan?of the natural rubber composite was the smallest.When frequency was 1Hz,and strain was 7%,the tan?at 60°C decreased from 0.051 to 0.023,a decrease of 54.9%.With the increase of the amount of nano-Al₂O₃,the Shore A hardness of the rubber composites showed an upward trend;the tensile strength and the elongation at break all showed an increase and then decrease,and reached a maximum at 15%;the right-angled tear strength performance an upward trend.When the amount of nano-Al₂O₃ is 15%,the tan?of the composite is the smallest.When frequency was 1Hz,and strain was 7%,the tan?at 60°C was 0.026,which was 28%lower than the 0.036 when it was not added.The use of nano-alumina and titanate coupling agent modified basalt fiber can effectively reduce the rolling resistance of composite materials.