| As a large-scale,continuous transportation machinery,conveyor belts have been widely used in coal mines,metallurgy,chemical industry,transportation and other fields.Its structure is mainly composed of covering glue,glue core layer and skeleton material.When the conveyor belt is used in special working conditions,due to the irregular shape,heavy weight and sharp surface of the minerals,the covering rubber layer on the surface of the conveyor belt will cause serious damage and wear during transportation,resulting in damage to the conveyor belt.and shortened service life.Therefore,this paper aims to develop a high-strength and high-wear-resistant conveyor belt covering material for special working conditionsIn this paper,using NBR as the matrix and PU as the reinforcing material,the effects of processing parameters,synthesis and use of NBR/PU system compatibilizers on the properties of NBR/PU composites were studied.Conveyor belt products were prepared with the developed covering material,and the possibility of its application in special working conditions was evaluated.The details are as follows:(1)NBR/PU composites with different NBR:PU ratios were prepared,and the effects of PU content,carbon black content,and vulcanization temperature on the properties of composites were studied,and the optimal process conditions were obtained.The results show that within the experimental range,the tensile strength of NBR/PU composites is mainly affected by the amount of PU and the amount of carbon black.Influence of PU dosage and carbon black dosage,with the increase of PU dosage,the wear first decreased and then increased,and with the increase of carbon black dosage,the wear decreased first and then increased;with the increase of PU dosage and carbon black dosage,the composite The Payne effect of the material is obviously enhanced,and the dispersion of the filler in the rubber becomes worse;and according to the SEM image and the tan?-temperature curve,it can be seen that with the increase of the amount of PU,the compatibility of the composite material becomes worse.According to the data analysis,the comprehensive selection process conditions are:PU dosage of 50 parts,carbon black dosage of 40 parts,and vulcanization temperature of 150?.Under these conditions,the tensile strength of NBR/PU composite is 21.167 MPa and DIN wear is 158 mm3.(2)Two series of compatibilizers,HTBN-PU and HTBN-4CPI,were prepared by reacting hydroxyl-terminated liquid nitrile rubber(HTBN)with diphenylmethane diisocyanate(MDI)and p-chlorophenyl isocyanate(4CPI),respectively.Effects of NBR/PU composites on properties.The results showed that the mechanical properties,wear resistance and storage modulus of the composites were improved after adding the compatibilizer.With the increase of compatibilizer content,the tensile strength and storage modulus showed a trend of increasing first and then decreasing,and the abrasion showed a trend of decreasing first and then increasing.According to the RPA data and the tan?-temperature curve,after adding the compatibilizer,the dispersion of the filler becomes better and the two Tg of the composite material are close to each other,indicating that the compatibility between the composite materials has been improved.Among the four compatibilizers HTBN-4CPI has the best improvement effect on the composite material.When adding 0.98%HTBN-4CPI,the tensile strength was 28.648 MPa,which increased by 35%.DIN wear was 70 mm3,56%reduction.(3)NBR/PU composite material modified by compatibilizer was used as conveyor belt covering adhesive and wire rope core was used as skeleton material to prefabricate conveyor belt products.The results show that the tensile strength of conveyor belt products is 1355.8kN/m,and the adhesive property of wire rope is 116.7N/mm,which meet the performance requirements of conveyor belt products.The conveyor belt with high strength and high wear resistance is successfully prepared.The conveyor belt can be used in coal mine and other special conditions. |
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