Applied Theory

• lIU Xu, LIANG Lin, LIU Yilin, DING Naixiu, ZHANG Baogang
• Effect of Coupling Agents on Magnetic Properties of Magnetic NBR

• 2024 Vol. 71(4): 0250-0255

  [Abstract](46)

  [PDF](37)

• Abstract:In this paper，two kinds of silane coupling agents and four kinds of titanate coupling agents were used to prepare magnetic nitrile rubber（NBR），and the influence of coupling agents on the magnetic properties of magnetic NBR was investigated.The results showed that the magnetic properties of the compounds with titanate coupling agents were better than those with silane coupling agents，among which the magnetic properties of the compound added with titanate coupling agent A13 were the best.With the increase of the dosage of coupling agent A13，remanence（B_r），intrinsic coercivity（H_CJ） and maximum magnetic energy product （BH）_max increased first and then decreased，while coercivity（H_CB） had no obvious change pattern.When the dosage of coupling agent A13 was 1% of the dosage of magnetic powder，the compound had the optimal magnetic properties：B_r 0.224 T，H_CB 165 kA·m^-1，H_CJJ 279 kA·m^-1，（BH）_max 9.7 kJ·m^-3.

• YU Benhui, SHAN Tilun, WANG Kongshuo, WANG Jing, REN Jianbin, LI Shaoming, WANG Chuansheng
• Effect of Short Fiber on Properties of EPDM Composites

• 2024 Vol. 71(4): 0256-0265

  [Abstract](38)

  [PDF](345)

• Abstract:The effects of different types of short fiber（length） on the properties of ethylene-propylene-diene rubber（EPDM） composites were investigated.The results showed that，the composite using aramid short fiber （refered to as AF）（9 mm）/basalt short fiber （refered to as BSF）（9 mm） with a blending ratio of 1/1 had a smaller Mooney viscosity，the lowest DIN wear（113.51 mm³），and the best ablation resistance.The basic properties and thermal stability of the composite with precipitated silica were comparable to those of the composite with gas-phase silica.The greater the length of BSF was，the better the wear resistance and ablation resistance of the composite were.As the length of BSF increased，the Payne effect of the composite decreased.Compared with the BSF（3 mm） composite，the BSF（9 mm） composite had the smallest Payne effect，and the dispersibility of BSF（9 mm） was best .In TG analysis，at 700 ℃，the quality retention rate of the composite in descending order was the BSF（9 mm）/AF（9 mm） blend composite，BSF（3 mm） composite，AF（9 mm） composite，AF（6 mm） composite，AF（3 mm） composite.

Material · Compounding

• WANG Qian, ZHANG Junchi, LYU Guijie, XUE Xinyuan, SUN Tao, LIU Heng, ZHANG Chunyu, SUN Yu, ZHANG Xuequan
• Application of Liquid 1，4-polybutadiene in SBR Compounds

• 2024 Vol. 71(4): 0266-0270

  [Abstract](44)

  [PDF](41)

• Abstract:The application of liquid 1，4-polybutadiene（LPB） in styrene butadiene rubber（SBR） compounds was studied.The results showed that the microstructure of LPB mainly consisted of cis-1，4-structure and trans-1，4-structure.Using LPB as a plasticizer to replace environmentally friendly aromatic oil（TDAE），the t₁₀ and t₉₀ of the compound were extended，the wear resistance of the vulcanizate increased，and the rolling resistance decreased，but at the same time，the wet slip resistance was reduced.Replacing TDAE with an equal amount of LPB resulted in a decrease in the tensile properties of the vulcanizate, while partially replacing TDAE with LPB resulted in an improvement in the tensile properties of the vulcanizate.

• WANG Han, DONG Yongxiu, CAO Youhua, XIAO Jianbin
• Effect of Compatibilizers on Properties of MPU/NBR Blends

• 2024 Vol. 71(4): 0271-0276

  [Abstract](38)

  [PDF](33)

• Abstract:Acrylate rubber（ACM） and ethylene acrylate rubber（AEM） were used as compatibilizers，and their effects on the properties of mixed polyurethane rubber（MPU）/nitrile rubber（NBR） blends were studied.The results showed that adding compatibilizers ACM and AEM to MPU/NBR blends could promote the co-vulcanization of MPU and NBR，make the vulcanization characteristics between the two more compatible，and improve the compatibilities，physical properties，heat resistance and thermal oxygen aging properties of the blends.The compatibilizer AEM improved the performance of the blend better than the compatibilizer ACM.When the dosage of compatibilizer AEM was 20 phr，the two phases of the blend were completely compatible.

• FANG Haobin, DU Jie, ZHENG Hongbing, LUAN Bo, XIONG Zihan, CHEN Wenlin, HE Yingping
• Improving Properties of Natural Rubber Latex Film Reinforced with Silica

• 2024 Vol. 71(4): 0277-0280

  [Abstract](37)

  [PDF](40)

• Abstract:Silica was used to reinforce the natural rubber latex film，and the effects of the dosages of sulfur，accelerator PX，zinc carbonate and silica on physical properties of the vulcanized rubber film were studied by orthogonal test.The results showed that，taking the tensile strength of the vulcanized rubber film as the index，the influences of the four factors in descending order were accelerator PX，silica，zinc carbonate and sulfur.the optimal dosages were 0.9 phr of accelerator PX，1.11 phr of silica，0.6 phr of zinc carbonate and 1 phr of sulfur，and the tensile strength of the corresponding formulated vulcanized rubber film reached 31.37 MPa.Taking the tear strength of the vulcanized rubber film as the index，the influences of the four factors in descending order were silica，accelerator PX，sulfur and zinc carbonate，the optimal dosages were 1.31 phr of silica，0.7 phr of accelerator PX，1.25 phr of sulfur and 0.5 phr of zinc carbonate，and the tear strength of the corresponding formulated vulcanized rubber film reached 65 kN·m^-1.

Product · Design

• XIAO Mingqing, WANG Kejin, Cui Haocheng, YANG Haibo
• Design and Optimization of Compound for Outer Part of Stop-grouting Plug

• 2024 Vol. 71(4): 0281-0286

  [Abstract](36)

  [PDF](40)

• Abstract:A new type of stop-grouting plug with sealing and exhausting functions was designed，and numerical simulation analysis of the actual working state of the stop-grouting plug was carried out using the finite element method to optimize the compound of the outer part of the stop-grouting plug.The results showed that as the hardness of the compound for the outer part of the stop-grouting plug decreased，the sealing performance of the stop-grouting plug was improved.Taking into account both sealing performance and cost，it was determined that the outer part of the stop-grouting plug was made of NR compound with a Shore A hardness of 40 degrees.

Technology · Equipment

• XU Yudong, MU Bingzhen, LIU Mengqi, CHEN Hailong
• Influence of Thermal Conductivities and Interlayer Contact Thermal Resistances of Carbon Filler/NR Composites on Microwave Heating Effect

• 2024 Vol. 71(4): 0287-0292

  [Abstract](37)

  [PDF](35)

• Abstract:Carbon black/natural rubber（NR），graphene/NR and carbon nanotubes/NR composites were prepared，and the effects of the thermal conductivities and interlayer contact resistances of the composites on microwave heating were studied by combining experimental and numerical simulation methods.The results show that the higher the thermal conductivities of carbon black，graphene and carbon nanotubes were，the higher the thermal conductivities of the composites were，and the lower the interlayer contact thermal resistances were.Increasing the filler amounts to increase the thermal conductivities of the composites and reduce the interlayer contact thermal resistances had certain limitations，and the applicability and economy of the composite formulation design needed to be considered.The thermal conductivities of the composites had little effect on the distribution patterns of high and low temperature regions and microwave heating efficiencies during the microwave heating process，however，the temperature distribution uniformities of the composites were significantly affected by the thermal conductivities.In order to ensure the uniformity of microwave heating vulcanization，the interlayer contact thermal resistances of multilayer composites could not be ignored.

• XIE Jiacheng, YANG Haiwei
• Research on 3D Printing Process for Sleeve and Extension Sheath Small Assembly

• 2024 Vol. 71(4): 0293-0298

  [Abstract](39)

  [PDF](32)

• Abstract:Power tools usually come with sleeves and extensions.To avoid direct contact between workers and rotating sleeves and extensions during fastening operations，a thermoplastic polyurethane（TPU） sleeve and extension sheath small assembly was designed to be both safe and easy to install.For the sleeve and extension sheath small assembly，SolidWorks and Teamcenter softwares were used for 3D modeling and virtual assessment of the vehicle environment.TPU samples were trial-produced using 3D printing technology，and through the orthogonal experimental method，the influence of printing process parameters on the hardness and tensile properties of the samples was analyzed，and an ideal combination of 3D printing process parameters of the sleeve and extension sheath small assembly was obtained：printing layer height　0.2 mm，wall thickness　1.2 mm，printing temperature　220 ℃，and printing speed　35 mm·s^-1.The sleeve and extension sheath small assembly printed under this process condition met the usage requirements.

Testing · Analysis

• BI Yanliang, JIANG Xiaotian, WANG Linhua
• Compression Test and Analysis of Solid Sealing Frame for Rail Vehicle Air Conditioner

• 2024 Vol. 71(4): 0299-0304

  [Abstract](35)

  [PDF](36)

• Abstract:The compression test and analysis were conducted on the solid sealing frame（referred to as the sealing frame，using EPDM as the main material） of rail vehicle air conditioner.The results showed that if the compression rate of the sealing frame exceeded 50%，irreversible deformation would occur.In actual use，it was necessary to control the compression ratio of the sealing frame to avoid damage of the sealing frame caused by excessive compression.Under 25% compression rate，the compression force of the sealing frame was approximately linearly related to the centerline total length.By using the compression force calculation formula at any size and compression amount（compression ratio less than 30%），the theoretical calculation of the compression force of the sealing frame could be carried out in advance，effectively avoiding the problem of unqualified air conditioning installation.

• YIN Hanjian, LIU Benxin
• Simulation Study on Effect of Drum Size on Durability of Off-The-Road Radial Tire

• 2024 Vol. 71(4): 0305-0311

  [Abstract](37)

  [PDF](35)

• Abstract:Taking the 445/95R25 all-steel off-the-road radial tire as an example，the three-dimensional model of off-the-road radial tire was established，Yeoh model was determined as the optimal rubber material constitutive model through fitting rubber material stress and strain test data，and the simulation research on the impact of the drum size on the tire durability was conducted.The results showed that，under the same inflation pressure and load，as the drum diameter increased，the tire deflection decreased，the contact area with the drum increased，and the circumferential contact pressure distribution became more uniform，leading to the decrease in the extreme values of the tire shoulder strain energy density，Mises stress and shear strain.When the drum diameter exceeded 10 m，the effects of the drum diameter on the contact characteristics between the tire and drum and the tire’s mechanical properties were significantly reduced.When the drum diameter increased from 1.7 m to 3 m，the tire shoulder strain energy density decreased by 5%，and the tested tire durability life was extended by about 20%.

Comprehensive and Special Review

• CHEN Baiyu, GUAN Denggao, PENG Yan, LIU Tao
• Research Progress in Shear Thickening Fluids and Their Composites

• 2024 Vol. 71(4): 0312-0319

  [Abstract](36)

  [PDF](30)

• Abstract:Shear thickening fluid（STF），as a new generation of intelligent energy consuming materials，was widely used in fields such as puncture resistance，impact resistance and vibration damping.In this paper，the characteristics and shear thickening mechanism of STF were introduced，and the preparation methods，including impregnation or spraying，interlayer or filling，blending and encapsulation of STF composites were reviewed.The puncture resistance，impact resistance and vibration damping of STF composites and their application were analyzed.It was recommended to further explore the shear thickening mechanism of STF and develop STF composites that are environmentally insensitive，have a long service life，can be applied at high impact rates，and exhibit magnetorheological or electrorheological properties.

Special Contribution

• YAN Lizhi, XIAO Yao, TANG Shaoshu, LIANG Jinzhou, XU Zhenchun, WANG Chuansheng, BIAN Huiguang
• Preparation and Properties of Hollow Glass Microsphere/NR Low Thermal Conductivity Composites

• 2024 Vol. 71(4): 0243-0249

  [Abstract](38)

  [PDF](38)

• Abstract:The preparation and properties of hollow glass microsphere（HGM）/natural rubber（NR） low thermal conductivity composites（referred to as compounds） were introduced.The results showed that replacing silica with an appropriate amount of HGM effectively reduced the storage modulus and Mooney viscosity of the compound，and improved the processing properties of the compound，but it was not conducive to the physical properties of the compound.Reducing the amount of HGM could improve the tensile strength，elongation at break and tear strength of the compound，but it could reduce the wear resistance of the compound.Replacing silica with an appropriate amount of HGM was beneficial for the lightweighting of the compound and improving the heat insulation properties of the compound，and effectively reduced the rolling resistance of the compound.