Applied Theory

• BAI Qi, SU Youwen, LYU Xiongfei
• Study on Mechanical Properties and Freeze-thaw Resistance of Modified Rubber Concrete

• 2023 Vol. 70(2): 0091-0096

  [Abstract](118)

  [PDF](76)

• Abstract:Polypropylene fiber and fly ash were mixed with rubber concrete，and the effect of their contents on the mechanical properties and freeze-thaw resistance of rubber concrete was studied. The results showed that the compressive strength and tensile strength of the rubber concrete first increased and then decreased with the increase of polypropylene fiber content，and decreased with the increase of fly ash content. In the whole freeze-thaw cycle，the relative dynamic elastic modulus of the polypropylene fiber and fly ash filled rubber concretes decreased less than that of the unfilled rubber concrete，and the freeze-thaw damage resistance was improved. In this test，the overall performance of the rubber concrete was the best when the polypropylene fiber content was 10 kg·m^-3 and the fly ash content was 14% ～ 16%（based on the mass percentage of the substituted cement）.

• XU Tiwen, LING Feilong, SHI Bo, YU Benyi
• Study on Properties of NR/BR Blends Filled with Different Kinds of Carbon Black

• 2023 Vol. 70(2): 0097-0104

  [Abstract](117)

  [PDF](75)

• Abstract:The properties of natural rubber （NR）/butadiene rubber（BR） blends filled with five kinds of carbon black（RX2007，NC1301，NC1312，BC2109，and N234）were studied. The results showed that all five kinds of carbon black were well dispersed in the NR/BR matrix and the properties of NR/BR blend highly depended on the physical properties of the filled carbon black. It was found that the t₉₀ of the NR/BR blend filled with carbon black RX2007 was the shortest，and the t₉₀ of the NR/BR blend filled with carbon black NC1312 was the longest. The modulus，tensile strength and tear strength of the NR/BR blends filled with carbon black BC2109 and N234 were higher. The dynamic mechanical properties of the NR/BR blend filled with carbon black RX2007 were the best. The compression fatigue heat build-up resistance of the NR/BR blends filled with carbon black RX2007 and N234 was better. The wear resistance of the NR/BR blend filled with carbon black NC1312 was the best.

Material · Compounding

• ZHANG Yuxuan,HAO Dongdong and DING Yonghong
• Surface Hydrophilic Modification of Silicone Rubber and Its Properties

• 2023 Vol. 70(2): 0105-0110

  [Abstract](109)

  [PDF](89)

• Abstract:In this study，active groups were introduced onto the surface of silicone rubber by plasma treatment. Then the initiator 2-bromoisobutyryl bromide（BIBB） was grafted on the surface of the silicone rubber containing active groups through nucleophilic substitution，and polyvinylpyrrolidone（PVP） was grafted onto the silicone rubber by surface initiated atomic transfer radical polymerization（SI-ATRP）. The test results from Fourier infrared spectroscopy，X-ray photoelectron spectroscopy and field emission electron scanning microscope showed that BIBB and PVP were successfully grafted on the surface of silicone rubber. Through the water contact angle test，it was found that the water contact angle of the silicone rubber surface decreased from 110. 7^° to 36^° after PVP graft，showing improved surface hydrophilicity.

• Lianglin, ZHANG Hanzhu, ZHANG Baogang, DING Naixiu, LIU Guangye
• Effect of Type and Amount of Carbon Black on Properties of Magnetic NBR Compounds

• 2023 Vol. 70(2): 0111-0117

  [Abstract](119)

  [PDF](78)

• Abstract:The effects of the type and amount of carbon black on the properties of magnetic nitrile rubber （NBR） compounds were studied. The results showed that，with 30 phr of carbon black（N220，N330，N550， N660，N774 and N990），the magnetic NBR compound filled with carbon black N660 had the weakest Payne effect（indicating the most stable filler network structure），the magnetic NBR vulcanizate filled with carbon black N220 had the best physical properties，and the magnetic NBR vulcanizate filled with carbon black N550 had the best magnetic properties [remanence（B_r）　was 0. 220 T，coercivity（H_cb） was　165 kA·m^-1，and the maximum magnetic energy product（BH）_max　was 9. 3 kJ·m^-3]. Adding different amounts of carbon black N550 to the magnetic NBR compounds，the magnetic NBR compound filled with 20 phr of carbon black N550 had the best dimensional stability，the tensile strength of the magnetic NBR vulcanizate filled with 30 phr of carbon black N550 was the highest（9. 1 MPa），and the magnetic NBR vulcanizate filled with 10 phr of carbon black N550 had the best magnetic properties[B_r0. 228 T，H_cb　171 kA·m^-1，and（BH）_max　9. 9 kJ·m^-3].

• FENG Chang, XU Peiwen, SONG Hao, SHEN Ao, XU Ke, LEI Sheng, WANG Fajun
• Reinforcement Effect of Foundry Waste Sand Filler on NR Compound

• 2023 Vol. 70(2): 0118-0122

  [Abstract](107)

  [PDF](78)

• Abstract:The foundry waste sand was physically ground and modified with dodecyltrimethoxysilane， and then the reinforcement effect of the modified foundry waste sand as a filler on natural rubber （NR） compounds was investigated. The results showed that the modified foundry waste sand had good hydrophobicity，good dispersibility in NR and excellent compatibility with NR. The NR compounds filled with 70～80 phr of the modified foundry waste sand had high hardness，good tensile strength and tear strength， and excellent wear resistance，demonstrating preferable reinforcement capability. Therefore，the modified foundry waste sand could be used as a filler to replace part of carbon black and silica in compounds，which also generated good environmental，social and economic benefits.

Product · Design

• MA Meiqin, LIU Baoquan, YIN Ting, SHI Chengang, SUN Jianbang
• Formula Design of Internal Elastomer Compound for Flexible Joint of Marine Transportation Pipeline

• 2023 Vol. 70(2): 0123-0129

  [Abstract](90)

  [PDF](76)

• Abstract:The formula design of internal elastomer compound for the flexible joint of the marine transportation pipeline was studied. The rubber[nitrile butadiene rubber （NBR）]，reinforcing filler， plasticizer，sulfur and accelerator of the compound were analyzed through the orthogonal test，and the optimized formulation was determined as follows：the amount of NBR6240 and 6280 was 60 and 40 phr， respectively，the amount of carbon black N330 was 55 phr，the amount of carbon black N550 was 12 phr，the amount of dioctyl adipate was 7 phr，and the amount of sulfur and accelerator was 1. 8 phr（sulfur，accelerator CBS and accelerator TMTD dosages were 0. 3，1 and 0. 5 phr，respectively）. The tensile strength of the optimized NBR compound reached 22. 6 MPa，and the change rates（absolute value，same after） of the tensile strength and elongation at break after seawater aging and the change rate of the volume after oil immersion were small. The performance of the optimized compound met the performance requirements of the internal elastomer for flexible joints.

• Gao Xinwen, PEI Shipeng, ZHENG Lixia
• Effect of Nanobead Silica Amount on Properties of NR Compound for Air Spring

• 2023 Vol. 70(2): 0130-0135

  [Abstract](155)

  [PDF](86)

• Abstract:The nanobead silica was added to the natural rubber（NR） compound for the air spring，and the processing properties and physical properties of the NR compound and the fatigue resistance of the air spring were studied. The results showed that，with the increase of nanobead silica amount，the vulcanization characteristics and Mooney viscosity of the NR compound did not change significantly，the Shore A hardness of the NR vulcanizate decreased first and then increased，the tensile stress at 300% elongation did not change significantly，and the tensile strength and elongation at break both showed a decreasing trend. It was found that when the nanobead silica amount was 10～15 phr，the flexure resistance of the NR vulcanizate was better. With the addition of 10 phr nanobead silica in the NR compound for the air spring，the fatigue resistances of the air spring at room temperature and at high temperature were effectively improved.

Technology · Equipment

• GONG Yiqin,SHAN Tikun and WANG Chuansheng
• Effect of Screen Filtration of Double Drive Synchronous Gear Pump Rubber Filter on Properties of SSBR/BR Blend

• 2023 Vol. 70(2): 0136-0141

  [Abstract](82)

  [PDF](83)

• Abstract:The property change of solution polymerized styrene butadiene rubber（SSBR）/butadiene rubber（BR） blend filtered through a double drive synchronous gear pump rubber filter and the effect of the screen aperture on the properties of SBR/BR blend were studied. The results showed that，the vulcanization characteristics and physical properties of the SSBR/BR blend were improved after the screen filtration of the rubber filter. With the decrease of the screen aperture，the shore A hardness，tensile stress at 100% elongation， tensile stress at 300% elongation，tensile strength，elongation at break and tear strength of the filtered SSBR/ BR blend increased first and then decreased，and the Payne effect became weaker. When the screen aperture was 75 μm，the tensile strength and tear strength of the filtered SSBR/BR blend were the largest，which were 27. 5% and 33. 3% larger than those of the unfiltered SSBR/BR blend，respectively，the flexure resistance was best，the tanδ peak value was the largest，the glass transition temperature was the highest，the tanδ at 60 ℃ was the smallest，and the rolling resistance was the lowest.

• CAI Xiaoye, CHENG Zonghui, BAI Bing
• Lightweight Design and Manufacture of Moulds of Aerospace Rubber Bellows

• 2023 Vol. 70(2): 0142-0147

  [Abstract](82)

  [PDF](78)

• Abstract:This paper introduces the lightweight design and manufacturing of moulds of aerospace rubber bellows. In the design process，the solid structure of the upper and lower die was changed into the topological mesh lattic structure based on ensuring the same performance of the moulds，and then the STL（stereoscopic lithography ） model was generated. The lightweight moulds was manufactured by metal 3D printing and selective laser melting forming technology using CX die steel. The results of vulcanization test showed that the size of aerospace rubber bellows prepared by the lightweight moulds met the requirements of enterprise standards.

Comprehensive and Special Review

• LIU Qinyang, ZHANG Jiaxi, LIU Guoxin, ZHANG Jichuan, LIU Li
• Application Progress of Rubber Materials in Underwater Acoustic Field

• 2023 Vol. 70(2): 0148-0159

  [Abstract](107)

  [PDF](81)

• Abstract:The rubber materials had the characteristics of excellent damping performance，adjustable acoustic impedance，easy formulation adjustment and simple processing，so it had a wide range of applications in the underwater acoustic field. Based on the viscous absorption mechanism，thermal conduction absorption mechanism and molecular relaxation absorption mechanism，it was concluded that the main approaches to improve the sound-absorbing properties of the rubber materials were to design filler-filled or rubberblended sound-absorbing materials. Moreover，the research progress of the sound-transmitting and soundreflecting rubber materials was discussed based on the theoretical design and practical applications. Finally， the challenges and future development directions of underwater acoustic rubber materials were pointed out.

Special Contribution

• HUANG Ruili, GUO Bingli, LU Xun, FANG Hong
• Preparation of NR Type High Damping Elastomer Taking Advantage Tg Gradient

• 2023 Vol. 70(2): 0083-0090

  [Abstract](79)

  [PDF](77)

• Abstract:Based on the good compatibility between natural rubber（NR） and epoxidized natural rubber （ENR），and the gradient difference of glass transition temperature（T_g）of ENR with different epoxidation degrees，NR and three ENRs（ENR-25，ENR-40 and ENR-50，with a epoxidation degree of 25%，40%, and 50%，respectively） were selected to prepare a high damping quaternary blends. The damping addition effect caused by the difference of Tg and the amount of NR and ENRs on the broadening of the damping temperature range of the compound at room temperature and above was studied. The results showed that， when the blending ratio of NR/ENR-25/ENR-40/ENR-50 was 55/5/15/25 and 40 phr carbon black N330 was added，the quaternary blend had better overall performance，and its effective damping temperature range （loss factor greater than 0. 3） was 66 ℃（－15. 3～50. 7 ℃)，the tensile strength reached 17. 2 MPa，and the elongation at break was 571%.