酵母菌生物脱硫胎面胶粉及其填充天然橡胶的力学性能

用酵母菌对胎面胶粉(GTR)进行了生物脱硫实验,考察了酵母菌与GTR共培养脱硫过程中酵母菌的生长情况,对比了GTR和脱硫GTR(DGTR)填充天然橡胶(NR)硫化胶的交联密度、表面元素含量和力学性能.结果表明,在共培养脱硫过程中酵母菌依然可以保持较高的生物量,脱硫6 d后可获得生物脱硫的GTR.随着胶粉用量的增加,填充NR硫化胶的交联密度和力学性能逐渐降低.相比较GTR/NR硫化胶,DGTR/NR硫化胶的表面硫元素含量和交联密度更低,力学性能明显提高.     

间歇搅拌工艺对鞘氨醇单胞菌废胎面胶粉脱硫的影响

采用间歇搅拌工艺研究鞘氨醇单胞菌（PL 1）与废胎面胶粉（GTR）共培养脱硫,考察了PL 1对GTR的脱硫效果及脱硫胶粉（DGTR）填充丁苯橡胶的力学性能。结果表明,在GTR脱硫温度为30℃、在PL 1菌液中培养10 d的条件下,与连续搅拌工艺相比,采用间歇搅拌工艺,PL 1生长旺盛,其在DGTR胶片表面的附着量大;采用搅拌12 h、停歇12 h的间歇搅拌工艺,DGTR表面含硫质量分数比GTR下降了22.7%,脱硫效果显著;与GTR相比,用DGTR填充丁苯橡胶的力学性能显著改善。     

废胎面胶粉的生物脱硫与化学脱硫效果对比

分别用酵母茵和Delink脱硫剂对废胎面胶粉(GTR)进行生物脱硫和化学脱硫,研究了酵母茵的生长情况,考察了脱硫胶粉对其填充丁苯橡胶(SBR)硫化胶交联密度、物理机械性能和动态力学性能的影响,并对填充硫化胶的相态结构进行了表征.结果表明,加入GTR后,酵母菌的生物量略有下降,但经过4 d后仍能维持较高的生物量水平;生物...     

酚硫化物/醇复合促进剂对废轮胎胶应力诱导脱硫反应的影响

在废轮胎胶(GTR)与三元乙丙橡胶(EPDM)熔融挤出过程中添加多烷基苯酚二硫化物(简称420)或/和仲丁醇作为脱硫促进剂,考察了在不同螺杆转速和挤出反应温度下脱硫促进剂对GTR与EPDM脱硫共混物(DGTR/EPDM)凝胶含量和溶胶分子链结构的影响,研究了DGTR/EPDM/丁苯橡胶(SBR)再硫化胶的相态结构及物理...     

亚临界流体挤出法复合诱导丁苯橡胶基轮胎胶粉脱硫及再硫化材料的性能研究

将丁苯橡胶（SBR）基轮胎胶粉（GTR）与三元乙丙橡胶（EPDM）混合物在双螺杆挤出机中熔融挤出,通过亚临界流体与高剪切应力相结合复合诱导SBR基GTR脱硫,研究亚临界流体品种、螺杆转速、促进剂450以及挤出反应温度对脱硫共混物［脱硫GTR（DGTR）/EPDM］凝胶质量分数、门尼粘度、溶胶红外光谱以及SBR/DGTR/EPDM再硫化材料拉伸性能和断面形貌的影响。结果表明：亚临界水、乙醇和丙醇均能很好地促进脱硫反应,提高交联键断裂的选择性,降低DGTR/EPDM的凝胶质量分数和凝胶颗粒尺寸,明显提高SBR/DGTR/EPDM再硫化材料的拉伸性能,其中亚临界乙醇的作用最显著;添加促进剂450能促进脱硫反应;200 ℃时亚临界丙醇脱硫效果较佳。     

单螺杆挤出机连续脱硫制备再生胶的结构与性能

利用本课题组研制的单螺杆挤出机,对废旧轮胎胶(GTR)粉进行连续脱硫制备再生胶(DGTR),并对DGTR进行再硫化制成DGTR硫化试样.结果显示,随螺杆转速增加,DGTR凝胶含量和DGTR硫化试样交联密度逐渐降低,DGTR硫化试样的拉伸强度和拉断伸长率有所提高;螺杆转速设定为40 r·min^-1时,在205℃脱硫温度下取得了最好的脱硫效果,DGTR硫化试样的拉伸强度和拉断伸长率分别约为11 MPa和386%.从红外光谱和光电子能谱的分析结果推测,在单螺杆挤出机的剪切和热等的共同作用下,GTR粉中部分S-S键和C-S键发生了断裂.     

氧化亚铁硫杆菌脱硫天然橡胶粉及其填充胶的性能

从铁矿土壤中分离出1株氧化亚铁硫杆菌,比较了其在不同Fe2+质量浓度的改进9 K培养基中的生长情况,确定最佳的天然橡胶胶粉加入时间为培养开始后的第30 h。利用氧化亚铁硫杆菌在较低Fe2+质量浓度的改进9 K培养基中进行脱硫实验,脱硫橡胶表面的傅里叶变换红外光谱、X射线光电子能谱分析和培养液中SO42-的浓度变化都表明氧化亚铁硫杆菌是通过氧化硫黄的代谢途径来断裂橡胶中的硫黄交联键。用该脱硫胶粉填充天然橡胶硫化胶的力学性能有一定程度的提高;通过扫描电子显微镜可以看出脱硫胶粉与天然橡胶基质的界面结合较好,应力集中点较少,脆断面的断裂线均匀。     

废胶粉表面微生物脱硫及其改性沥青的性能研究

本研究应用微生物对废胶粉表面进行脱硫,使胶粉中的硫交联键断裂,提高胶粉表面化学活性点,从而强化胶粉与沥青的联结效果,提高胶粉在热融沥青中的稳定性,改善胶粉改性沥青的路用性能。应用自行配制的缺硫培养基,在特定条件下,能够加速氧化亚铁硫杆菌对胶粉表面脱硫,微生物活性较高,脱硫效果明显;氧化亚铁硫杆菌对废旧轮胎橡胶粉含硫量有着很好的改性效果,氧化铁硫杆菌在废轮胎胶粉中生长20天后,废胶粉中的含硫量减少7%~8%;从橡胶粉表面形态对比中,可以看出微生物对橡胶粉的表面形貌有较大的改变。综上可以说明微生物对废旧轮胎橡胶粉的表面脱硫是可行的,且具有较好的效果。未脱硫胶粉改性沥青的软化点随胶粉用量增加而增加,而脱硫胶粉对沥青改性使沥青的软化点保持相对稳定。脱硫针入度增加,储存稳定性变好。     

铁氧体辅助微波脱硫活化胶粉及其与丁苯橡胶并用胶性能的研究

以微波吸收能力强的纳米铁氧体与胶粉共混,对胶粉进行微波脱硫活化,研究胶粉/铁氧体共混物和改性胶粉/丁苯橡胶(SBR)并用胶的性能。结果表明:铁氧体可增强微波对胶粉的脱硫活化效果,随着微波辐照时间的延长,胶粉呈现脱硫活化效应增强直至碳化的过程;当微波功率为400 W时,微波辐照时间为3min左右胶粉脱硫效果较好,胶粉/铁氧体硫化胶的拉伸强度和拉断伸长率较大;微波辐照胶粉与SBR的相容性改善,随着SBR用量的增大,胶粉/SBR并用胶的拉断伸长率增大,拉伸强度呈先增大后略减小并很快保持稳定的趋势,铁氧体在胶粉/SBR并用胶中起到一定的补强作用。     

亚临界流体挤出法对天然橡胶基轮胎胶粉脱硫化反应的影响

采用亚临界流体挤出法对天然橡胶基轮胎胶粉(GTR)与三元乙丙橡胶(EPDM)进行熔融共混脱硫,得到脱硫轮胎胶粉(DGTR)/EPDM共混物,然后与丁苯橡胶(SBR)共混制备了再硫化材料,考察了亚临界流体品种和双螺杆挤出机螺杆转速、挤出温度对GTR脱硫效果与再硫化材料物理机械性能的影响,并通过傅里叶变换红外光谱和扫描电子显微镜表征了脱硫共混物和再硫化材料。结果表明,在相同挤出温度和螺杆转速条件下,采用亚临界水挤出制得的DGTR/EPDM共混物的凝胶含量和门尼黏度较采用其他亚临界流体挤出共混物低;在3种亚临界醇状态下,采用亚临界甲醇挤出DGTR/EPDM共混物的凝胶含量较低,门尼黏度最高;采用亚临界醇所得DGTR/EPDM/SBR再硫化材料的拉伸性能均明显优于采用亚临界水所得的再硫化材料,其中,采用亚临界乙醇且在挤出温度为180℃、螺杆转速为500 r/min、反应压力为2.0 MPa的条件下,所制得DGTR/EPDM/SBR再硫化材料的拉伸强度和扯断伸长率分别达到19.4 MPa和456%;采用不同亚临界流体脱硫后制得再硫化材料中未熔融凝胶粒子尺寸大小不等,其中采用亚临界水时最小,小于1μm,分别采用亚临界甲醇、乙醇时较小,约为1μm,而采用亚临界丙醇时较大;随着反应温度的升高或螺杆转速的增加,再硫化材料中凝胶粒子的数目及尺寸均明显减小。     

亚临界流体挤出法复合诱导SBR基轮胎胶脱硫化及 再硫化材料力学性能

在SBR基轮胎胶(GTR)与三元乙丙橡胶（EPDM）混合物的熔融挤出过程中,采用改变亚临界流体品种和提高螺杆转速的方法,研究了亚临界流体（水,乙醇,丙醇）、螺杆转速、烷基酚多硫化物促进剂（450）以及温度对脱硫共混物（DGTR/EPDM）凝胶含量、门尼粘度、溶胶红外光谱及脱硫共混物共混丁苯橡胶（SBR）再硫化材料（SBR/(DGTR/EPDM)）力学性能的影响,对再硫化材料的试样断面形貌也进行了SEM观察。实验结果表明：亚临界流体（水,乙醇,丙醇）作为一种溶胀剂和反应性介质能够很好地促进脱硫反应,提高交联键断裂的选择性,降低脱硫产物的凝胶含量和凝胶颗粒尺寸并明显提高脱硫共混物共混丁苯橡胶再硫化材料的力学性能,其中亚临界乙醇的作用最显著。当450作为一种脱硫促进剂,在最优亚临界乙醇挤出反应条件（200℃,1.6 MPa,600 rpm）下,脱硫共混物共混丁苯橡胶分别达到丁苯生胶混炼硫化材料拉伸强度（24.0MPa）和断裂伸长率（356%）的99.6%和209%。     

Effects of shear stress and subcritical water on devulcanization of styrene–butadiene rubber based ground tire rubber in a twin‐screw extruder

The devulcanization reaction of styrene–butadiene rubber (SBR) based ground tire rubber (GTR) in GTR/ethylene–propylene–diene monomer rubber (EPDM) blend was investigated through a compound‐induced reaction by increasing screw rotation speed and being in the presence of subcritical water. The effects of temperature, pressure, screw rotation speed, or promoting agents on the gel content, Mooney viscosity, and Fourier transform infrared spectra of the sol of the devulcanized blends (devulcanized ground tire rubber (DGTR)/EPDM) were measured, and the mechanical properties and microstructures of the revulcanized blend ((DGTR/EPDM)/SBR) were characterized. The results show that subcritical water as a swelling agent and reaction medium promotes the devulcanization reaction, increases the selectivity of the crosslink breakage, keeps the extrusion material from oxidative degradation, reduces the gel particle size of the devulcanized blends, and significantly improves the mechanical properties of the revulcanized SBR/(DGTR/EPDM) blends. In subcritical water, the suitable promoting agents (alkylphenol polysulfide 450, hydrogen peroxide H₂O₂, or 450/H₂O₂) accelerate the devulcanization reaction, keep the double bond content, and lead to further decrease of the gel content and Mooney viscosity of the devulcanized blends and further increase of the mechanical properties of the revulcanized SBR/(DGTR/EPDM) blends. Especially the compound promoting agent (450/H₂O₂) improves the selectivity of the crosslink breakage in devulcanization of SBR‐based GTR. When 450/H₂O₂ is added as a compound promoting agent at the best reaction condition in subcritical water (200°C, 1.6 MPa and 1000 rpm), the tensile strength and elongation at break of the revulcanized SBR/(DGTR/EPDM) blends reach to 85.4% and 201% of vulcanized SBR (24.0 MPa, 356%), respectively. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1845–1854, 2013     

Improvement of the properties of natural rubber/ground tire rubber composites through biological desulfurization of GTR

The surface desulfurization of ground tire rubber (GTR) had been carried out via a biological treatment by Thiobacillus sp. with strong sulfur oxidizing capacity. The bonding states and element content on the surface of GTR and desulfurated GTR (DGTR) were evaluated using an X-ray Photoelectron Spectroscopy (XPS). The contact angle of GTR was 120.5° and decreased down to 93.5° after treatment. The cure characteristics, swelling behavior, and crosslink density of natural rubber (NR)/GTR and NR/DGTR were examined. The improvement in mechanical properties was observed for NR/DGTR vulcanizates, which was attributed to the enhanced interfacial interaction between DGTR and NR matrix. The dynamic mechanical analysis (DMA) results showed that NR/DGTR vulcanizates had a reduction of molecular chain friction resistance during glass transition region and Scanning electron microscopy (SEM) studies further indicated a good coherency and homogeneity between DGTR and NR matrix.     

螺杆结构对轮胎胶粉超声波脱硫工艺及性能的影响

采用负载超声波发生装置的同向旋转双螺杆挤出机对40目废旧轮胎胶粉（GTR）进行超声波脱硫,考察了两种不同结构螺杆对脱硫过程中的口型压力和功率消耗、脱硫GTR（DGTR）的外观形貌、流变性能、硫化特性及DGTR硫化胶力学性能的影响。结果表明,在13 μm超声波振幅和含较多捏合块部件螺杆的作用下得到的DGTR的凝胶含量、黏度及储能模量较低,说明含捏合元件的螺杆剪切作用更强,能使GTR获得更高程度的脱硫。该条件下所制得的DGTR硫化胶的拉伸强度和100%定伸应力较低,扯断伸长率较高。     

不同胶粉在丁苯橡胶中的使用性能研究

系统研究了采用常温粉碎、水射流粉碎、湿法粉碎和冷冻粉碎等工艺制备的4种胶粉基本性质及其在丁苯橡胶(SBR)中的应用性能.结果表明,4种胶粉(GTR)的表面形貌和组成以及在丁苯橡胶中的使用性能均有较大差异,其中湿法胶粉比表面积较大,冷冻法胶粉表面形貌光滑.将4种胶粉分别加入到丁苯橡胶中,相应混炼胶的t90和t10均缩短;...     

废旧轮胎胶粉/聚苯乙烯共混物性能研究

研究废旧轮胎胶粉( GTR)粒径和用量以及相容剂种类和用量对GTR/聚苯乙烯(PS)共混物性能的影响.结果表明:GTR可以改善PS的脆性,提高PS的抗冲击性能,但会使拉伸性能降低;GTR粒径越小,GTR/PS共混物的抗冲击性能越好;相容剂乙烯-丙烯酸酯-甲基丙烯酸缩水甘油酯和苯乙烯-丁二烯-苯乙烯嵌段共聚物( SBS)能大幅改善GTR/PS共混物的抗冲击性能,相容剂马来酸酐接枝聚丙烯以及甲基丙烯酸甲酯、丁二烯和苯乙烯的三元共聚物对GTR/PS共混物的抗冲击性能改善不大;GTR(粒径为75 μm)/PS/相容剂SBS用量比为40/100/10时,GTR/PS共混物的综合性能较好,缺口冲击强度达到4.87 kJ·m-2.     

Characterization of recycled styrene butadiene rubber ground tire rubber: Combining X‐ray fluorescence,differential scanning calorimetry,and dynamical thermal analysis for quality control

Appraisal of the main rubber characterization techniques for styrene butadiene rubber (SBR) was performed on standard SBR samples as well as recycled ground tire rubber (GTR) from an industrial tire recycling facility, containing a blend of SBR and natural rubber. The aim of the work was to provide additional information relevant to quality control in the field of rubber recycling. Benchmark characterization of industrial samples by inductively coupled plasma optical emission spectrometry, atomic absorption spectrometry, solid‐state proton nuclear magnetic resonance, and elemental (CHNS) analysis are reported. X‐ray fluorescence spectrometry is shown to be rapid and quantitative for determining the zinc content in an industrial context. Thermogravimetric analysis, already used to determine carbon black and inorganic material content in rubbers and GTR, is recommended for determination of monomer weight ratios of SBR sources not containing other rubbers, but not for GTR. Differential scanning calorimetry (DSC) measurements of the glass‐transition show that changes in monomer ratio affect glass‐transition temperature values, and therefore, DSC can be used to detect changes in rubber composition from batch to batch. These results show that DSC and X‐ray fluorescence spectroscopy characterization techniques can be used for GTR and may lead to more thorough and rapid quality control procedures of these complex samples. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42692.     

Thermomechanical reclaiming of ground tire rubber via extrusion at low temperature: Efficiency and limits

Thermomechanical reclaiming of ground tire rubber (GTR) was performed at different temperatures (60, 120, and 180°C) using a co‐rotating twin‐screw extruder. Obtained samples were used in styrene‐butadiene rubber (SBR) blends. As reference samples, SBR compounds containing untreated GTR were used. Curing characteristics, static and dynamic mechanical properties, and morphology of the obtained blends were determined. The results show that the increase of barrel temperature during the thermomechanical reclaiming of GTR has a positive effect on the decrease of screw torque (lower machine load) and decrease of Mooney viscosity (better processing characteristics). However, mechanical properties and crosslink density of rubber revulcanizate decreased with increasing barrel temperature during the reclaiming process. SBR blends with 50 phr of reclaimed rubber showed increasing phase compatibility between SBR matrix and the reclaimed rubber, which was confirmed by mechanical properties and morphology measurements. J. VINYL ADDIT. TECHNOL., 22:213–221, 2016. © 2014 Society of Plastics Engineers