橡胶粉的溶解度对改性沥青性质的影响

研究了橡胶粉溶解度对橡胶粉改性沥青的动态剪切流变性质和低温蠕变性质的影响。研究结果表明，随着溶解度的增加，改性沥青60℃和135℃的粘度降低，58℃复合模量降低，相角增加，低温蠕变劲度和蠕变劲度斜率随溶解度的增加变化不大。与基质沥青相比，橡胶粉的加入改善了沥青的抗车辙能力，弹性响应加强，低温性质得到较大程度的改善。     

橡胶粉的溶解度对改性沥青性质的影响

通过橡胶粉溶解度对橡胶粉改性沥青的传统指标性质研究，得出，随着溶解度的增加，60℃软化点降低和针入度增加，15℃延度降低；但用延展性评价橡胶粉改性沥青的延展性具有一定的局限性；溶解度增加有利于沥青与橡胶粉之间的相容性，但橡胶粉改性沥青体系的稳定性则与橡胶粉改性沥青的改性机理密切相关。     

橡胶粉的溶解度对改性沥青高温性质和储藏稳定性的影响

通过不同条件下橡胶粉的溶解度对改性沥青软化点、60℃粘度以及在储藏后离析容器上部与底部的软化点差和粘度差影响,研究了橡胶粉的溶解度对改性沥青高温性质以及储藏稳定性的影响,研究发现随着溶解度的增加,改性沥青的软化点降低,60℃旋转粘度降低、改性沥青的离析软化点差先增加后降低,60℃粘度比先增加后降低。     

高浓度聚合物体系稳定性及驱油效果评价

高浓度聚合物驱油技术是一种新型的大幅度提高原油采收率的方法,但是高浓度聚合物体系的黏度稳定性及体系的驱油效果是目前矿场需要了解的问题。在室内试验的基础上,进行了高浓度聚合物体系黏度稳定性评价,并对体系的浓度和相对分子质量对驱油效果的影响进行研究。试验表明:时间对体系黏度有一定影响,而且随着体系浓度的增加,时间对体系黏度的影响逐渐减小;在剪切速率和剪切时间分别一定的条件下,体系的降解率随着相对分子质量的增加而降低,随体系浓度的增加而增加,但是高浓度体系的保留黏度大;聚合物浓度越高、相对分子质量越高,驱油效果越好。     

聚丙烯酰胺溶液粘度的影响因素

考察了温度、聚丙烯酰胺(PAM)含量及亚铁离子对聚丙烯酰胺溶液粘度的影响。结果表明,随着温度升高,聚丙烯酰胺水溶液剪切粘度随之下降,剪切粘度对数与温度的倒数符合线性关系;随 PAM 含量的增加,PAM 溶液剪切粘度随之增加;PAM 溶液中加入10mg·L~(-1)亚铁离子,会引起 PAM 大分子降解,相对分子质量降到原来的1/7,导致 PAM 溶液剪切粘度大幅度下降。     

可生物降解脂肪-芳香族共聚酯的材料性能研究

采用稀土-钛催化剂,以1,4-丁二醇、己二酸和对苯二甲酸二甲酯为原料制备了含己二酸丁二醇酯(BA)和对苯二甲酸丁二醇酯(BT)单元的系列共聚酯(BA-co-BT)。采用GPC、DSC、流变仪等方法表征了BA-co-BT的相对分子质量、力学性能、热性能和流变性能。表征结果显示,对于含40%～60%(x)BT的BA-co-BT,在相对分子质量及其分布相近时,随BT含量的增加,BA-co-BT的热性能和韧性得到改善,玻璃化转变温度和熔点升高。BA-co-BT熔体的表观黏度随剪切速率的增加而降低,属剪切变稀的假塑性流体,且在低剪切速率下熔体表观黏度对温度更敏感。通过堆肥降解实验研究了BA-co-BT的生物降解性能。实验结果表明,含40%(x)BT的BA-co-BT具有良好的生物降解性。     

乳化沥青黏度的影响因素

乳化沥青的黏度反映其内在本质,也与测定条件有关。研究简述了沥青体积分数、平均颗粒直径与分布、界面膜与增稠剂、剪切速率以及温度等因素对乳化沥青黏度的影响。颗粒直径呈单峰分布的乳化沥青,黏度随沥青的体积分数增加而增大,在体积分数相同时,颗粒直径较小的乳化沥青黏度较大。界面的流变性影响乳化沥青的黏度,界面黏度大则乳化沥青的黏度大。加入增稠剂使体系黏度增大,升高温度使乳化沥青的黏度减小。低浓度乳化沥青表现为牛顿流体性质,颗粒直径单峰分布的较高浓度乳化沥青为非牛顿型流体,黏度与剪切速率相关。     

Sasobit~改性沥青黏温影响因素研究

在0.002 5~250 s~(-1)剪切速率范围内,分析了掺加及未参加Sasobit~沥青的稳态剪切黏度对剪切速率的依赖性。掺加Sasobit~后,在64℃下PG64—22沥青变为剪切变稀型流体。剪切速率依赖性随着Sasobit~掺量的增加而增加。在100℃下观察到了Sasobit~相似的效果:随着Sasobit~的掺加,水平及剪切速率依赖性降低,在124℃时几乎可以忽略不计。同时,黏度变化率在较高剪切速率下较高,在较低剪切速率下较低。对PG76-22M沥青,在所有3个温度下,随着Sasobit~掺量增加,剪切速率依赖性增加。这表明,如果现场实际的剪切速率高于黏度测量所使用的剪切速率,目前正使用的拌和及压实温度可能较低。     

橡胶沥青的工艺优化

通过设计正交试验和应用极差分析法,以克拉玛依石化公司沥青为原料,内掺橡胶粉及改性助剂,采用剪切-反应法制备橡胶沥青,考察了废胶粉加入量、反应温度和反应时间对沥青性能的影响,确定最优条件为:胶粉加入量21%,反应温度180℃和反应时间3h。在最优条件下制备的橡胶沥青各项指标均符合交通部橡胶沥青技术标准的要求,其软化点和5℃延度均达到最高值,离析满足SBS改性沥青的离析指标,表现出良好高低温性能和储存稳定性。     

苯乙烯焦油对橡胶改性沥青性能的影响

实验以辽河油田生产的沥青为原料,加入橡胶粉和苯乙烯焦油,以高速剪切法制备改性沥青。考察了橡胶粉和苯乙烯焦油对沥青性能的影响,并对改性沥青进行老化实验。确定最佳橡胶粉质量分为15%,并向质量分数为15%橡胶改性沥青中加入苯乙烯焦油,使橡胶粉可在沥青中充分溶胀,提高橡胶沥青的使用性能。实验表明,苯乙烯焦油的加入可提高橡胶改性沥青的性能,此时沥青的软化点可达39.7℃,沥青的针入度可以达11(0.1mm),延度为121cm,符合140号道路沥青标准。老化实验表明,改性沥青老化后橡胶粉有聚结和析出。     

微波对胶粉与沥青交互作用的影响

制备了不同微波时间处理的胶粉改性沥青,用凝胶渗透色谱测定了微波处理胶粉的甲苯抽出物的相对分子质量分布,采用溶剂抽提法将胶粉改性沥青的胶粉相与沥青相分离,用热重分析考察胶粉的交联度和橡胶烃含量的变化。结果表明,胶粉改性沥青的性质与其甲苯中的溶解度有明显的联系;经过5 min微波处理的胶粉,在沥青中的降解程度最高,胶粉在沥青中破碎形成带状结构,其制备的改性沥青的延度和针入度最高,软化点稍低;微波处理时间为5 min时胶粉中的部分大分子发生解交联,产生中等大小的分子,而继续延长微波处理时间到6 min,使5 min时形成的中等分子又重新与大分子反应连接。沥青中胶粉的交联度随微波时间延长先减小后增加,4 min时达到最大,而橡胶烃含量随微波时间延长先减小后增加,5 min时达到最小。胶粉交联度的减小有利于沥青中轻组分溶胀进入胶粉内部,使沥青中重组分相对含量提高,沥青变硬。而胶粉中降解产生的小分子,进入沥青后,使沥青变软,并且在胶粉和沥青之间形成界面层增强了二者的作用力。     

INVESTIGATION OF THE CURING VARIABLES OF ASPHALT-RUBBER BINDER

A curing study was undertaken to determine the effect of asphalt type, rubber content, rubber mesh size, rubber source, curing time, curing temperature, and rate of mixing on the properties of asphalt-rubber binder. Properties studied were asphalt composition, rubber dissolution, molecular weight distribution, and the low, intermediate, and high-temperature rheological properties. These properties were found to be dependent on the above listed variables. Most notable were the curing variables of curing time, curing temperature, and rate of mixing. Increasing the curing time, curing temperature, and rate of mixing increased the amount of rubber dissolution into the asphalt during the curing process. Increased rubber dissolution was determined to improve the low- and intermediate-temperature rheological properties of a binder. Furthermore, after the initial increase in high-temperature viscosity with the addition of rubber, the high-temperature viscosity decreased significantly with increased rubber dissolution     

INVESTIGATION OF THE CURING VARIABLES OF ASPHALT-RUBBER BINDER

ABSTRACT

A curing study was undertaken to determine the effect of asphalt type, rubber content, rubber mesh size, rubber source, curing time, curing temperature, and rate of mixing on the properties of asphalt-rubber binder. Properties studied were asphalt composition, rubber dissolution, molecular weight distribution, and the low, intermediate, and high-temperature rheological properties. These properties were found to be dependent on the above listed variables. Most notable were the curing variables of curing time, curing temperature, and rate of mixing. Increasing the curing time, curing temperature, and rate of mixing increased the amount of rubber dissolution into the asphalt during the curing process. Increased rubber dissolution was determined to improve the low- and intermediate-temperature rheological properties of a binder. Furthermore, after the initial increase in high-temperature viscosity with the addition of rubber, the high-temperature viscosity decreased significantly with increased rubber dissolution     

废胎胶粉改性沥青影响因素探讨

采用斜交胎和子午胎两种废胎胶粉对基质沥青(中海70号沥青和SK70号沥青)进行改性,试验研究结果表明:胶粉掺量为20%,搅拌温度为180℃,废胎胶粉为斜交胎时,改性沥青的高温稳定性、低温抗裂性、弹性恢复性能较基质沥青有明显提高;胶粉粒径可根据技术经济性选择合适的粒径等级;斜交胎胶粉的改性沥青性能明显好于子午胎胶粉;从高温性能、感温性能及弹性性能指标来看,中海70号改性效果比SK70号沥青差,但其低温指标略好。     

天然橡胶在芳烃油中溶胀和溶解过程的考察

Aromatic oil has been used to promote the properties of crumb rubber modified asphalt which is an ideal method to deal with the resource utilization of waste tire rubber and by-product of refinery. Furfural extract oil (FEO) was separated into light fraction and heavy fraction. Swelling and dissolution process of nature rubber sheet in these three oils was investigated to deal with the interaction mechanism. Crumb rubber was also interacted with FEO and asphalt respectively. Energy dispersive spectrometer (EDS), thermo-gravimetric analysis (TGA) and scanning electron microscope (SEM) were used to characterize the chemical and structural properties of processed rubber. Chemical composition of processed oils and asphalt was investigated by using four groups analysis (SARA) and gel permeation chromatography. The results reveal that swelling rate and mass loss of rubber in oils were much higher than those in asphalt and rose with increasing process temperature. Heavy fraction of FEO had more diffusion and dissolving capacity than light fraction, whilst compatibility was observed between heavy fraction with light fraction. Selectivity absorption was not observed in the study and detachment of dissolved rubber happened from outside to inside. The cross-linking degree of the residue rubber kept unchanged with process time, and sulfur preferred to remain in the undissolved rubber. Dissolution of crumb rubber in oils was attributed to devulcanization, and that in asphalt mainly belonged to depolymerization.     

发育时间对橡胶沥青性能的影响研究

制备了不同发育时间的胶粉改性沥青样品,并通过动态剪切流变仪（DSR）和弯曲梁流变仪（BBR）等对其进行分析。用得到的高温指标（黏度、软化点、车辙因子等）和低温指标（延度、蠕变劲度）分析发育时间对胶粉改性沥青性能的影响。结果表明：胶粉改性沥青样品的高温性能和低温性能均较好;但随发育时间的增加,高温性能和低温性能有所下降,温度敏感性变大,胶粉和沥青的相容性变好,热储存稳定性变好。     

微波胶粉比表面积对橡胶沥青流变性能的影响

通过考察不同微波辐射时间对胶粉活化处理并制备胶粉改性沥青的效果,研究微波辐射对胶粉表观特性与其改性沥青流变性能的影响。采用气体吸附仪、动态剪切流变仪分别测定胶粉活化前后的比表面积及改性沥青的流变性能,并将胶粉的比表面积与沥青流变性能进行关联。在此基础上,结合扫描电镜,从微观角度揭示活化胶粉对沥青流变性能的影响机理。结果表明:在测定时间内,微波辐射使得胶粉表面变得蓬松,孔隙增多,比表面积增长显著;一定时间范围内(60～120s)的微波辐射对胶粉改性沥青的高温抗车辙能力有显著影响;胶粉微波活化后其比表面积与改性沥青流变性能之间有很好的相关性,胶粉比表面积越大,其复数剪切模量越大,相位角越小,沥青的高温抗变形能力越好。     

Study on the Technological Conditions of Crumb Tire Rubber-Modified Bitumens

Abstract

The use of waste tire rubbers as bitumen modifiers can contribute to alleviating pollution problems caused by discarding scrap tires. This article deals with the preparation and influencing factors of bitumens modified by crumb tire rubber. The performance of crumb tire rubber—modified bitumens (CTRMBs), such as penetration grade, softening point, and ductility, have been studied as a function of rubber selection, shearing temperature, shearing rotational speed, shearing time, rubber addition, and blended oil addition. From the experimental results obtained, optimal technology conditions were determined as: a shearing time of 40 min, a shearing temperature of 180°C, a shearing rotational speed of 7000 rpm, a rubber addition less than 25 wt%, and a blended oil addition less than 4 wt% during manufacturing operations. By using blended oil, the modified asphalt that measured up to standard of the crumb rubber—modified asphalt (FHWA-SA-92-002) was prepared, following the process flow diagram.     

Investigation of Swelling and Dissolution Process of Natural Rubber in Aromatic Oil

Aromatic oil has been used to promote the properties of crumb rubber modified asphalt which is an ideal method to deal with the resource utilization of waste rubber tires and by-product of refinery. Furfural extract oil(FEO) was separated into the light fraction and the heavy fraction. Swelling and dissolution process of natural rubber sheet in these three oil samples was investigated to shed light on the interaction mechanism. Crumb rubber also interacted on FEO and asphalt respectively. Energy dispersive spectrometer(EDS), thermo-gravimetric analysis(TGA) and scanning electron microscope(SEM) were used to characterize the chemical and structural properties of processed rubber. The chemical composition of processed oils and asphalt was investigated by using the hydrocarbon group analysis(SARA) and gel permeation chromatography. The results revealed that the swelling rate and mass loss of rubber in oils were much higher than those in asphalt and rose with an increasing processing temperature. The heavy fraction of FEO had more diffusion and dissolving capability than the light fraction, whilst compatibility was observed between the heavy fraction and the light fraction. Selective absorption was not observed in the study and detachment of dissolved rubber was disseminated from the outside to the inside. The cross-linking degree of the residue rubber was unchanged with the processing time, and sulfur predominantly remained in the undissolved rubber. Dissolution of crumbed rubber in oils was attributed to devulcanization, while that in the asphalt was mainly attributed to depolymerization.     

速溶胶粉改性沥青混合料的研究

橡胶胶粉的三维化学交联结构使其难以在沥青混合料中分散,限制了其在道路中的应用。采用预先高效解交联方法制备了速溶胶粉,并通过干法和湿法工艺制备了速溶胶粉改性沥青混合料。对比分析了速溶胶粉和原胶粉改性沥青混合料的体积指标、抗飞散能力和马歇尔稳定度等性能。通过观察胶浆的微观结构,比较了不同胶粉的分散情况。进一步探究了油石比对速溶胶粉改性沥青混合料性能的影响。结果表明,与原胶粉相比,速溶胶粉在沥青混合料中分散地更细(微米尺度)、更均匀,速溶胶粉改性沥青混合料更易压实、粘结性能更佳。采用速溶胶粉取代原胶粉可以降低胶粉改性沥青的加工温度,干法时结合焖料工艺也可进一步降低沥青用量,部分替代沥青。