甲基丙烯酸缩水甘油酯接枝低密度聚乙烯沥青改性剂改性机理研究

分别用低密度聚乙烯(LDPE)以及甲基丙烯酸缩水甘油酯接枝低密度聚乙烯(GMA-g-LDPE)对中海36-1基质沥青进行改性,研究了软化点、低温延度以及高温储存稳定性随着改性剂含量变化而变化的规律.通过动态剪切流变试验(DSR)和弯曲梁流变试验(BBR)测试表明,GMA-g-LDPE改性中海36-1基质沥青的高温、低温性能分别优于LDPE改性中海36-1基质沥青.通过荧光光学显微镜观察发现,两种改性沥青的相态区别较大.两种改性沥青与基质沥青的FTIR比较显示,不同吸收峰有一定的变化, GMA-g-LDPE改性中海36-1基质沥青的FTIR验证了GMA-g-LDPE中的环氧基团与沥青体系中官能基团发生了反应.研究推断,GMA-g-LDPE与中海36-1基质沥青之间形成的网络结构导致了GMA-g-LDPE改性中海36-1基质沥青的性能优于LDPE改性中海36-1沥青.     

GMA-g-LDPE与胜华沥青相容性的研究

利用LDPE和甲基丙烯酸缩水甘油酯接枝的LDPE两种材料对胜华牌沥青改性。研究了LDPE和GMA—g—LDPE与胜华牌基质沥青之间的相容性。通过高温稳定测试得知，LDPE在改性沥青中高温稳定性较差，而GMA—g—LDPE在改性沥青中高温稳定性较好。荧光光学显微镜观察发现两种改性沥青的相态区别较大，GMA—g—LDPE改性沥青体系中聚合物颗粒I大小差异小并且均匀的分布在沥青体系中，而LDPE改性沥青的聚合物颗粒大小差异较大，两相界面明显。离析后的显微研究表明，GMA接枝LDPE沥青之间形成的网络结构改善了GMA—g—LDPE与沥青相容的均匀性。     

红外光谱法分析SBS改性沥青的影响因素探讨

准确地测定改性沥青中SBS的掺量对工程中控制改性沥青的质量至关重要。选取六种不同的基质沥青、五种不同的SBS改性剂制备改性沥青,然后对其进行红外光谱测试及分析。通过对基质沥青、SBS以及改性沥青红外光谱图的吸收峰分析可以得出,基质沥青的种类、SBS的种类不同均不会对改性沥青吸收峰出现的位置造成影响。同时分析结果表明,基质沥青种类、SBS种类均不会对965cm~(-1)处的吸收峰峰高造成影响,而SBS的掺量对改性沥青965 cm~(-1)处的吸收峰的峰高具有显著的影响。根据改性沥青红外光谱中965cm~(-1)处的吸收峰峰高及其峰高的影响因素分析,说明红外光谱法检测改性沥青中SBS掺量是可行的。     

红外光谱仪在SBS改性沥青质量控制中的应用

依托某高速公路项目在现场改性沥青质量控制过程中,采用德国BRUKER红外光谱仪对基质沥青、改性沥青进行光谱分析,根据基质沥青、不同改性剂掺量的改性沥青的波数965 cm~(-1)和1 377 cm~(-1)特征吸收峰的吸光度关系,建立SBS改性剂含量与特征吸收峰处吸光度的线性回归模型,以此来定量分析SBS改性剂沥青中改性剂掺量的稳定性,为改性沥青质量控制提供参考。     

红外光谱法测定改性沥青中SBS含量的研究

利用红外光谱分析技术,对基质沥青、SBS和SBS改性沥青进行定性和定量分析。结果表明:SBS改性沥青的红外光谱中,在1 377 cm~(-1)和810 cm~(-1)处的吸收峰是基质沥青的特征峰;在966 cm~(-1)和699 cm~(-1)处的吸收峰是SBS的特征峰;SBS特征吸收峰与基质沥青特征吸收峰的强度比与SBS含量具有良好的线性关系;采用在1 377 cm~(-1)处吸收峰作为内部参照峰的定量分析方法,得到的线性相关系数优于采用810 cm~(-1)处吸收峰作为内部参照峰的定量分析方法;A (966)/A(1 377)和S(966+699)/S (1 377)与SBS含量具有良好的线性关系,相关系数R~2大于0.998,相对误差小于5%,可以实现对SBS含量的准确测定。     

制备储存稳定的LDPE/SBS共混物改性沥青

比较了直接添加LDPE、SBS改性沥青与LDPE／SBS熔融共混物改性沥青的高温储存稳定性，并利用光学显微镜观察了各种改性沥青在高温下随时间的变化，结果表明：直接添加LDPE，SBS所得到的改性沥青，其高温储存稳定性很差，在反应剂加入后得到了一定程度的改善，而采用预先制备LDPE／SBS共混物，再将其添加到沥青中，在反应剂存在的条件下，所得到的改性沥青能够在高温下稳定储存，同时，相形态观察也表明，直接添加改性沥青，无论加入反应剂与否，都存在聚合物颗粒聚集现象，而共混物改性沥青的高温相形态则不随时间变化，这一点与稳定性测试结果相吻合。     

环氧化SBS的制备及其对沥青的改性

对SBS进行环氧化改性，通过红外光谱证实了SBS的环氧化反应产物中环氧基团的存在。SBS环氧化反应适宜条件为：反应温度70℃、反应时间3h、SBS溶液浓度100g／L、甲酸与过氧化氢体积比为1：2.5。所得产物的环氧基质量百分数为12．7％。环氧化SBS改性沥青的针入度、软化点和延度与基质沥青比较都有变化，其中延度变化最显著。     

PE改性沥青性能研究

在阐述改性机理的基础上，对两种基质沥青及四种改性剂量的低密聚乙烯(LDP)E改性沥青进行了常规的试验研究，深入分析了改性前后沥青各技术指标的变化原因，指出了LDPE对于基质沥青高低温性能，耐老化性能等方面的作用。     

改性沥青中SBS含量检测技术应用研究

对基质沥青和SBS进行了红外光谱测试,结果表明SBS改性沥青红外光谱中964cm~(-1)处SBS基团特征吸收峰可作为SBS定性和定量分析依据。在改性沥青中SBS含量测试准确性、稳定性分析的基础上,结合实体工程,开展红外光谱法精确测量改性沥青SBS含量案例分析。     

基质沥青与 SBS 改性沥青的老化性能分析

以辽河AH90沥青为基质沥青,在其中加入质量分数为3%的苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)改性剂,可制备改性沥青。利用沥青软化点随时间的变化关系,建立了2种沥青的老化动力学模型:lnR基=3.784 1.33×103texp(-4946/T),lnR改=3.949 1.54×103texp(-5 242/T)。通过比较2种沥青的动力学参数,得出改性沥青的抗老化性能优于基质沥青。借助红外光谱分析可知,基质沥青的老化主要是吸氧氧化反应;而改性沥青的老化除了具有基质沥青的老化反应外,还存在SBS中聚丁二烯链段的断裂和氧化反应。     

环氧大豆油改性氧化沥青研究

选用环氧大豆油改善氧化沥青物理与力学性能，使改性沥青的软化点下降，延度与针入度显著升高，其综合性能基本接近优质道路沥青的指标。扫描电镜与红外光谱分析结果表明：环氧大豆油中环氧基与沥青质、树脂质中的羟基、酚基之间发生物理化学作用，显著提高了环氧大豆油与沥青之间相容性，使沥青质更均匀地分散在改性沥青中，从而改善了氧化沥青的性能。     

Study and Evaluation of Aging Performance of Petroleum Asphalts and Their Constituents During Oxygen Absorption. III. Average Molecular Structure Parameter Changes

The changes of the structural parameters of the average molecules of Chinese Shanjiasi and Shengli petroleum asphalts and their constituents during oxygen absorption were studied based on the oxygen absorption behaviors and the chemical group composition and structure changes. The results show that all the structural parameters of the average molecules of asphalts and their constituents increase clearly after oxygen absorption with the exceptions of the naphthene carbon rates and the paraffin carbon rates. The parameters include the total carbon numbers, the aromatic carbon numbers, the naphthene carbon numbers, the paraffin carbon numbers, the total ring numbers, the aromatic ring numbers, the naphthene ring numbers, the total hydrogen numbers, the aromaticities, and the concentration indexes. The most obvious are the structural parameter changes of the average molecules of the asphalt resin and asphaltene constituents. The structural parameter changes of the average molecules of Shengli asphalt and its constituents are remarkably greater than those of Shanjiasi asphalt and its constituents. The clearer changes of all the average molecular structure parameters of SHL asphalt resin and asphaltene, especially resin could possibly be one of the key factors leading to the much clearer deterioration of the colloidal stability and the serviceability than SJS asphalt in oxygen absorption.     

运用DMA方法研究基质沥青组成对SBS改性沥青黏弹性能的影响

选取4种组成不同的基质沥青制备SBS改性沥青,运用动态力学分析（DMA）方法分析改性沥青黏弹性能。结果表明,采用温度扫描、频率扫描和稳态流动试验得到的改性沥青高温性能具有一致性,基质沥青中芳香分含量是影响改性沥青黏弹性能的主要因素,芳香分含量越高,制备的改性沥青高温黏弹性能越好,饱和分含量过高,会减弱改性沥青内聚力,降低高温黏性。低温弯曲梁流变试验结果表明,胶质和沥青质主要影响改性沥青低温性能,基质沥青沥青质含量过高,改性沥青低温延伸性能越差。     

Study and Evaluation of Aging Performance of Petroleum Asphalts and Their Constituents During Oxygen Absorption. III. Average Molecular Structure Parameter Changes

Abstract

The changes of the structural parameters of the average molecules of Chinese Shanjiasi and Shengli petroleum asphalts and their constituents during oxygen absorption were studied based on the oxygen absorption behaviors and the chemical group composition and structure changes. The results show that all the structural parameters of the average molecules of asphalts and their constituents increase clearly after oxygen absorption with the exceptions of the naphthene carbon rates and the paraffin carbon rates. The parameters include the total carbon numbers, the aromatic carbon numbers, the naphthene carbon numbers, the paraffin carbon numbers, the total ring numbers, the aromatic ring numbers, the naphthene ring numbers, the total hydrogen numbers, the aromaticities, and the concentration indexes. The most obvious are the structural parameter changes of the average molecules of the asphalt resin and asphaltene constituents. The structural parameter changes of the average molecules of Shengli asphalt and its constituents are remarkably greater than those of Shanjiasi asphalt and its constituents. The clearer changes of all the average molecular structure parameters of SHL asphalt resin and asphaltene, especially resin could possibly be one of the key factors leading to the much clearer deterioration of the colloidal stability and the serviceability than SJS asphalt in oxygen absorption.     

高黏度改性沥青黏韧性的影响因素

沥青黏韧性试验是评价沥青改性效果的一种典型试验,评价高黏度改性沥青时常存在拉脱的现象,未必能够反映高黏度改性沥青的特性.研究了SBS含量、25℃针入度和基质沥青组分对高黏度改性沥青黏韧性的影响.结果表明,黏韧性随着SBS含量的增加先增大后减小;针入度小的改性沥青的黏韧性试验荷载大,最大变形小;针入度大的改性沥青荷载小,...     

RELATIONSHIPS BETWEEN ASPHALTENES,HEITHAUS COMPATIBILITY PARAMETERS,AND ASPHALT VISCOSITY

ABSTRACT

Historically, asphalt rheology has been described in terms of a colloidal model, which depicts asphalts as dispersions of asphaltenes in petrolenes (maltenes). The model leads to a classification of asphalts into sol, gel, or intermediate categories. Sol and gel type asphalts exhibit differences in physical and chemical behavior. Sol asphalts also are described as compatible, while gel asphalts are described as non-compatible. The relative viscosity of an asphalt, defined as the quotient of the viscosity of the whole asphalt divided by the viscosity of the n-heptane soluble maltene fraction at a given temperature and rate of shear is one measure of asphalt compatibility. Based on this definition of compatibility, asphalts with low values of relative viscosity are designated as compatible and higher values of relative viscosity are designated as incompatible. Asphalt compatibility is also related to the asphaltene content, where asphalts with low asphaltene content are designated as compatible. It is claimed that the Heithaus parameters also are measures of asphalt compatibility. Therefore there should be a relationship between relative viscosities (π_rel), Heithaus parameters, and n-heptane asphaltene volume fractions ( φn-heptane)- Such a relationship has been derived assuming that the Heithaus p_a parameter is numerically equivalent to α in the Pal-Rhodes equation.     

STUDIES ON NIGERIAN CRUDES 3. ANALYSIS OF SULFURIZED ASPHALTS

The residual asphalts obtained from three Nigerian medium crudes were chemically treated with elemental sulfur at 210 to 250°C. The course of the reaction was followed by monitoring the growth of the asphaltene content of the products. The sulfurization reaction led to 5- to 10-fold increases in the asphaltene content of the products. The asphaltene content of one of the samples initially increased with temperature from 210 to 240°C and then dropped sharply. The results obtained revealed that the optimum temperature of the sulfurization reaction was 240°C. It was also observed that the lower the asphaltene content of the untreated asphalt, the higher the growth of the asphaltene content of the product at the same reaction temperature. The absolute viscosity of the sulfurized asphalts increased rapidly with increasing temperature of reaction.     

STUDIES ON NIGERIAN CRUDES 3. ANALYSIS OF SULFURIZED ASPHALTS

ABSTRACT

The residual asphalts obtained from three Nigerian medium crudes were chemically treated with elemental sulfur at 210 to 250°C. The course of the reaction was followed by monitoring the growth of the asphaltene content of the products. The sulfurization reaction led to 5- to 10-fold increases in the asphaltene content of the products. The asphaltene content of one of the samples initially increased with temperature from 210 to 240°C and then dropped sharply. The results obtained revealed that the optimum temperature of the sulfurization reaction was 240°C. It was also observed that the lower the asphaltene content of the untreated asphalt, the higher the growth of the asphaltene content of the product at the same reaction temperature. The absolute viscosity of the sulfurized asphalts increased rapidly with increasing temperature of reaction.