热塑性弹性体SBS的接枝改性研究

<正>1引言由于SBS化学组成及其结构的待点,将它作为粘合剂,比一般合成橡胶粘合剂更具独特之处.然而由于SBS大分子内缺少极性基团,使得SBS粘合剂与聚氯乙烯、聚氨酯和金属等材料的粘接效果不够理想,为改善其粘接性,国内外学者对其进行了接枝改性的研究.     

接枝改性SBS对PS/SBS/CaCO_3复合材料形态和力学性能的影响

采用马来酸酐(MAH)和苯乙烯(St)作为接枝单体,通过溶液聚合法合成接枝极性基团的苯乙烯-丁二烯-苯乙烯三嵌段共聚物(SBS),然后与聚苯乙烯(PS)基体、碳酸钙(CaCO_3)粒子复合,用傅立叶红外光谱仪表征接枝处理前后SBS表面化学结构的变化;并研究了SBS改性对复合材料微观结构和力学性能的影响.结果表明:双单体溶液聚合法成功地将极性基团接枝在SBS链上;填充SBS-g-MAH后,促进CaCO_3在PS基体中的分散、改善PS-CaCO_3粒子间界面粘接,起到良好的增容作用;SBS-g-MAH和CaCO_3粒子对PS基体具有协同增强增韧作用,同时能提高复合材料的拉伸强度和冲击强度.     

MAH溶液法接枝SBS的研究

采用马来酸酐（MAH）作为接枝单体,对苯乙烯—丁二烯—苯乙烯三嵌段共聚物（SBS）进行溶液接枝。研究了反应温度、反应时间、马来酸酐用量、引发剂种类及用量对接枝率的影响。得到最佳反应条件为：m（SBS）/m（MAH）/m（BPO）/m（溶剂）=100：10：0.8：400,反应温度75℃。反应时间3 h;红外光谱图证实了接枝物的生成。     

嵌段共聚物SBS／SIS的接枝改性研究

以SBS和SIS为基材,采用不同橡胶胶种、丙烯酸及其酯类单体进行接枝共聚合成胶粘剂。研究了 CSM(氯磺化聚乙烯)、A-90(氯丁橡胶)、NR(丁腈)等橡胶胶种对SBS／SIS与AA／BA／MMA／GDMA进行化学改性的影响,同时还探讨了N-MAM(N-羟甲基丙烯酰胺)、GDMA(二甲基丙烯酸乙二醇酯)、TMPTMA(三羟甲基丙烷甲基丙烯酸酯)、MAH(顺丁烯二酸酐)、VAc(醋酸乙烯)等单体对SBS／SIS、丁腈橡胶、氯丁橡胶为接枝母体进行化学改性的效果。结果表明:以SBS／SIS为基材,以氯丁橡胶(A-90)为接枝母体,用AA／BA／ MMA／环氧丙烯酸酯／MAH／N-MAM／GDMA／TMPTMA／VAc混合单体进行接枝改性制得的胶粘剂对极性材料帆布的粘附力较强;以SBS／SIS为复合基材,以丁腈橡胶为接枝母体,用AA／BA／MMA／TMPTMA混合单体接枝改性制得的胶粘剂对非极性材料PP片的粘接强度较高。     

SBS／MMA／BA／MAA四元接枝共聚及其产物粘接性能

研究了SBS与甲基丙烯酸（MAA）和甲基丙烯酸甲酯（MMA）,丙烯酸丁酯（BA）的四元接枝共聚,探讨了MMA／BA质量比,MMA与BPO用量,反应时间,反应温度及固化时间对粘接性能的影响,并将该四元接枝胶的性能与三元胶和SBS／MMA／BA／AA四元胶进行了比较,结果发现：该四元胶对聚烯烃的粘接强度及室温固化性能优于SBS／MMA／BA三元胶,尤其与异氰酸酯配合使用时,其效果更佳,而且该四元胶的粘接强度,耐水及耐热性能均优于SBS／MMA／BA／AA四元胶。     

MAH改性SBS的性能研究

研究了马来酸酐（MAH）接枝改性苯乙烯／丁二烯／苯乙烯共聚物（SBS）的方法及其性能。用红外光谱分析确定了MAH已接枝到SBS上,用DSC分析了接枝物的纯度。MAH改性的SBS溶于三元体系溶剂,可制得价廉的胶粘剂,粘接强度高于不用MAH改性的SBS。     

MMA、BA与SBS接枝共聚及其粘接行为的研究

本文对BA、MMA与SBS接枝共聚及其产物的粘接行为进行了研究,探讨了单体浓度、引发剂浓度、反应温度和反应时间对接枝聚合的影响。用PGC、IR对经提纯过的PBA-g-SBS-g-PMMA进行了分析表征。通过性能测试证实:该胶粘剂初粘力强、终粘强度高、毒性小、熔融温度低,使用时勿需添加低分子增粘剂。     

LM-S沥青改性剂提高沥青混合料黏附性能的分子模拟计算及路用性能考察

沥青与石料的黏附性大小直接影响沥青混合料的强度、稳定性、耐久性等性质。通过分子模拟计算的方法研究沥青与石料的黏附作用,计算比较沥青改性前后与石料间的黏附功,并与水煮法沥青黏附性实验结果及沥青混合料微观形貌研究结果进行比对;同时考察沥青改性剂LM-S对沥青混合料路用性能的改进效果。结果表明,采用LM-S改性后的沥青-石料体系的界面黏附功比基质沥青-石料体系提高了近26%,因而具有更好的黏附性;沥青混合料实验结果亦表明LM-S改性剂可显著提高基质沥青和SBS改性沥青混合料的高温稳定性能、低温稳定性能及水稳定性性能,其中动稳定度分别提高了162%和43%。     

Effect of material composition on antistripping performance of SBS modified asphalt mixture under dry and wet conditions

Styrene-butadiene-styrene (SBS) modified asphalt used in road engineering is a complicated mixture of various compositions. The present study was undertaken to evaluate the influence of different raw materials and their content on the moisture stability of SBS copolymer modified asphalt mixture. A total of 18 different combinations of base asphalt, SBS, furfural extract oil (FEO), and stabilizer were considered to prepare different SBS modified asphalt samples, and the contact angle test was carried out to determine the work of adhesion and the work of debonding of SBS modified asphalt with aggregate. Moreover, a multi-factor Analysis of Variance (ANOVA) was conducted to investigate the statistical effects of the material composition factors. The results show that the bond strength between SBS modified asphalt and aggregate is significantly affected by the source of base asphalt, but it is insensitive to the change of SBS type under dry and wet conditions. Besides, the moisture damage resistance of SBS modified asphalt improves firstly and then reduces with the rising storage of SBS, FEO, and stabilizer. Furthermore, linear regression analysis suggests that the work of adhesion under dry condition has excellent correlation with the work of debonding under wet condition.     

Preparation and properties of bitumen modified with the maleic anhydride grafted styrene‐butadiene‐styrene triblock copolymer

A procedure to improve the properties of styrene‐butadiene‐styrene (SBS) copolymer modified bitumen by grafting of maleic anhydride (MAH) onto SBS in the presence of benzoyl peroxide (BPO) as initiator was proposed. The effects of the grafting degree (GD) on the properties of modified bitumen were investigated. FTIR spectroscopy was employed to verify the grafting of MAH onto SBS. The GD of MAH onto SBS was determined by a back titration procedure. To assess the effects of the GD of grafted SBS on properties of modified bitumen, the softening point, penetration, ductility, elastic recovery, penetration index, viscosity, storage stability, and dynamic shear properties were tested. Experimental results indicated that the SBS grafted with maleic anhydride (SBS‐g‐MAH) copolymer was successfully synthesized by solvothermal method, and different GD of the SBS‐g‐MAH was obtained by control the MAH concentration. The GD of the MAH onto SBS has great effect on the rheological properties of the modified bitumen, and the high temperature performance and storage stability of modified bitumen were improved with the GD of the MAH onto SBS increasing. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers