~1H-NMR法测定苯乙烯-乙烯-丁二烯-苯乙烯嵌段共聚物的加氢度和微观结构

采用核磁共振氢谱(1H-NMR)法测定苯乙烯-乙烯-丁二烯-苯乙烯嵌段共聚物(SEBS)的加氢度和微观结构。结果表明,采用镍系催化剂对苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)进行加氢反应制备SEBS时,在苯乙烯链段未参与加氢反应的前提下,通过对SBS和SEBS的谱峰进行归属,建立了用1H-NMR测定SEBS总加氢度的方法,且无需已知苯乙烯的摩尔分数,适用范围较宽;用该法还可直接得到SEBS中各微观结构含量和丁二烯1,2-结构和1,4-结构的加氢度。     

苯乙烯-丙烯酸甲酯共聚物增容对聚乳酸/SBS共混物结晶行为的影响

研究了苯乙烯-丙烯酸甲酯无规共聚物(SMA)增容剂对聚乳酸(PLA)与苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)共混物的结晶行为的影响。通过熔融共混的方法制备了PLA/SBS (m_(PLA)∶m_(SBS)=95∶5)和PLA/SBS/SM A (m_(PLA)∶m_(SBS)∶m_(SM A)=95∶5∶3)共混物,使用扫描电子显微镜(SEM)、差示扫描量热仪(DSC)和偏光显微镜(POM)研究了SM A增容PLA/SBS共混物的形貌、非等温结晶行为、等温结晶行为和晶体形貌。结果表明,SBS的增塑效应和异相成核效应对PLA的非等温结晶和等温结晶行为有促进作用;而SMA的加入起到了降低SBS分散相尺寸的作用,同时阻碍了SBS对PLA结晶行为的促进作用。增容剂SMA阻碍SBS对PLA基体结晶行为促进作用的可能原因在于SMA在PLA和SBS界面处的阻隔作用导致两者接触面积减少,且SMA对PLA的结晶没有促进或抑制作用。     

苯乙烯-丁二烯-苯乙烯嵌段共聚物的中试连续镍系加氢反应及反应器的放大模型

采用镍系催化剂对苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)进行加氢,分析了SBS中不同微观结构的加氢反应动力学,研究了SBS中试连续加氢反应中各反应器的反应效率,提出了中试第1反应器的放大模型,并与实际值进行了比较.结果表明,乙烯基与反式-1,4-结构的反应活化能分别为20.3,24.7 kJ/mol;延长反应时间有利...     

坡缕石对苯乙烯-丁二烯-苯乙烯嵌段共聚物改性沥青性能的影响

研究了坡缕石对苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)改性沥青性能的影响.结果表明,坡缕石特殊的层链状结构和大的比表面积不仅改善了SBS改性沥青的低温性能和抗老化性能,同时形成的 .网状结构使SBS改性沥青稳定性增强.     

磨盘碾磨应力场作用下苯乙烯-丁二烯-苯乙烯嵌段共聚物的结构变化

采用原子力显微镜法、傅里叶变换红外光谱法、透射电子显微镜法、差示扫描量热法和X光电子能谱法等研究了苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)在磨盘碾磨应力场作用下．其相结构和分子结构的变化。结果表明,磨盘形力化学反应器独特的剪切和挤压力场将SBS在室温下粉碎成50～100μm的微粒;在碾磨过程中,SBS分子链断裂,特性黏数下降,聚苯乙烯分散相发生畸变,其相区尺寸增加;磨盘碾磨使SBS分子链的活性增加,诱使其发生交联反应,同时在分子链中引入含氧基团．可用于SBS的改性。     

溶胀接枝法制备具有微-纳米表面结构的苯乙烯-丁二烯-苯乙烯接枝共聚物(英文)

中对苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)与马来酸酐进行了溶胀接枝反应,当接枝率控制在11.5%时可以获得微-纳米表面粗糙结构的接枝聚合物,水在SBS接枝共聚物的表面接触角明显减小。关键词:苯乙烯-丁二烯-苯乙烯嵌段共聚物;溶胀接枝法;微-纳米表面结构;表面接触角     

炭黑对聚合物改性沥青贮存稳定性的影响

探讨炭黑添加方式和炭黑用量对聚合物改性沥青贮存稳定性的影响.结果表明,先将炭黑与苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)/低密度聚乙烯(LDPE)共混物(简称SE)混炼,再用SE/炭黑混炼胶对沥青进行改性,得到的改性沥青贮存稳定性较好;当沥青为100份时,炭黑的适宜用量为2.25份,SE(SBS/LDPE质量比为2/1)的适宜用量为4.5份.     

动态硫化乙烯-乙酸乙烯酯共聚物/苯乙烯-丁二烯-苯乙烯嵌段共聚物复合改性沥青的性能

用乙烯-乙酸乙烯酯共聚物(EVA)和苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)复合改性沥青,研究了EVA/SBS复合改性沥青动态硫化前后的软化点、针入度(25 ℃)、延度(5 ℃)及贮存稳定性,并用应变控制流变仪与光学显微镜分析了复合改性沥青的动态力学性能和相态结构.结果表明,动态硫化处理后,EVA/SBS复合改性沥青的延度和针入度下降,而软化点提高;随着硫黄用量的增加,EVA/SBS复合改性沥青的高温贮存稳定性提高,温度敏感性降低;随着EVA用量的增加,EVA/SBS复合改性沥青的高温贮存稳定性先提高后降低;当EVA质量分数为3%、硫黄质量分数为3%时,其对沥青的改性效果最佳;改性剂微粒与沥青的相容性和稳定性明显改善.     

纳米碳酸钙/苯乙烯-丁二烯-苯乙烯嵌段共聚物复合改性沥青的制备及性能

采用纳米CaCO3和苯乙烯-丁二烯-苯乙烯嵌段共聚物（SBS）作为外加剂制备纳米CaCO3/SBS复合改性沥青。通过测试基本物理性能确定了外加剂的最佳掺量,通过流变性能测试、离析试验、荧光显微镜观察及热重分析等考察了沥青的性能及微观形貌。结果表明,两种外加剂复配的最佳比例为5%（质量分数,下同）的纳米CaCO3和4%的SBS;在纳米CaCO3改性沥青中掺加SBS后,复合改性沥青在不同温度下的黏度增大,高温抗车辙能力增强,低温性能得到明显改善,储存稳定性良好;纳米CaCO3分子、SBS分子和基质沥青分子三者具有良好的相容性,经复合改性后沥青的热稳定性增强。     

苯乙烯-丁二烯-苯乙烯嵌段共聚物的加氢反应及产品性能

讨论了温度和压力在苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)加氢过程中对聚丁二烯链段中乙烯基及顺式-1,4-结构和反式-1,4-结构加氢速率的影响,比较了不同反应器对加氢反应的影响,考察了加氢前后SBS相对分子质量及其分布、动态力学性能、形态及力学性能的变化.结果表明,当反应温度为50～70 ℃和压力大于2.0 MPa...     

动态硫化BR/EVA/SBS/HIPS热塑性弹性体的增强研究

采用动态硫化法制备了顺丁橡胶(BR)/乙烯-醋酸乙烯共聚物(EVA)/苯乙烯-丁二烯-苯乙烯共聚物(SBS)/高抗冲聚苯乙烯(HIPS)热塑性弹性体(TPE),通过在BR中充填炭黑的方式对复合体系进行增强,对其力学性能及断面微观结构进行了研究。结果表明,对于动态硫化BR/EVA/SBS/HIPS共混型TPE,当BR相中炭黑填充量在0~80phr的范围内,其动态硫化产物均表现出TPE的特征;随着炭黑用量的提高,复合体系的拉伸强度、撕裂强度、邵氏硬度趋于显著提高,断裂伸长率趋于下降,而扯断永久形变则趋于不变;未填充炭黑TPE的拉伸断面上两相界面结合良好;炭黑填充后的TPE的断面起伏较大但平滑,表明弹性较强。     

SBS改性PP基导电复合材料

采用(苯乙烯/丁二烯/苯乙烯)共聚物(SBS)改性聚丙烯(PP)为基体,炭黑(CB)为导电填料制备了导电复合材料。研究了导电复合材料的电性能及力学性能;同时探讨了CB在PP/SBS基体中富集的相关影响因素。结果表明,在基体中加入质量分数为20%的SBS可以大幅提高同等CB含量下导电复合材料的电导率,增加材料的韧性;在CB质量分数仅为10%的情况下富集效果更为明显。     

苯亚磺酸钠在聚乙烯醇为粘合剂的光敏热成像材料中的化学增感

以水溶性聚乙烯醇(PVA)为粘合剂，以异位法制备的颗粒尺寸为100nm的AgBr乳剂作光敏元，考察了苯亚磺酸钠(SBS)的用量、增感时间和增感温度对光敏热成像(PTG)材料照相性能的影响．实验结果表明：分别增感硬脂酸银(AgSt)、AgBr或者两者混合物，PTG材料均可取得明显的增感效果；灰雾随着苯亚磺酸钠用量增加而增加；增感温度以及增感时间不同，PTG材料的感光度不同．     

SBS/Polyaniline or Carbon Black System: Finding the Optimal Process and Molding Temperatures Through Experimental Design

Summary: The optimum mixing and molding conditions for processing of styrene‐butadiene‐styrene (SBS) triblock copolymer filled with carbon black (CB) or polyaniline doped with dodecylbenzene sulfonic acid (Pani.DBSA) were determined. The mechanical performance of SBS/CB and SBS/Pani.DBSA composites were characterized in terms of strain and stress responses at break condition. In order to reach this goal, two mixed two‐ and three‐level factorial designs were employed. The obtained data show that the molding temperature is the most important parameter to affect the mechanical behavior of the systems. Among the systems analyzed, the SBS/Pani.DBSA blends presented the highest sensitivity to the process and molding conditions.

Elongation of composites as a function of molding temperature.     

干法纺黑色氨纶生产技术的研发

阐述了干法纺黑色氨纶生产技术的研究过程,介绍了相关生产工艺流程以及技术关键点,即采用高色素炭黑和超分散剂,选择适当的控制条件,研制出具有良好粒度分布(平均粒径约100 nm,最大粒径约400 nm)和着色性能的色浆。利用原液着色法,选择合适的炭黑添加量(相对氨纶丝质量分数约为0.5%),生产出符合干法氨纶纺丝要求的黑色原液,实现了黑色氨纶在现有生产线上的工业化生产。     

Carbothermal Reduction of the Molybdenum Oxide/Phenanthroline Complex

Samples of an MoO₃/phenanthroline complex and an MoO₃/carbon black mixture were heated below 1400°C in nitrogen to characterize the carbothermal reduction process of the complex. The conversion of crystalline phases by carbothermal reduction followed substantially the same process in both samples but occurred at a temperature 100° to 150°C lower in the complex than in the carbon black mixture. Two possible explanations for this difference are theorized: (1) The complex may provide more intimate contact between the MoO₃ and the intercalated reducing material. (2) The intercalated reducing agents may have a higher reactivity than does the carbon black.     

增容剂对PE-HD/PC/CB导电复合材料PTC效应的影响

研究了增容剂马来酸酐接枝聚乙烯(PE-g-MAH)、乙烯-醋酸乙烯酯(EVA)、苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)对高密度聚乙烯(PE-HD)/聚碳酸酯(PC)/炭黑(CB)复合材料导电性能的影响。结果表明,加入增容剂有利于增强复合材料的正温度系数(PTC)效应,其中嵌段共聚物SBS对复合材料PTC效应的改善效果相对较好,SBS含量为4%(质量分数,下同)时,复合材料的PTC强度最高,比未添加时提高了14.3%;接枝共聚物PE-g-MAH的加入对复合材料PTC效应的增强效果弱于SBS;无规共聚物EVA的加入对负温度系数(NTC)现象具有明显的抑制作用,使复合材料的NTC强度从0.3下降至0.08。     

氯化聚乙烯的研究与应用

综述了溶剂法、水相悬浮法和固相氯化法制备氯化聚乙烯(CPE)的特点。介绍了具有不同氯含量及结构的CPE性能及其在塑料、橡胶等领域的应用。重点阐述了在低密度聚乙烯／聚氯乙烯(PVC)、PVC／苯乙烯-丁二烯嵌段共聚物(SBS)、乙烯,乙烯-乙酸乙烯,炭黑共混体系和氯丁橡胶,甲基丙烯酸甲酯(MMA)、SBS／MMA接枝体系引入CPE对体系的增容、稳定、协同作用：以及CPE作为第三组分在高密度聚乙烯／PVC／CPE、苯乙烯-丙烯腈／CPE共混体系中对共混物形态、机械性能和流变性能的影响。     

Thermal Degradation Behavior of WOP2O7/Phenanthroline Complex

An intercalation compound of WOP₂O₇/phenanthroline and a mixture of WOP₂O₇/carbon black were prepared to have equal carbon contents. Both samples were heated below 1400°C under a nitrogen atmosphere and their thermal degradation behaviors compared, with the following results: (1) CO gas evolved through carbothermal reduction at a temperature 150°C lower in the intercalation compound than in the WOP₂O₇/carbon black mixture. (2) Both WP and W formed at temperatures approximately 100°C lower in the intercalation compound than in the mixture. (3) Thermal degradation occurred homogeneously throughout the intercalation compound particles, and the particle morphology remained favorable after thermal degradation.     

Preparation and mechanical properties of clay/polystyrene‐block‐polybutadiene‐block‐polystyrene triblock copolymer (SBS) intercalated nanocomposites using organoclay containing stearic acid

Organoclays containing various amounts of stearic acid (SA) were synthesized, and clay/polystyrene‐block‐polybutadiene‐block‐polystyrene triblock copolymer (SBS) intercalated nanocomposites were prepared using organoclays containing SA by melt‐blending. Montmorillonite was the clay used, and both stearylamine and SA were used as surface modifiers. The amount of SA added was 0, 20, 50 and 100% of the cation‐exchange capacity (CEC). In this study, the effects of SA on the microstructure and mechanical properties of the clay/SBS nanocomposites were investigated. In clay/SBS with 100% CEC of SA, although no exfoliation of the clay occurred, the stacked clay layers were uniformly dispersed at the nanometer level (100–800 nm) without agglomeration. Clay/SBSs containing SA exhibited superior mechanical properties compared to clay/SBS without SA. It was found that SA effectively improved the clay dispersion in the SBS matrix and the mechanical properties of the clay/SBSs. Copyright © 2006 Society of Chemical Industry