MBS粒子尺寸对PVC／MBS共混物性能及形变机理的影响

通过乳液聚合方法制备了两种不同粒径（分别为270nm和80nm）的甲基丙烯酸甲酯/丁二烯/苯乙烯（MBS）核壳改性剂，与聚氯乙烯（PVC）进行熔融共混，得到了PVC／MBS共混物。对PVC／MBS共混物力学、光学等方面的性能及其形变机理分别进行了考察。结果表明：PVC／MBS共混物的脆-韧转变温度（BDT）和拉伸性能均随着MBS粉料粒径的增加而增加；但是光学测试则表明MBS粒子对改善PVC基体的光学性能的效果却随MBS粉料粒径的增加而降低；透射电镜（TEM）的分析表明大粒径的MBS粉料能促使橡胶粒子产生空洞化，而由小粒径的MBS粉料制备的PVC／MBS共混物没有观察到橡胶粒子空洞化的产生。     

苯乙烯在MBS中的结合方式对PVC/MBS性能的影响

以乳液聚合法合成了化学组成恒定的具有核-壳结构的(甲基丙烯酸甲酯/丁二烯/苯乙烯)共聚物(MBS),通过改变原料及其配比,使苯乙烯(St)在MBS中以共聚或接枝方式结合,用动态力学热分析仪研究了MBS内耗与温度的关系。将MBS与聚氯乙烯(PVC)共混,研究了St结合方式对共混物冲击韧性及增韧机理的影响,结果表明,随着MBS核中St含量的增加,PVC/MBS共混物的脆-韧转变向高温移动;当St仅以接枝的方式结合时,橡胶粒子的空洞化及剪切屈服是主要的增韧机理,当St仅以共聚方式结合时,剪切屈服是主要的增韧机理。     

MBS与PVC共混改性的研究

本文介绍了MBS与PVC共混改性的研究,找出了能制备综合性能较佳的MBS/PVC共混物的配方。用DSC法和扫描电镜分别研究上述两组分的相容性及所得共混物的相态结构。并就MBS中橡胶粒径,含胶量等对所制得的共混物冲击强度的影响进行了探讨。此外,用Brabender流变仪测定该共混物的流变曲线,预测其熔融加工情况。     

PVC/MBS共混物的形态及力学性能

采用种子乳液聚合方法,在聚丁二烯乳胶粒子上接枝甲基丙烯酸甲酯（MMA）和苯乙烯（St）,制得MBS核壳接枝共聚物,并将其作为增韧剂与聚氯乙烯（PVC）共混制备PVC/MBS共混物。考察了接枝不同MMA和St含量的MBS在PVC中的分散状态及其对PVC/MBS共混物力学性能。结果表明,当MBS壳层中MMA含量增加时,MBS粒子在PVC基体中的分散状态被改善;PVC/MBS共混物的冲击强度随之增加,冲击强度最高时为1117.74 J/m;当MBS中接枝少量St时,PVC/MBS共混物呈现韧性断裂,冲击值最高时为1039.33 J/m;当MBS接枝大量St时,会产生内包容现象,不利于提高PVC共混物的冲击强度。     

PVC/耐热改性剂共混体系的力学及耐热性能研究

以具有核壳结构的纳米级交联粒子为耐热改性剂,系统研究了聚氯乙烯(PVC)树脂/粒子耐热改性剂/甲基丙烯酸甲酯-丁二烯-苯乙烯共聚物(MBS)树脂三元共混体系的力学性能、维卡耐热性能及流变行为,探讨了刚性粒子和橡胶粒子在PVC树脂增韧和耐热改性过程中的相互作用及关键影响因素。结果表明:具有核壳结构的纳米离子型耐热改性剂可以显著提高PVC树脂的维卡软化温度,加入MBS树脂可提高共混物冲击强度。研究发现,PVC中加入8份MBS和15份耐热改性剂,可制得耐热、抗冲兼备的PVC共混新材料。     

核-壳结构粒子MBS增韧聚乳酸的性能研究

采用乳液聚合法合成核-壳结构粒子甲基丙烯酸甲酯-丁二烯-苯乙烯共聚物(MBS),进一步对聚乳酸(PLA)进行增韧改性,并以甲基丙烯酸甲酯-甲基丙烯酸缩水甘油酯共聚物P(MMA-co-GMA)作为共混体系的相容剂。通过力学性能测试、动态热机械分析仪、透射电子显微镜、扫描电子显微镜等手段研究了该共混体系的力学性能和微观形态。结果表明,随着MBS含量的增加,共混物的冲击强度显著提高,屈服应力逐渐降低;相容剂P(MMAco-GMA)的引入没有提高共混物的冲击性能,但是显著提高了拉伸强度。DMA结果表明,随着P(MMA-co-GMA)中GMA含量的增加,PLA的玻璃化转变温度逐渐上升,MBS壳层的玻璃化转变温度逐渐降低;TEM测试发现P(MMAco-GMA)加入后,核壳粒子在PLA中分散得更加均匀。对形变区的SEM观察发现MBS橡胶粒子发生空洞化,基体发生剪切屈服。     

MBS接枝共聚物对PMMA树脂的增韧研究

采用乳液聚合法在聚丁二烯（PB）乳胶粒子上接枝苯乙烯（St）和甲基丙烯酸甲酯(MMA),合成了一系列的MBS接枝共聚物（简称MBS）,将其与聚甲基丙烯酸甲酯（PMMA）进行熔融共混制备PMMA/MBS共混物,研究了PB及相对分子质量调节剂叔十二烷基硫醇（TDDM）含量对共混物力学性能和微观形态结构的影响。结果表明,随着MBS中PB所占比例的增加,共混物的冲击强度表现出先增大后减小的趋势,当PB所占比例为50 %（质量分数,下同）时,共混物的冲击强度达到200 J/m,而拉伸强度表现出上升的趋势;随着TDDM用量的增加,MBS的接枝率和接枝效率降低,导致共混物的冲击强度先增加后减小;随着MBS中PB所占比例的增加,接枝率的逐渐降低,MBS在PMMA基体中分散程度逐渐变差。     

MBS树脂核壳结构的改善对其性能的影响

通过改进甲基丙烯酸酯-丁二烯-苯乙烯（MBS）共聚物的核壳结构,制备了新型MBS树脂,提高了MBS/聚氯乙烯（PVC）共混物的抗冲击性能、耐老化性能及加工塑化性能。     

MBS壳的组成对PVC/MBS共混物性能的影响

通过改变原料及其配比合成了壳组成不同的MBS树脂。将MBS树脂与PVC进行熔融共混,研究了PVC/MBS体系的流变行为、冲击性能和动态力学性能。结果表明:MBS壳中丙烯酸丁酯、甲基丙烯酸丁酯含量越多,体系的加工性能越好、冲击强度越高、储能模量越低。     

MBS树脂增韧PC的研究

利用双螺杆挤出机制备甲基丙烯酸甲酯-丁二烯-苯乙烯（MBS）树脂与聚碳酸酯（PC）熔融共混物。通过SEM观察得出：随着MBS用量的增加，改善了MBS与PC的相容性；力学性能结果表明：MBS的加入，提高了PC／MBS合金的缺口冲击强度，但合金的拉伸强度降低；PC／MBS合金的断裂表明：MBS增韧PC的机理是基体的剪切屈服和粒子的空洞化。     

CPE与ACR或MBS协同增韧硬质PVC研究

本文研究了ＰＶＣ／ＣＰＥ／ＡＣＲ或ＭＢＳ共混物的力学性能与增韧剂组成比、加工条件和相形态之间的关系。实验结果表明,适宜组成比和加工条件下,ＣＰＥ与ＡＣＲ或ＭＢＳ对硬质ＰＶＣ有协同增韧作用,共混物形态结构以增韧剂呈精细网－岛相分散为特征。     

二氧化硫凝聚MBS胶乳研究

提出了用二氧化硫凝聚MBS胶乳的新方法,研究了各种因素对凝聚时间、颗粒粒径分布和粉体堆积密度的影响,确定了最佳工艺条件:MBS胶乳的质量浓度为80～120g/L,凝聚温度50～60℃,搅拌速度200r/min,二氧化硫体积流量25 L/min.经8 m3凝聚釜生产试验,所得样品有较好的形貌,颗粒多为圆球;堆密度0.42;粒度分布集中,40和180目之间的颗粒含量达96%.PVC/MBS合金性能测试结果表明,由于塑化时间缩短,抗冲强度和透光率也得到了改善.     

Functional MBS impact modifiers for PC/PBT alloy

Functional group containing MBS impact modifiers for the poly carbonate/poly(butylene terephthalate (PC/PBT) alloy were synthesized and characterized in this study. The novel MBS consisted of three layers, in which the inner, middle, and outer layers were styrene butadiene rubber (SBR) latex, polystyrene, and a copolymer of the methacrylic acid (MMA) and the functional group containing vinyl monomer, respectively. Three different kinds of the functional monomers were used in this study, glycidyl methacrylate (GMA), acrylamide (AAM), and MAA. The functional group was used to improve the adhesion between the MBS and the PC/PBT alloy. Our results showed that the layer composition of the MBS exhibited a significant effect on the impact strength. A large variation of the impact strength from 14.1 to 23.6 ft‐lb/in. was observed when the SBR content increased from 30 to 70%. An optimum amount (4–6%) of the functional monomer enhanced the adhesion between the MBS and the PC/PBT alloy and thus improved the impact strength. Furthermore, a much smaller amount of the functional group containing MBS in the PC/PBT alloy than the conventional MBS could obtain an impact strength as high as 25.2 ft‐lb/in. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1280–1284, 2000     

Scanning electron micrograph study of the impact-improved MBS/PVC blends

The improvement of the impact strength of the telecommunication equipment using injection moldable PVC/MBS and other modifiers were studied. The addition of MBS to the PVC was found with rapid increases in the impact stregths in Kg-cm/cm: 5.5 of pure PVC; 80 of 12 phr and the maximum of 131 of 20 phr of MBS. This increasing impact strength phenomena were subjected to close examinations of SEM, DMTA, and strain-stress diagrams. The DMTA analysis of the retaining of the individual T_g's of MBS and PVC in the MBS/PVC blends, indicates that no miscibility of MBS and PVC has occurred. The DMTA diagrams of 5, 12, 20, and 30 phrs of MBS in PVC were analyzed and the same samples were also subjected to the impact strength measurements and the SEM examinations. SEM photos showed a gradual transition of the linear to the three-dimensional arrangements had occurred in the PVC/MBS blends. The formation of three-dimensional arrangement occurred between 10–20 phr of added MBS. The spacial change from linear to the three-dimensional arrangements observed in SEM photos correlates the rapid increases of the impact strengths of the specimens tested. Injection specimens of the telephone sets made of PVC/MBS blends with 20 phr of MBS in PVC indicate that the impact strength is averaged at 115 Kg-cm/cm with tensile strength of 330 Kg/sq cm and elongation of 150%. The similar change of the spacial arrangement is also observed in their SEM photos.     

Effect of morphology and refractive index on toughness and clarity balance of MBS modified vinyl bottles

Impact modifiers are used to enhance the toughness of rigid vinyl by providing a dispersed rubbery phase to absorb impact energy and prevent fracture of the otherwise brittle matrix. MBS impact modifiers are complex core//shell polymer structures based on specially prepared butadiene/styrene rubber latices with multiple stages of acrylic and other polymers grafted to them. In addition to providing a rubbery dispersed phase to improve to improve the toughness of vinyl, these structures also maintain clarity by matching the refractive index of the rubber particles with that of the vinyl matrix. Data will be present showing the effect of the rubber morphology, particle size and refractive index on the balance of impact strength and clarity of MBS modified vinyl packaging formulations.     

MBS结构剖析

本文用透射电镜，核磁共振和动态粘弹谱等近代测试仪器，对日本钟渊公司牌号Ｂ－３１和日本吴羽公司牌号ＢＴＡ的ＭＢＳ树脂进行了剖析，对其颗粒大小，颗粒形态和内部结构等进行了观察和测试，为ＭＢＳ的合成和应用提供了有益的依据。     

乳化剂对合成MBS树脂和PVC/MBS合金力学性能的影响

通过调节乳化剂十二烷基苯磺酸钠（SDBS）的用量合成MBS树脂，并将其与聚氯乙烯（PVC）树脂进行共混，测试PVC／MBS合金的力学性能。测试结果表明：乳化剂的用量越多，MBS树脂相的相对分子质量越低，PVC／MBS合金的拉伸强度变化不明显，其冲击强度先增大后减小。     

MBS树脂复合改性研究进展

分别对MBS树脂复合改性PVC、PC、PC/PBT及MS类树脂的行为进行了讨论,研究了不同改性剂的组分要求,并对改性前后的性能进行了对比评价。