MBS核-壳粒子的内部结构对MBS/PVC光学性能的影响

以乳液聚合的方法合成了具有核-壳结构的MBS树脂。恒定MBS中M/B/S的比例为30/42/28,通过采用不同的引发体系及加料方式制备不同内部结构的橡胶粒子。将MBS树脂与聚氯乙烯（PVC）共混,研究了橡胶粒子的内部结构对共混物透光性的影响。用透射电子显微镜对共混物的形态进行了研究,MBS粒子分别具不同的包容物结构。研...     

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。     

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。     

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。     

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。     

PVC/SBS/MBS三元共混体系的力学性能及光学透明性研究

采用冲击实验、拉伸实验、超景深三维显微镜、扫描电镜和分光光度计等手段，对PVC／SBS／MBS三元共混体系的冲击强度、拉伸强度、形态结构以及光学透明性等进行了研究。实验结果表明，MBS能有效改善PVC／SBS共混体系的界面相容性。当SBS和MBS的总量不变时，随着MBS相对含量的增加，共混体系的缺口冲击强度逐渐增加，透光率在m（MBS）／m（SBS）=28／80时达到最大值，光学透明性能最好。     

新型核-壳改性剂N-AIM对PMMA性能的影响

通过乳液聚合方法制备了不同橡胶粒径和橡胶相组成比的新型核-壳丙烯酸酯类抗冲改性剂（N-AIM）,将其与聚甲基丙烯酸甲酯（PMMA）进行熔融共混,得到了PMMA/N-AIM共混物。对PMMA/N-AIM共混物的形态结构、冲击性能和光学性能分别进行了考察。通过透射电镜（TEM）分析表明,橡胶粒径为100 nm时改性剂在基体中发生聚集,大于100 nm时均可均匀分散在基体中;冲击测试结果表明,随着N-AIM橡胶粒径的增加,共混物的冲击强度先增大后减小;光学测试表明橡胶组成比影响共混物的光学性能。     

MBS对聚碳酸酯的增韧作用及其增韧机理的探讨

研究了甲基丙烯酸甲酯-丁二烯-苯乙烯共聚物（MBS）对光盘级聚碳酸酯的增韧作用。结果表明，MBS对PC增韧效果显著，且MBS分散性越好，根据逾渗理论，达到脆一韧转变时所需的MBS含量越少。求得达到脆-韧转变时的临界粒间距为50nm。对共混物损伤机制的研究表明，MBS增韧PC共混物的增韧机理为MBS粒子的空洞化引发基体的剪切屈服。     

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组成对PVC／MBS合金性能的影响

讨论了MBS的组成、粒径尺寸以及粒子结构等因素对PVC/MBS合金综合性能的影响，结果表明，当MBS组成为25/60/42时，与PVC树脂的相容性好，所得合金为折光指数匹配的透明材料，具有好的光学及力学性能。     

Toughening of polyvinylchloride by methyl methacrylate–butadiene–styrene core–shell rubber particles: Influence of rubber particle size

An analysis was made on the effects of rubber particle size on the mechanical properties and deformation mechanisms of transparent polyvinyl chloride (PVC) blends containing core–shell methyl methacrylate–butadiene–styrene (MBS) impact modifiers. The critical interparticle distance was found not to be the criterion for the brittle‐ductile transition in the blends. In tensile tests, the blends with larger (100–280 nm) rubber particles exhibited intense stress‐whitening, while one blend with small (83 nm) rubber particles showed only slight stress‐whitening. These differences were due to an increase in resistance to cavitation with decreasing rubber particle size. Transmission electron microscopy studies on blends with a bimodal distribution of particle sizes showed that in the whitened zone of Izod specimens the larger rubber particles cavitated and expanded on yielding, while the smaller particles remained intact. However, Izod test results showed that small MBS rubber particles can toughen the PVC matrix very effectively, especially at low temperatures and at low rubber concentrations. The deformation mechanisms responsible for these effects were discussed. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers     

Properties of rubber-toughened Polyvinyl chloride blends based on core-shell modifier with different particle morphology

Summary An analysis was made on the effects of particle morphology on the mechanical and optical properties of polyvinyl chloride/methyl methacrylate-butadiene-styrene (PVC/MBS) blends. Special care was taken to make comparisons of blends with different structural MBS under same conditions. The blend with a three-layer structure MBS had a lowest brittle-ductile transition (BDT) temperature, while the blend with a two-layer structure MBS had a relatively higher BDT temperature due to its higher Tg of rubber particles enhanced by combination of St. Furthermore, the transparency of blend with two-layer structure MBS was higher than that with three-layer structure MBS. In addition, SEM investigations showed the cavitation of rubber particles took place to remove the plastic constraint and promote a large volume of deformation in the blend with three-layer structure MBS.     

合成和应用过程中MBS微观结构的研究

为了考察MBS微观结构与其合成工艺、产品性能之间的关系，利用电子显微镜技术对丁苯胶乳、MBS接枝胶乳、MBS粉末颗粒、PVC／MBS共混物的微观形态进行了系统的研究分析；对PVC／MBS共混物经过拉伸后内部微观结构和冲击后的断面进行分析研究，初步探讨了MBS的抗冲改性机理。     

Effects of core‐shell particle growth manners on morphologies and properties of poly(vinyl chloride)/(methyl methacrylate–butadiene–styrene) blends

A series of methyl methacrylate‐butadiene‐styrene (MBS) core‐shell particles were synthesized by seeded emulsion polymerization. All the MBS particles are designed with the same defined chemical composition, which is a prerequisite for producing transparent blends with poly(vinyl chloride) (PVC). Three different growth manners of core‐shell particles: agglomeration of small styrene‐butadiene rubbers (SBRs) followed by styrene (ST) and methyl methacrylate (MMA) monomers grafting, agglomeration of small MBS particles and traditional MBS with single SBR rubber core, and ST/MMA shells are used. The effects of growth manners of MBS on the properties and deformation mechanism of PVC/MBS blends are studied. It is found that all the MBS particles can toughen the PVC matrix effectively, but different deformation modes are observed: cavitation in large particles, debonding at the PVC/MBS interface, rubber cavitation, and clusters of voids, respectively. In addition, it is found that the stress‐whitening extent is associated with the deformation modes. J. VINYL ADDIT. TECHNOL., 22:37–42, 2016. © 2014 Society of Plastics Engineers     

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.     

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。     

3-巯基丁酸酯对MBS树脂相相对分子质量及PVC/MBS力学性能的影响

通过添加3-巯基丁酸酯合成了一系列树脂相相对分子质量变化的甲基丙烯酸甲酯-丁二烯-苯乙烯三元共聚物(MBS树脂)。并将其与聚氯乙烯(PVC)树脂进行熔融共混,测试了PVC/MBS合金的力学性能。结果表明,链转移剂3-巯基丁酸酯用量越多,MBS树脂相的相对分子质量越低,PVC/MBS合金的熔体流动速率越高、加工流动性越好、冲击强度越低,但对拉伸强度影响不大。这对开发系列MBS树脂具有重要指导意义。