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。     

悬浮法EPDM-g-MS/PS的冲击和耐候性能的研究

以三元乙丙橡胶(EPDM)、甲基丙烯酸甲酯(MMA)和苯乙烯(St)为原料,采用悬浮接枝共聚法合成了EPDM接枝MMA-St共聚物(EPDM-g-MS),再与聚苯乙烯(PS)树脂共混制备了EPDM-g-MS/PS(MES)高抗冲塑料。研究了接枝体系的单体配比(fMMA)和接枝产物所含MMA-St共聚物的共组成质量比(FMMA)对MES的缺口冲击强度的影响,以及MES的相结构与增韧机理、热稳定性和耐候性,并与苯乙烯-丁二烯-苯乙烯共聚物(SBS)/PS的性能进行了比较。结果表明:当fMMA为15%、FMMA为29.1%时,EPDM-g-MS对PS的增韧效果最好;当MES所含EPDM质量分数为30%时,其缺口冲击强度高达45.1 kJ/m2;在MES的微观结构中,橡胶相EPDM以具有包藏结构的分散相存在,MES的增韧机理为裂纹分支终止兼有轻度基体剪切屈服;而在SBS/PS中,橡胶相(聚1,4-丁二烯嵌段)以网络状连续相存在,其增韧机理为基体剪切屈服。MES的热稳定性和耐气候老化黄变性能显著高于SBS/PS。     

核壳型MBS增韧PC研究

利用双螺杆挤出机制备了核壳结构的甲基丙烯酸甲酯-丁二烯-苯乙烯塑料(MBS)与聚碳酸酯(PC)的熔融共混物。研究了MBS对PC/MBS合金常温力学性能和低温缺口冲击强度的影响;利用原子力显微镜观察了MBS在PC/MBS合金中的分布形态;扫描电子显微镜观察表明,MBS增韧PC的机理符合空穴理论。     

PVC/MBS/埃洛石纳米管复合材料的制备及其性能

采用熔融共混法制备了聚氯乙烯(PVC)/甲基丙烯酸甲酯-丁二烯-苯乙烯共聚物(MBS)/埃洛石纳米管(HNTs)三元复合材料,研究了HNTs对PVC/MBS共混体系力学性能、热性能和微观结构的影响。结果表明:HNTs与MBS可协同增韧PVC,使复合材料的强度和刚性得到改善,当HNTs的填充量为3 phr时,PVC/MBS(100/3)共混体系的冲击强度、拉伸强度、弯曲强度和弯曲模量分别提高了57.7%、12.1%、7.6%和45.9%;其冲击断面呈现韧性断裂特征;TEM观察结果发现,HNTs在PVC/MBS共混体系中具有良好的分散状态;热失重分析显示,HNTs对PVC/MBS共混体系热稳定性的提高能起到一定作用。     

PVC/SAN/ABS共混物的增韧机理

采用以乳液聚合的方法合成丙烯腈-丁二烯-苯乙烯共聚物(ABS)接枝粉料,将其与PVC、苯乙烯/丙烯腈共聚物（SAN）树脂熔融共混制备PVC/SAN/ABS共混物。恒定共混物中ABS含量,改变体系中SAN与PVC的比例从70.5/17.5至18/70。TEM分析表明,当共混物中SAN含量较多时,可以观察到银纹的存在;当共混物中PVC含量较多,可以观察到剪切屈服的发生;SEM分析发现,当共混物中PVC含量较多时,断裂表面出现了大量的空洞并伴随着基体的塑性流动;SAXS分析表明,当共混物中SAN的含量较多时,散射强度的增加是银纹的贡献能力增大的结果。     

PEB-g-MAN增韧SAN树脂的力学性能及增韧机理的研究

用悬浮接枝共聚合法合成了乙烯/1-丁烯共聚物（PEB）与甲基丙烯酸甲酯(MMA)/丙烯腈(AN)的接枝共聚物（PEB-g-MAN）,并用其增韧苯乙烯/丙烯腈共聚物（SAN）。研究了SAN/PEB-g-MAN共混物的力学性能、增韧机理和相结构。结果表明：PEB-g-MAN是SAN树脂的优良增韧剂,当PEB用量为25 %时,SAN/PEB-g-MAN的缺口冲击强度达63.3 kJ/m2,约为SAN树脂的60倍。SAN/PEB-g-MAN共混物在PEB含量为15 %-20 %时发生脆韧转变。脆韧转变前、脆韧转变过程中和脆韧转变后的冲击断面形态的SEM分析表明,共混物的增韧机理先是裂纹支化终止和空穴化,随后为高度空穴化,再为基体剪切屈服兼空穴化,最后转变为空穴化为主,剪切屈服为辅。TEM分析表明,PEB均匀分散于SAN连续相中,两相界面模糊,具有良好的相容性,且随着PEB含量的增加,共混物的相结构由"海-岛"结构转变为"双连续相"结构。     

环氧官能化ABS增韧PBT及其共混物

合成了甲基丙烯酸环氧丙酯(GMA)接枝的丙烯腈-丁二烯-苯乙烯(ABS-g-GMA)核壳粒子增韧聚对苯二甲酸丁二醇酯(PBT),加入环氧树脂(Epoxy)为扩链剂进一步提高共混物的性能。红外光谱(FTIR)结果表明:GMA成功接枝到ABS粒子上;研究发现不同GMA含量的ABS-g-GMA粒子在PBT及PBT/Epoxy共混物中均匀分散;ABS-g-GMA对PBT增韧效果较好,Epoxy进一步提高了PBT/ABS-g-GMA共混物的冲击韧性及拉伸强度;ABS-g-GMA增韧PBT的机理是橡胶粒子的空洞化和PBT基体的剪切屈服。     

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。     

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。     

Core–shell particles designed for toughening poly(vinyl chloride)

A novel core–shell modifier (MOD) made up of polystyrene and poly(butyl acrylate) (PBA) grafted on a crosslinked styrene‐co‐butadiene core was synthesized by emulsion polymerization. This modifier was used for enhancing effectively the impact ductility of poly(vinyl chloride) (PVC) without losing its transparency. The effects of the MOD on the properties of PVC/MOD blends were explored. It was found that the butyl acrylate (BA) content of the MOD was an important factor affecting the properties of PVC/MOD blends. The Izod impact strength of these blends reached 1200 J m^?1 when the MOD contained 40 wt% BA. The dispersion morphology of the MOD in the PVC matrix was investigated using transmission electron microscopy, with a uniform dispersion of the MOD with higher BA content being obtained. The toughening mechanism of PVC/MOD blends was also investigated. The presence of BA in the MOD enhanced the ductility of the PVC blends due to the increased amount of soft phase (PBA). The dispersion morphology indicated that the interfacial interaction between MOD particles and PVC matrix was improved due to the presence of PBA graft chain in the MOD. TEM of impact fracture samples showed that shear yielding of the PVC matrix and debonding of MOD particles were the major toughening mechanisms for the PVC/MOD blends. Copyright © 2010 Society of Chemical Industry     

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。     

Phase morphology and dynamic mechanical behavior for MIS toughened polyvinyl chloride

Graft copolymers of isoprene (Is), styrene (St), and methyl methacrylate (MMA) monomers (MIS) with typical core–shell structure were synthesized by seed emulsion polymerization and used as a toughening agent for preparation of polyvinyl chloride (PVC)/MIS blends. The St and MMA monomers were separately grafted on the cross‐linked poly‐isoprene rubber core. The toughness, sub‐micro‐morphology, and dynamic mechanical behavior of the blends were characterized by impact machine, scanning electron microscopy (SEM), and dynamic mechanical analyzer. The results showed that the impact strength of the blends was optimized when the content of MIS in PVC/MIS blends was kept at a constant value of 8 wt %, while the content of Is in MIS was 70 wt %. SEM morphologies of impact fractured surface showed that the PVC/MIS blends were typical ductile fracture because of the toughness effect of rubber particles, which correlated well with the mechanical properties. Under the same rubber content condition, the curves of the dynamic mechanical behavior of MIS toughened PVC blends appeared a more obvious rubber peak, indicating that the rubber content of MIS was higher than that of methyl methacrylate–butadiene–styrene (MBS), which explained the better toughening effect of MIS compared with MBS. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Fracture and impact strength of poly(vinyl chloride)/methyl methacrylate/butadiene/styrene polymer blends

The Izod impact strength of poly(vinyl chloride)/methyl methacrylate/butadiene/styrene(PVC/MBS)polymer blends can be changed significantly with different levels of MBS and/or MBS particle size. The following results were obtained by investigating the fracture of PVC/MBS test specimens: (1) The dependence of the Izod impact strength of PVC/MBS blend on MBS particle size confirms a maximum around a MBS particle size of 2000 Å. When MBS particle size is smaller than 2000 Å, the Izod impact strength increases with MBS particle size, and crazing occurs mainly in this region. When MBS particle size is larger than 2000 Å, then the Izod impact strength, in contrast, decreases with increasing MBS particle size, and both crazing and shear yielding occur, mainly in this region. (2) Tensile experiments of PVC/MBS blends carried out under various conditions showed that the amount of energy absorption increases with decreasing MBS inter-particle distance and with increasing MBS particle size when crazing is the main energy absorbing mode. The MBS inter-particle distance dominates the energy absorption when shear yielding is the main energy absorbing mode. (3) Therefore, the Izod impact strength of PVC/MBS blends and the maximum around a MBS particle size of 2000 Å can be explained as follows: Below 2000 Å, the energy absorption by crazing dominates the total energy absorption, and the energy absorption by crazing increases with MBS particle size. Above 2000 Å, the energy absorption by shear yielding is dominant, and the energy absorption by shear yielding increases with decreasing inter-particle distance, that is to say, decreasing MBS particle size.     

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...     

Synergistic effect of dual rubber system in toughening styrene maleic anhydride copolymers

Styrene maleic anhydride (SMA) copolymers were toughened by blending with two distinctly different rubber modifiers: styrene‐butadiene‐styrene (SBS) block copolymer and methacrylated butadiene‐styrene emulsion‐made graft copolymer (MBS). The modifiers were used both individually and in combination for the examination of their roles in toughening SMA. SMA was miscible with poly(methylmethacrylate) shell of MBS, whereas it was partially miscible with the polystyrene (PS) phase of SBS. When 40–50% of SBS was used in blends, the PS phase of SBS became immiscible with SMA. SBS did not improve the Izod impact strength of SMA appreciably. A prominent synergistic toughening effect was experimentally observed when SBS and MBS were used in combination in brittle SMA. This effect may be attributed to the fact that the large SBS particles initiate crazes and small MBS particles with good adhesion to SMA matrix improve the ligament thickness, which may play a critical role in craze growth and termination. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2260–2267, 2003     

High‐impact toughness poly(vinyl chloride)/(α‐methylstyrene)‐acrylonitrile‐butadiene‐styrene copolymer/acrylic resin blends: Thermal properties and toughening mechanism

High impact toughness poly(vinyl chloride) (PVC)/(α‐methylstyrene)‐acrylonitrile‐butadiene‐styrene copolymer (70/30)/acrylic resin (ACR) blends were prepared. Incorporation of ACR did not play a negative role in thermal properties. The glass transition temperature, heat distortion temperature, and thermal stability remained constant as ACR content increased. With the addition of 10 phr (parts by weight per hundred parts of resin) of ACR, the impact strength increased by 20.0 times and 7.2 times compared with that of pure PVC and that of PVC/(α‐methylstyrene)‐acrylonitrile‐butadiene‐styrene copolymer (70/30) blends, respectively. However, tensile strength and flexural properties decreased. The morphology changed from domain distortions to crazing with fibrillar plastic deformation as ACR content increased. The toughening mechanism varied from “shear yielding” to “craze with shear yielding,” which depended on the content of ACR. This study presents the finding that addition of ACR drastically improved impact toughness without sacrificing any heat resistance, and the enhanced impact strength could be at the same level of supertough nylon. J. VINYL ADDIT. TECHNOL., 21:205–214, 2015. © 2014 Society of Plastics Engineers     

MBS改性PVC性能研究

研究了不同牌号的(甲基丙烯酸甲酯/丁二烯/苯乙烯)共聚物(MBS)对聚氯乙烯(PVC)性能的影响,以及MBS各牌号之间的协同效应,同时对共混工艺及折白现象进行了探讨。结果表明,MBS单独使用时,以B51综合性能最佳,B521和BTA717的效果较差;B51单独使用时,折白现象明显;B521/B51、CH303/B51体系的质量比为2∶6时协同效果较好,且体系透明性优于B51,折白现象中等;MBS的投料温度为80℃时,体系的综合性能较优。