PVC／MBS共混物的相容性研究

根据ＭＢＳ核壳结构的特征，分析了与ＰＶＣ进行共混时两组分溶解度参数与相容性的关系，采用差示扫描量热法（ＤＳＣ），考察共混体系中玻璃化转变温度的变化，表明ＰＶＣ／ＭＢＳ体系的相界面具有较好相和粘合作用。用红外光谱法测定，发现了共混体系中ＰＶＣ－ＭＢＳ间氢键的存在，从而提高了组分的相容性。通过ＰＶＣ－ＭＢＳ片材的热粘合样品的切强度试验，也可观察它们界面的相容程度。     

共混合金力学性能的研究：Ⅲ.CPP对PVC共混体系力学性能的 …

将ＰＰ氯化后作为ＰＶＣ共混体系的刚性体分散相，旨在改善高分子合金的相容性，ＤＣＳ实验表明，ＣＰＰ与ＰＶＣ的相容性比ＰＶＣ与ＰＰ的好。在用弹性体增韧的ＰＶＣ／ＣＰＥ和ＰＶＣ／ＡＢＳ共混体系中加入刚性体ＣＰＰ后，随着ＣＰＥ、ＡＢＳ用量的增加，共混合金的冲强度增加，并且由刚性的ＣＰＰ的加入后产生的冲击强度最大值的幅也有所提高。其趋势是ＣＰＥ、ＡＢＳ用量越多，共混合金冲吉强度值达到最大值时所需ＣＰＰ的量越     

PMMA基核-壳型有机刚性粒子增韧改性R-PVC/CPE韧性体

探讨了经过特殊表征的ＰＭＭＡ基核－壳型有机刚性粒子对Ｒ－ＰＶＣ／ＣＰＥ体系的增韧和增强作用及其对加工流变性的影响。研究发现,适当粒径的核－壳型粒子与Ｒ－ＰＶＣ／ＣＰＥ基体共混,常温（２３℃）使基体的冲击强度和断裂伸长率得到提高,断裂强度、屈服强度、硬度和加工流变性也有改善,而在低温（－１０℃）时几乎无增韧效果。     

PVC／NBR（HNBR）／HDPE共混体系相容性研究（Ⅲ）共混体系动态力学行为和结晶行为研究

用ＤＭＡ和ＤＳＣ研究了ＮＢＲ和氢化ＮＢＲ对ＰＶＣ／ＨＤＰＥ共混体系的增容作用。由于增容剂在相界面与ＰＶＣ和ＨＤＰＥ所产生的作用改变了界面分子的作用形式，使体系中ＰＶＣ和ＨＤＰＥ相的内耗峰内移。而ＤＳＣ的结果表明，增容剂降低了体系中结晶相ＨＤＰＥ的熔点，说明增容剂增加了ＰＶＣ／ＨＤＰＥ的相容性。     

共混合金力学性能的研究 Ⅲ.CPP对PVC共混体系力学性能的影响

将ＰＰ氯化后作为ＰＶＣ共混体系的刚性体分散相，旨在改善高分子合金的相容性，ＤＳＣ实验表明，ＣＰＰ（氯化聚丙烯）与ＰＶＣ的相容性比ＰＶＣ与ＰＰ的好。在用弹性体增韧的ＰＶＣ／ＣＰＥ和ＰＶＣ／ＡＢＳ共混体系中加入刚性体ＣＰＰ后，随着ＣＰＥ、ＡＢＳ用量的增加，共混合金的冲击强度增加，并且由刚性的ＣＰＰ的加入所产生的冲击强度最大值的幅度也有所提高，其趋势是ＣＰＥ、ＡＢＳ用量越多，共混合金冲击强度值达到最大值时所需ＣＰＰ的量越多，增加的幅度也越大。ＣＰＰ对共混合金的拉伸屈服强度和断裂伸长率的影响比较小。     

PVC／NBR（HNBR）／HDPE共混体系相容性研究：（Ⅲ）共混体系…

用ＤＭＡ和ＤＳＣ研究了ＮＢＲ和氢化ＮＢＲ对ＰＶＣ／ＨＤＰＥ共混体系的增容作用。由于增容剂在相界面与ＰＶＣ和ＨＤＰＥ所产生的作用改变了界面分子的作用形式，使体系中ＰＶＣ和ＨＤＰＥ相的内耗峰内移。而ＤＳＣ的结果表明，增容剂降低了体系中结晶相ＨＤＰＥ的熔点，说明增容剂增加了ＰＶＣ／ＨＤＰＥ的相容性。     

氯化聚乙烯在EVA/SAN体系中的增容研究

采用氯化聚乙烯作为乙烯醋酸乙烯酯共聚物／苯乙烯丙烯腈共聚物共混体系的增容剂,用力学性能,电镜等方法研究了ＥＶＡ／ＣＰＥ／ＳＡＮ三元体系的相容性。结果表明,由于ＣＰＥ与ＥＶＡ,ＳＡＮ均有一定程度的相互作用,在ＥＶＡ／ＣＰＥ／ＳＡＮ三元体系中ＣＰＥ存在于ＥＶＡ,ＳＡＮ的界面以减小总的界面能而起了增容作用,从而使该三元体系具有良好的综合力学性能。     

共混合金力学性能的研究：Ⅱ.CPE,ACR对PVC共混体系力？…

在上文的基础上，对ＰＶＣ／ＣＰＥ／ＰＰ和ＰＶＣ／ＡＣＲ／ＰＰ三元共混体系的力学性能进行研究。结果表明，随着ＣＰＥ或ＡＣＲ用量的增加，不但共混合金的冲击强度增加，而且共混合金由刚性体ＰＰ增韧时所产生的最大值的幅度也有所提高，其趋势是ＣＰＥ或ＡＣＲ用量越多，产生最大值时刚性体分散相ＰＰ所需的量越多，同时冲击强度最大值增加的幅度也越大。     

PP／EPDM／CaCO2三元共混体系的脆韧转变研究

采用扫描电镜和材料力学性能试验方法研究了ＰＰ／ＥＰＤＭ／ＣａＣＯ３三元体系中ＣａＣＯ３的表面处理与其材料的缺口冲击韧性及产生脆韧转变现象之间的关系。实验结果及分析表明，体系中分散相颗粒周围向ＰＰ基体扩散，渗透或与之共结晶的ＥＰＤＭ部分是增韧ＰＰ的有效成分；     

PMMA,SAN改性PVC／CPE共混体的研究

研究了刚性聚合物对ＰＶＣ／ＣＰＥ共混体力学性能，冲击断面形貌及流变性的影响。结果表明，ＰＭＭＡ对ＰＶＣ／ＣＰＥ＝１００／１０，１００／１５体系，ＳＡＮ对ＰＶＣ／ＣＰＥ＝１００／１０体系都具有显著的增韧作用和一定的增强作用；初步的测定显示，刚性聚合物能改善共混熔体的流变性，促进ＰＶＣ／ＣＰＥ共混体系中ＣＰＥ网络结构的形成和分散性。     

Effect of nanoclay and SEBS-g-MA on the morphology and properties of immiscible poly(methyl methacrylate)/polystyrene blend

In recent years, nanoclays are being used as compatibilizer for various immiscible polymer blends. However, little work has been done on the morphology of immiscible polymer blends in presence of both the nanoclay and a reactive compatibilizer. Here, we report the synergistic effect of nanoclay and SEBS-g-MA on the morphology and properties of (70/30 w/w) PMMA/PS blend. Scanning electron microscopy study of the blend with various amount of nanoclay and SEBS-g-MA indicated a reduction in the average domain sizes (D) of dispersed PS phase in PMMA matrix compared to that in the pure blend. Addition of both SEBS-g-MA and nanoclay significantly lowered the D of PS in the blend compared to that with only SEBS-g-MA or clay. X-ray diffraction study and transmission electron microscopy revealed the presence of intercalated clay platelets in PMMA matrix, as well as, at the interface of the (70/30 w/w) PMMA/PS blend-clay nanocomposites. Addition of SEBS-g-MA in the blend-clay nanocomposites promoted the exfoliation of clays in PMMA matrix. Thus, exfoliated clay platelets in PMMA matrix effectively restricted the coalescence of dispersed PS domains while SEBS-g-MA improved the adhesion between the phases at the interface. At certain loading (phr), storage modulus, elongation at break and thermal stability of the blend were greatly improved when both the nanoclay and SEBS-g-MA were present in the blend. The use of reactive compatibilizer and nanoclay in polymer blends may lead to a high performance material which combines the advantages of compatibilized polymer blends and the merits of polymer nanocomposites.     

HA改性短切碳纤维/PMMA生物复合材料力学性能的研究

采用原位合成与溶液共混的方法,制备了纳米羟基磷灰石(HA)-短切碳纤维（C_f）/聚甲基丙烯酸甲酯(PMMA)生物复合材料, 研究了HA对HA-C_f/PMMA复合材料的力学性能和微观结构的影响. 采用万能材料试验机测试了HA-C_f/PMMA复合材料的力学性能,用X射线衍射仪（XRD）、透射电镜（TEM）、场发射扫描电子显微镜（FESEM）和红外吸收光谱仪(FT-IR)分析测试手段对材料的组成结构及断面的微观形貌等进行了测试和表征. 结果表明,采用卵磷脂改性后的HA纳米片与PMMA基体的界面结合性能得到了有效改善,显著提高了复合材料的力学性能;随着HA含量的增加,HA-C_f/PMMA复合材料的弯曲强度、拉伸强度、压缩强度、弯曲模量和拉伸模量均呈先增大后减小的趋势. 当HA含量在8wt%时,复合材料的力学性能最佳.     

Compatibilizing effect of mesoporous fillers on the mechanical properties and morphology of polypropylene and polystyrene blend

Polypropylene(PP)/Polystyrene(PS) (PP/PS = 80/20) blend with different types of fillers were prepared by using melt method. Four different types of fillers, namely mesoporous MCM-41 (without template), nano-SiO₂, Polymethylmethacrylate (PMMA)/MCM-41 and PMMA/SiO₂ were considered. For PMMA/MCM-41 filler, the synthesis of the filler consisting of entrapped strand of PMMA within the pores of mesoporous MCM-41 (without template) was described. The mechanical properties of the blend determined as the nano-fillers contents and the different types of blend were found to vary with the different interface between fillers and the matrix. SEM revealed a good interaction between the matrix phases and PMMA/MCM-41 or MCM-41 (without template). The decreased T_g of PS implied that the good adhesion between PP and PS blend was obtained by adding PMMA/MCM-41 nano-filler.     

Autophobicity-driven surface segregation and patterning of core-shell microgel nanoparticles

Core-shell microgel (CSMG) nanoparticles, also referred to as core-cross-linked star (CCS) polymers, can be envisaged as permanently cross-linked block copolymer micelles and, as such, afford novel opportunities for chemical functionalization, templating, and encapsulation. In this study, we explore the behavior of CSMG nanoparticles comprising a poly(methyl methacrylate) (PMMA) shell in molten PMMA thin films. Because of the autophobicity between the densely packed, short PMMA arms of the CSMG shell and the long PMMA chains in the matrix, the nanoparticles migrate to the film surface. They cannot, however, break through the surface because of the inherently high surface energy of PMMA. Similar thermal treatment of CSMG-containing PMMA thin films with a polystyrene (PS) capping layer replaces surface energy at the PMMA/air interface by interfacial energy at the PMMA/PS interface, which reduces the energy barrier by an order of magnitude, thereby permitting the nanoparticles to emerge out of the PMMA bulk. This nanoscale process is reversible and can be captured at intermediate degrees of completion. Moreover, it is fundamentally general and can be exploited as an alternative means by which to reversibly pattern or functionalize polymer surfaces for applications requiring responsive nanolithography.     

PMMA、SAN改性PVC/CPE共混体的研究

研究了刚性聚合物(PMMA、SAN)对PVC/CPE共混体力学性能、冲击断面形貌及流变性的影响。结果表明,PMMA对PVC/CPE=100/10、100/15体系,SAN对PVC/CPE=100/10体系都具有显著的增韧作用和一定的增强作用;初步的测定显示,刚性聚合物能改善共混熔体的流变性,促进PVC/CPE共混体系中CPE网络结构的形成和分散性。     

嵌段共聚物在共混体系中的增容作用研究II.PS-b-PMMA对PVC/SBS共混体系相态结构的影响

合成了一系列分子量和单体组成比不同的聚苯乙烯 -聚甲基丙烯酸甲酯两嵌段共聚物 ( PS- b- PMMA)作为PVC/SBS共混体系的增容剂。系统研究了 PVC/SBS的组成比、增容剂的用量以及增容剂的分子结构等因素与共混体系相态结构之间的关系。结果表明 ,增容剂的不同结构对共混体系的相态结构影响很大 ,在所合成的 4种增容剂中 ,分子量相对较小 ,分子内聚甲基丙烯酸甲酯嵌段的分子量与聚苯乙烯嵌段的分子量比较接近的增容剂分子 ,具有更好的增容效果 ,其增容的共混体系具有典型的韧性特征。     

Toughening of polystyrene by natural rubber-based composite particles: Part I Impact reinforcement by PMMA and PS grafted core-shell particles

This work was focused on the influence of the morphology of composite natural rubber (NR)-based particles on the toughness of polystyrene (PS). Emulsion polymerization processes were used to adjust the microstructure of the latex particles. In order to be suitable for the reinforcement of PS, the NR-based particles were coated with a shell of crosslinked polymethyl methacrylate (PMMA) or PS. Furthermore, PS subinclusions were introduced into the natural core. A continuous extrusion process was adapted for the incorporation of these natural rubber based impact modifiers into thermoplastics. High deformation speeds (impact testing) were necessary in order to evaluate the mechanical properties of PS blends with a series of the prepared structured latexes. PS could only be toughened by core-shell particles. A PMMA shell proved to be advantageous because it is easier to produce by emulsion polymerization than a hydrophobic PS shell. Pre-vulcanized NR-based particles, which do not cavitate easily, were ineffective. Core-shell particles based on NR-containing PS subinclusions toughened PS more effectively. Solid NR particles caused premature craze and polymer fracture, as the rubber particles break down, debond from the matrix and form large voids at the craze/particle interface. Scanning electron microscopy (SEM) of Izod fracture surfaces showed clearly the cavities of debonded solid rubber particles and demonstrated that subinclusions within the rubber core permitted a larger volume of plastic deformation before failure. This revised version was published online in November 2006 with corrections to the Cover Date.     

有机改性蒙脱土的制备及其对聚乙烯-聚苯乙烯相态和力学性能的影响

利用Gemini表面活性剂对蒙脱土进行插层改性制备得到有机改性蒙脱土（OMMT）,采用溶液混合法制备了OMMT/聚苯乙烯（PS）母料,将OMMT/PS母料与聚乙烯（PE）熔融共混制备得到OMMT/PS-PE复合材料。研究了蒙脱土的插层改性对OMMT/PS-PE复合材料相形态和力学性能的影响。对OMMT进行FTIR、XRD、TG表征,结果表明Gemini表面活性剂成功插层进入蒙脱土层间。通过SEM和电子万能试验机研究了OMMT/PS-PE复合材料相结构、分散相粒径的及相态与力学性能之间的关系。结果表明,随着OMMT含量的增加,PS分散相的粒径逐渐减小;当OMMT含量为2.5wt%时,OMMT/PS-PE复合材料的相形态由“海-岛”转变为双连续结构。与未添加OMMT的PE-PS树脂相比,OMMT/PS-PE复合材料弯曲模量和断裂伸长率显著提高,分别提高了约18%和近50倍。      

微悬浮法CaCO3表面接枝PMMA及其在PVC中的应用

在水介质中,超声作用下用油酸对纳米碳酸钙进行表面修饰,再以微悬浮原位聚合法用PMM A进行接枝包覆,成功制备了PMM A/C aCO3复合粒子。借助透射电镜(TEM)、红外光谱(FT-IR)、热失重(TG)等分析手段对复合粒子的形态结构进行了表征。实验结果表明,油酸可通过羧酸盐的形式吸附于碳酸钙粒子表面,一定量PMM A通过油酸分子的不饱和双键接枝于碳酸钙粒子表面。将所得PMM A/C aCO3复合粒子与PVC共混制得PVC/PMM A/C aCO3复合材料。复合材料的TEM照片表明,C aCO3粒子非常均匀地分散在PVC基体中,两相界面模糊。随着PMM A/C aCO3纳米复合粒子用量的增加,复合材料的强度和韧性同时提高。当复合粒子用量高于12%时,复合材料的冲击强度可提高3倍,而拉伸强度下降很少。     

ACR对其接枝VC悬浮树脂材料结构性能的影响

采用多步种子乳液聚合方法合成的核-壳聚丙烯酸酯(ACR)乳液与氯乙烯(VC)进行悬浮接枝共聚,详细讨论了ACR核壳比及乳液粒径对共聚树脂材料力学性能的影响,用透射电镜(TEM)和扫描电镜(SEM)对材料的结构进行了表征。TEM照片显示：ACR高度均匀地分散在PVC基体中,两者相容性较好;当3ACR乳胶粒径约为80nm时,共聚树脂的缺口冲击强度最佳,较纯PVC提高近7倍,试样断面呈现广泛密集的拉丝形貌,表现出材料的优良韧性。