弹性体/刚性粒子协同增韧PVC研究

研究了不同组成的聚氯乙烯(PVC)树脂/耐热改性剂/(甲基丙烯酸甲酯/丁二烯/苯乙烯)共聚物(MBS)复合体系的力学性能和耐热性能,用扫描电子显微镜分析共混材料的冲击断面微观形态,用动态热机械分析仪测定其动态热力学性能.结果表明,在PVC中添加8份MBS、10份耐热改性剂时共混材料的力学性能和耐热性能达到一个均衡值,冲击断面出现了明显的"须根"现象,PVC材料由脆性断裂转变为韧性断裂,二者协同作用既提高了共混材料的韧性,又改善了其耐热性能.     

聚氯乙烯增韧改性剂的合成及共混改性研究

采用传统的乳液接枝聚合方法合成了以交联聚丙烯酸酯弹性体为核，聚氯乙烯（PVC）直接为壳层的新型聚氯乙烯复合改性剂，用于通用聚氯乙烯的增韧改性。通过粒径分析仪、透射电镜、动态力学分析等手段对复合粒子及其共混改性PVC材料进行了表征与测试。结果表明复合粒子具有核壳结构，粒径分布较窄；动态力学分析显示；改性剂的加入有效地改善了改性剂与PVC基体问的相容性；当改性剂加入量为6％（核壳质量比为50／50）时，改性PVC材料的缺口冲击强度为纯PVC的5倍。     

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。     

滑石粉有机高分子化改性及在PVC中应用

无机粒子经甲苯二异氰酸酯(TDI)和丙烯酸羟丙酯(HPA)表面修饰，分别接枝包覆聚甲基丙烯酸甲酯(PMMA)层和甲基丙烯酸甲酯一丙烯酸丁酯共聚物(PMMA-Co-PBA)层，构成复合粒子。通过傅立叶变换红外光谱仪(FTIR)、差示扫描量热仪(DSC)及扫描电子显微镜(SEM)等方法检测，确认了它们的形态结构，研究了它们混配成聚氯乙烯(PVC)材料的力学性能和韧化机制。结果表明：其最大拉伸强度、冲击强度数值比未经包覆处理的对照组有所提高，提高率分别达到136％和162％，可作为新型强韧化填充改性剂用于PVC电缆料。     

ACR/纳米SiO2复合粒子的合成及其对PVC的增韧作用

研究了细乳液聚合制备ACR/纳米SiO2复合粒子及其对PVC的增韧作用。对丙烯酸酯单体中的纳米SiO2粒子进行偶联改性,提高了ACR对纳米粒子的包覆率和接枝率,复合粒子与PVC共混后纳米SiO2粒子在PVC基体中的分散性好。复合粒子对PVC的增韧效果明显优于纳米SiO2粒子和未改性ACR共聚物,复合粒子的用量较少时,就可明显提高PVC的冲击强度。     

异戊二烯-丙烯酸酯类共聚弹性体的制备及其对PVC的增韧作用

研究了苯乙烯(ST)、甲基丙烯酸甲酯(MMA)为壳层单体,丙烯酸丁酯(BA)、异戊二烯(IP)、丙烯酸(AA)为核单体,以乳液聚合工艺制备共聚乳液和弹性体树脂,制备了共聚树脂与PVC的共混材料。研究了乳化剂、引发剂、反应温度对弹性体特征黏度的影响,对共聚物结构进行了表征,并测试了共混材料的流变性能和机械性能。结果表明:乳化剂4.5%,引发剂0.5%时,其共聚物的特性黏度最高。当m(共聚弹性体)∶m(PVC)=10∶100时,冲击强度达到了48.67 kJ.m-2。     

辐照交联PVC/没食子酸环氧树脂复合发泡材料的制备及性能

以聚氯乙烯(PVC)为基体树脂、没食子酸环氧树脂(GA-EP)和顺丁烯二酸酐(MA)为改性剂、偶氮二甲酰胺(ADC)为发泡剂,采用熔融共混法和辐照交联技术制备了一系列PVC/GA-EP/MA复合发泡材料。采用傅里叶变换红外光谱仪(FTIR)和核磁共振仪(¹H-NMR、¹³C-NMR)表征了GA-EP的化学结构;利用凝胶测试仪、万能试验机和扫描电子显微镜(SEM)等仪器,研究了GA-EP/MA(GM)固含量对PVC/GA-EP/MA复合发泡材料性能的影响。结果表明,与纯PVC发泡材料相比,GM固含量为8%的PVC/GA-EP/MA复合发泡材料凝胶含量、拉伸强度、压缩强度、压缩模量和硬度分别增大了9.6%、38.8%、31.0%、24.9%和11.9%,同时具有较好的泡孔结构。     

AN含量对PVC/SAN共混物相容性的影响

采用乳液聚合技术合成了一系列不同丙烯腈（AN）含量的苯乙烯-丙烯腈（SAN）共聚物,将其与聚氯乙烯（PVC）熔融共混,形成PVC/SAN共混物,并引入增塑剂邻苯二甲酸二辛酯（DOP）。通过动态力学分析仪（DMA）和扫描电子显微镜（SEM）对共混物的玻璃化转变温度和相结构进行表征,考察不同AN含量对PVC/SAN共混物相容性的影响。     

ACR-g-St的制备及对PVC增韧

采用乳液聚合法制备了苯乙烯改性的核壳结构丙烯酸酯增韧剂(ACR-g-St),将其与聚氯乙烯(PVC)共混制备了增韧PVC共混物,采用动态热机械分析和扫描电镜等方法研究了PVC/ACR-g-St共混体系力学性能和相结构。结果表明,PS能增加PVC与ACR-g-St二者间的分子链缠结,当ACR-g-St用量为8phr时,PVC共混物的冲击强度为950J/m,是韧性断裂;扫描电镜照片表明ACR粒子在PVC基体中分散均匀。     

AIM增韧剂的合成及其增韧PVC的研究

采用种子乳液聚合法合成了核-壳结构丙烯酸酯类冲击改性剂(AIM),并用其增韧聚氯乙烯(PVC)树脂。采用动态激光粒度分析仪、DMA测试了AIM的乳胶粒子尺寸和玻璃化转变温度。对PVC/AIM共混物力学性能的分析表明:当PVC/AIM=100/8时,通过调节AIM交联剂含量和粒子尺寸,可以使PVC/AIM共混物冲击强度达到1443J/m。     

Preparation and characterization of poly(butyl acrylate‐co‐2‐ethylhexyl acrylate) grafting of vinyl chloride resin with good impact resistance

Crosslinked poly(butyl acrylate‐co‐2‐ethylhexyl acrylate) [P(BA–EHA)] latex was synthesized by seeded emulsion polymerization. P(BA–EHA)/poly(vinyl chloride) (PVC) composite latex was prepared using P(BA–EHA) latex as the seed. The effects of the amount of P(BA–EHA) on the latex particle diameters and mechanical properties of the materials are discussed. The grafting efficiency (GE) of P(BA–EHA)‐grafted vinyl chloride (VC) in the synthesized resin was investigated, and the GE increased with an increasing P(BA–EHA)/VC ratio. The morphology of P(BA–EHA)/PVC was characterized using TEM, SEM, and DMA. TEM indicated that the particles of the P(BA–EHA)/PVC composite latex have a clear core–shell structure. DMA illustrated that the compatibility between P(BA–EHA) and PVC was well improved. With an increasing P(BA–EHA) content, the loss peak in the low‐temperature range became stronger than that of pure PVC, and the maximum values of the loss peaks gradually shifted to higher temperature. SEM showed that the fractured surface of the composite sample exhibited better toughness of the material. The notched impact strength of the material with 4.2 wt % P(BA–EHA) was 11 times that of PVC. TEM showed that P(BA–EHA) was uniformly dispersed in the PVC matrix and that the interface between the two phases was indistinct. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 643–649, 2003     

Synthesis and characterization of poly(butyl acrylate‐co‐ethylhexyl acrylate)/ poly(vinyl chloride)[P(BA‐EHA)/PVC] novel core‐shell modifier and its impact modification for a poly(vinyl chloride)‐based blend

Synthesis of poly(butyl acrylate‐co‐ethylhexyl acrylate)‐core/poly(vinyl chloride)‐shell [P(BA‐EHA)/PVC] used as a modifying agent of PVC via semicontinuous seeded emulsion copolymerization is reported here. Diameter distributions and morphology of the composite latex particles were characterized with the aid of particle size analyzer and transmission electron microscopy (TEM). The grafting efficiency (GE) and grafting ratio (GR) of vinyl chloride (VC) grafted onto the P(BA‐EHA) with varying content of crosslinking agent and core‐shell ratios were investigated. TEM studies indicated that the P(BA‐EHA)/PVC latex particles have core‐shell structure, and the P(BA‐EHA) rubbery particles in blending materials were uniformly dispersed in PVC matrix. Dynamic mechanical analysis (DMA) results revealed that the compatibility between the P(BA‐EHA) and the PVC matrix was significantly improved due to the presence of the P(BA‐EHA)‐grafted‐VC copolymer. The notched impact strength of the blending material with 3 wt% of rubber content was seven times that of the PVC. Linear regressions of mechanical properties as loading of the modifier were made. The resulting data of notched impact strength and elongation at break for the blending materials deviated significantly from regression lines within 3–4.5 wt% of the P(BA‐EHA) content. The PVC blends modified by the modifier exhibited good toughness and easy processability. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers     

PVC／ABS共混体系的相容性与形态结构研究

采用种子乳液聚合技术在聚丁二烯（PB）乳胶粒子上接枝共聚苯乙烯（St）、α-甲基苯乙烯（α—MSt）和丙烯腈（AN）单体,合成了一系列不同AN结合量的ABS和α—MABS接枝共聚物。将其与聚氯乙烯（PVC）树脂熔融共混制得了PVC／AtkS共混物,利用扫描电镜（SEM）、透射电镜（TEM）和动态力学分析仪（DMA）对共混物的相容性和相结构进行了表征。结果发现,在PVC／ABS共混体系中,尽管改变接枝SAN共聚物的AN结合量,PVC和ABS接枝共聚物均为不相容体系;在ABS接枝共聚物中引入α-MSt后,当接枝SAN共聚物的AN结合量为18．7％～23．6％（质量分数）时,共混物在室温以上只存在1个tanδ峰,共混物成为相容体系,当AN结合量达到32．1％（质量分数）时,共混物成为部分相容体系。共混物的相区尺寸明显地依赖于接枝SAN共聚物中的AN结合量,与动态力学性能结果表现出良好的吻合。     

Preparation and characterization of composite resin by vinyl chloride grafted onto poly(BA-EHA)/poly(MMA-St)

Crosslinked poly(butyl acrylate-co-2-ethylhexyl acrylate)/poly(methyl methacrylate-co-styrene) (ACR I) latex was synthesized by multi-stage emulsion polymerization. A series of grafting vinyl chloride (VC) composite latices were prepared by emulsion copolymerization in the presence of core-shell ACR I latex. The effects of ACR I amount and its core/shell ratio on particle diameters of the composite latices and mechanical properties of the prepared materials were investigated. The grafting efficiency (GE) of VC grafted onto ACR I increases with an increasing ACR I content. Transmission electron microscope (TEM) study indicates that ACR I latex particles have a regular core-shell structure obviously. However, when styrene content in the shell of ACR I is more than 70 percent of the shell by weight, ACR I latex particles have an irregular core-shell morphology like sandwich. The composite latex particles synthesized by core-shell ACR I latex grafting VC have a clear three-layered core-shell structure. Dynamic mechanical analysis (DMA) study reveals that the compatibility between ACR I and PVC is well improved. With increasing ACR I content, the loss peak in low temperature range for every composite sample becomes stronger and stronger and gradually shifts to a higher temperature. Scanning electron microscope (SEM) graphs showed that the fractured surface of the composite sample exhibited better toughness of the material. TEM graphs showed that ACR I was uniformly dispersed in the PVC matrix.     

固相法氯化聚乙烯与聚氯乙烯共混物的形态与性能

研究了聚氯乙烯(PVC)与固相法氯化聚乙烯(CPE)共混物的应力-应变行为和冲击强度对CPE用量和氯含量的依赖关系,考察了共混物形态与性能的关系。动态力学性能和透射电子显微镜的研究结果表明,PVC/CPE为部分相容体系,两相间存在着一定的相互作用,当CPE氯含量为36％～42％,用量为7～15份时,CPE在PVC/CPE共混物中形成比较完整的网络结构、共混物具有更好的抗冲击性能。Brabender流变仪研究表明,CPE能促进PVC的塑化,共混物的加工性优于纯PVC。     

BA原位接枝聚合PVC的结构与性能研究

采用水相悬浮聚合法合成了PVC-BA共聚物。红外光谱和核磁共振证明:共聚产物PVC-BA具有接枝结构。凝胶渗透色谱(GPC)测试结果发现:PVC接枝聚合后分子量变大,分布变宽。采用透射电镜(TEM)研究反应前后PVC颗粒内部结构形态的变化,证明在PVC初级粒子间孔隙中BA发生了原位接枝反应。热失重分析(TG)表明:PVC-BA共聚物的热稳定性较PVC有改善。     

共聚型丙烯酸酯抗冲改性剂的合成及其对PVC的改性

采用乳液聚合法合成了核壳结构的丙烯酸酯共聚物（ACR）。借助于动态光散射粒径分析法，透射电镜，IR，DSC考察了ACR共聚物乳胶粒径，核壳结构，组成变化及玻璃化转变。发现层单体比对缺口冲击强度有较大影响，缺口冲击强度随着核层橡胶相质量的增加而明显上升。此外还考察了复合乳化剂使用的情况，并用扫描电镜观察了冲击样条断面的形貌特征。这种ACR与PVC共混后能显著提高其冲击强度。     

改性纳米碳酸钙增韧PVC研究

研究了改性纳米碳酸钙对PVC材料结构和性能的影响,主要考察了改性纳米碳酸钙及改性剂用量对PVC力学性能的影响,并对复合材料的结构进行了观察.研究表明,与ACR增韧PVC相比较,改性纳米碳酸钙在大幅度提高PVC材料缺口冲击强度的同时能保持基体的刚性.二者并用则在进一步提高PVC复合材料的缺口冲击强度的同时改善了材料的断裂伸长率;冲击试样断面显示出比较典型的韧性断裂特征,而且改性纳米碳酸钙在PVC基体中的分散良好.     

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。