表面活性剂增容PVC／SBR共混体系相容性研究

本文通过ＤＳＣ、振簧仪研究了聚氧化乙烯类表面活性剂作为增容剂对ＰＶＣ／ＳＢＲ共混物相容性的影响，并用扫描电镜（ＳＥＭ）观察了ＰＶＣ／ＳＢＲ共混物中橡胶分散相的形态结构和尺寸变化。结果表明，在ＰＶＣ／ＳＢＲ共混物中加入适量的表面活性剂可明显改善两相的相容性，橡胶分散相尺寸随表面活性剂用量、液体石蜡用量的变化而变化。     

氯化乙丙橡胶胶增容PVC／SBS共混体系的研究

以氯化乙丙橡胶（ＣＥＰＤＭ）为相容剂,研究了ＳＢＳ对ＰＶＣ的共混增韧改性。结果表明ＣＥＰＤＭ能明显改善ＳＢＳ与ＰＶＣ的相容性,使共混物中ＳＢＳ颗粒尺寸明显减小,分布更均匀,共混物的ｔｇ内移,常常和低温下制品冲击强度增大。当ＰＶＣ／ＳＢＳ／ＣＥＰＤＭ为８０／２０／６（质量比）时,共混物的常温缺口冲击强度为５６．３ｋＪ／ｍ＾２,低温（－２０℃）缺口冲击强度为３２．４ｋＪ／ｍ＾２。     

透明PVC／MBS合金的研究

本文对不同型号的ＰＶＣ与ＭＢＳ进行共混改性,通过冲击,应力－应变试验,动态力学分析（ＤＭＡ）、扫描电镜（ＳＥＭ）和紫外可见光谱研究了ＰＶＣ／ＭＢＳ共混体系的性能与形态结构之间的关系。结果表明,用ＭＢＳ改性ＰＶＣ既能有效地提高共混物的韧性,又能保证其具有良好的透光率。     

稳定剂及加工工艺条件对PVC／MBS光学性能的影响

本文就稳定剂和加工工艺条件对ＰＶＣ／ＭＢＳ共混物的透光率的影响进行了探讨，发现稳定剂种类、用量、加工温度和时间对ＰＶＣ／ＭＢＳ共混物制品的光学性能有较大的影响。在用量相同的情况下，ＴＭ－１８１ＦＳ的持久热稳定效果要比京锡８８３１好，而耐初期着色性则相差不大，ＴＭ－１８１ＦＳ的用量以１．５～２．５份为宜。环氧大豆油与有机锡组成的复合稳定体系具有协同性，稳定效果较好。随着塑化时间的延长，ＰＶＣ／ＭＢＳ的透光率下降。混炼时间较短时，随温度的升高，共混物的透光率变化不大；当混炼时间较长时，加工温度越高，ＰＶＣ／ＭＢＳ共混物的透光率越低     

马来酸酐接枝SBS增容PVC／SBS的研究

马来酸酐接枝苯乙烯－丁二烯＝苯乙嵌段共聚物（ＳＢＳ）用ＭＳＢＳ代表,以它为增容剂,研究了ＳＢＳ对聚氯乙烯（ＰＶＣ０的共混增韧改性。结果表明：ＭＳＢＳ能明显改善ＳＢＳ与ＰＶＣ的相容必 分散相ＳＢＳ相区尺寸明显减小,分布更均匀,共混物的玻璃化转变温度内移,常温和低温下缺口冲击强度增大。当ＰＶＣ／ＳＢＳ／ＭＳＢＳ为７５：２５：４时,共混物的常温缺口冲击强度为５８．３ｋＪ／ｍ＾２,低温（－２０℃）缺口冲击     

粉末改性SBR对PVC的增韧作用

研究了粉末改性ＳＢＲ对ＰＶＣ的增韧作用。用ＴＥＭ、ＳＥＭ和ＤＳＣ对粉末改性ＳＢＲ与ＰＶＣ共混物进行了分析。发现粉末改性ＳＢＲ对ＰＶＣ有显著的增韧效果。当粉末改性ＳＢＲ用量由５份增加到１０份，共混物的冲击强度由１０～２０ｋＪ／ｍ２突然升高到８５～１００ｋＪ／ｍ２。这种突变是由改性ＳＢＲ在ＰＶＣ基体中的相形态由分散相转变为网状结构，导致共混物由脆性断裂过渡到韧性断裂造成的。ＤＳＣ分析显示改性ＳＢＲ与ＰＶＣ部分相容。     

粉末生SBR对PVC的增韧作用

研究了粉末改性ＳＢＲ对ＰＶＣ的增韧作用，用ＴＥＭ、ＳＥＭ和ＤＳＣ对粉末改性ＳＢＲ与ＰＶＣ共混物进行了分析，发现粉末改性ＳＢＲ对ＰＶＣ有显著的增韧效果。当粉末改性ＳＢＲ用量由５份增加到１０份，共混物的冲击强度由１０－２０ｋＪ／ｍ＾２突然升高到８５－１００ｋＪ／ｍ＾２。这种突变是由改性ＳＢＲ在ＰＶＣ基体中的相形态由分散相转变为网状结构，导致共混物由脆性断裂过渡到韧性断裂造成的。ＤＳＣ分析显示改性ＳＢＲ     

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。     

CPE对PVC／SBR共混体系增容作用的研究

通过微观冲击试验、动态力学分析（ＤＭＡ）、扫描电镜（ＳＥＭ）和透射电镜（ＴＥＭ）观察，研究了氯化聚乙烯（ＣＰＥ）增容的ＰＶＣ／丁苯橡胶（ＳＢＲ）共混物的性能与形态结构之间的关系。试验结果表明ＣＰＥ对ＰＶＣ／ＳＢＲ共混体系有良好的增容作用。     

PVC／SBR热塑性弹性体的研制

以ＡＢＳ、氯丁橡胶（ＣＲ）、马来酸酐（ＭＡ）接枝ＳＢＲ（ＳＢＲ－ＭＡ）作增容剂对ＰＶＣ／ＳＢＲ的共混比、增容剂、增塑剂用量做了优化选择。同时对动态硫化ＰＶＣ／ＳＢＲ的硫化体系、硫化工艺条件进行了探讨,并比较了动态硫化对共混体性能的影响。结果表明：ＰＶＣ／ＳＢＲ为８０／２０,增容剂ＡＢＳ／ＳＢＲ－ＭＡ为５／５时,选用半有效硫化体系,１６５℃下动态硫化６ｍｉｎ,共混物综合性能最佳     

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.     

Processing morphology of PVC/MBS blend

MBS resin, an impact modifier for PVC, plays an important role in PVC processing, the details of which, however, are not well understood. The use of a temperature programmable Brabender Plasticorder and new microscopic techniques have revealed that MBS inhibits the comminution of PVC grain in the initial stage of processing, and PVC breakdown occurs after the MBS melts. Dynamic melting of MBS is observed as a Brabender torque peak. These characteristics of PVC/MBS blends are quite different from those of PVC/processing aid blends. Processing features of PVC/MBS blends are reported and compared with those of PVC/processing aid blends.     

HIPS对不同PVC体系的改性研究

研究了刚性有机粒了ＨＩＰＳ对不同改性ＰＶＣ体系力学性能的影响。结果表明，对于改性ＰＶＣ／ＰＥ－Ｃ基体，添加少量的ＨＩＰＳ后，共混体系塑化行为改善，缺口 冲击强度明显的提高，拉伸强度下降不大；而对于改性ＰＶＣ和改性ＰＶＣ／ＭＢＳ基体，共混体系的力学性能没有提高，且有负面影响。     

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     

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。     

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。     

胶乳型互穿网络制备高性能MBS树脂

采用胶乳型互穿网络制备出了性能优异的MBS树脂,产品在亚微观形态上具有完美的核一壳结构,并与PVC具有极好的相容性,比较于传动方法制备的MBS树脂,制品的冲击性能和光学性能得到明显改善。     

Photooxidative degradation of carboxylated poly(vinyl chloride)

Thin films of poly(vinyl chloride), PVC, and carboxylated poly(vinyl chloride), C-PVC, containing 1.8% of carboxyl groups were exposed to high energy ultraviolet radiation (λ = 254 nm) in laboratory conditions. The photochemical reactions in irradiated samples were studied by FTIR and UV–Vis spectroscopy, gel permeation chromatography and gravimetric estimation of insoluble gel. It was found that photodegradation and photocrosslinking in C-PVC is accelerated, whereas photodehydrochlorination is retarded comparing to these processes in PVC. Photooxidation investigated on the base of reaction leading to formation of hydroxyl groups is also more efficient in modified PVC. However, the total amount of carbonyl groups is much lower in UV-irradiated C-PVC than that in PVC. It indicates that competitive reactions (destruction of carboxyl groups and formation of new carbonyls) occur simultaneously in C-PVC chains. The influence of carbonyl groups on photochemical processes can be explained by an efficient Norrish I and II reactions as well as by energy transfer from absorbing species to weak chemical bonds.     

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.