ACR乳胶特性对ACR—g—VC树脂力学性能的影响

叙速了采用在ACR链上接枝氟乙烯（VC）单体达到对PVC树脂增韧改性的目的、研究结果表明：ACR的抗冲效果与ACR胶乳特性密切相关，合成PBA时B（交联剂）最佳用量为1％左右；BA／MMA最佳投料比80／20左右，ACR—g—VC抗冲强度随ACR含量增加而增加；制得的ACR—g—VC树脂性能达到Vinnolit公司同类产品H2264z树脂实测水平。     

CPE-g-VC共聚树脂结构与性能的关系

采用悬浮溶胀接枝共聚方法合成不同CPE含量的CPE - g -VC共聚树脂 ,对其加工性能和力学性能进行了研究 ,并与PVC、PVC/CPE共混物进行比较。结果表明 :接枝共聚物的加工性能优于PVC和PVC/CPE共混物 ,且其加工性能随CPE含量增加而逐渐改善 ;在CPE含量相同时 ,CPE - g -VC共聚物的冲击强度大于PVC/CPE共混物 ,冲击强度随CPE含量的增加而增强 ;当CPE含量相同时 ,CPE -g -VC共聚物的冲击强度随接枝率增加而增强 ;相近CPE含量的接枝共聚物的屈服强度大于共混物。     

氯乙烯—甲基丙烯酸环氧丙酯共聚树脂的合成及其性能

采用甲基丙烯酸环氧丙酯（EAMA）与氯乙烯（VC）共聚以改进聚氯乙烯的加工性能。研究表明，少量EAMA与VC共聚，使聚合速率大为降低；共聚树脂的分子量随转化率增加而增大，随共聚组成中EAMA含量增加而逐渐减小；共取和树脂的热稳定性和加工性能随EAMA含量增加而提高。     

EVA-VC接枝共聚树脂组成测定方法的研究

一、前言 EVA-VC接枝共聚树脂是PVC硬制品的优良抗冲改性剂之一,国外已于60年代中期开始生产,近年来还在不断研究改进。按照聚合机理推断,此种共聚树脂中应含有未发生接枝反应的游离EVA、PVC均聚物和EVA-VC接枝共聚物;各组分的含量随     

可逆加成-断裂链转移聚合制备聚氯乙烯-b-聚乙二醇-b-聚氯乙烯共聚物

合成了含黄原酸酯端基的聚乙二醇（X-PEG-X）大分子链转移剂,并以其为可逆加成-断裂链转移试剂调控氯乙烯（VC）溶液和悬浮聚合,合成聚氯乙烯-b-聚乙二醇-b-聚氯乙烯（PVC-b-PEG-b-PVC）三嵌段共聚物。X-PEG-X调控VC溶液聚合得到的共聚物的分子量随聚合时间增加而增大,分子量分布指数小于1.65。X-PEG-X具有水/油两相分配和可显著降低水/油界面张力的特性,以X-PEG-X为链转移剂和分散剂,通过自稳定悬浮聚合也可合成PVC-b-PEG-b-PVC共聚物,共聚物颗粒无皮膜结构,分子量随聚合时间增加而增大;由于VC悬浮聚合具有聚合物富相和单体富相两相聚合特性,共聚物分子量分布指数略大于溶液聚合共聚物。通过乙酸乙烯酯（VAc）扩链反应进一步证实了PVC-b-PEG-b-PVC的“活性”,并合成PVAc-b-PVC-b-PEG-b-PVC-b-PVAc共聚物。水接触角测试表明PVC-b-PEG-b-PVC的亲水性优于PVC。     

可逆加成-断裂链转移聚合制备聚氯乙烯-b-聚乙二醇-b-聚氯乙烯共聚物

合成了含黄原酸酯端基的聚乙二醇(X-PEG-X)大分子链转移剂,并以其为可逆加成-断裂链转移试剂调控氯乙烯(VC)溶液和悬浮聚合,合成聚氯乙烯-b-聚乙二醇-b-聚氯乙烯(PVC-b-PEG-b-PVC)三嵌段共聚物。X-PEG-X调控VC溶液聚合得到的共聚物的分子量随聚合时间增加而增大,分子量分布指数小于1.65。X-PEG-X具有水/油两相分配和可显著降低水/油界面张力的特性,以X-PEG-X为链转移剂和分散剂,通过自稳定悬浮聚合也可合成PVC-b-PEG-b-PVC共聚物,共聚物颗粒无皮膜结构,分子量随聚合时间增加而增大;由于VC悬浮聚合具有聚合物富相和单体富相两相聚合特性,共聚物分子量分布指数略大于溶液聚合共聚物。通过乙酸乙烯酯(VAc)扩链反应进一步证实了PVC-b-PEG-b-PVC的"活性",并合成PVAc-b-PVC-b-PEG-b-PVC-b-PVAc共聚物。水接触角测试表明PVC-b-PEG-b-PVC的亲水性优于PVC。     

ACR—g—VC接枝共聚高抗冲树脂研究进展

本文叙述了PVC树脂的增韧机理，归纳了PVC制品的增韧方式，对抗冲改性剂ACR的合成过程及结构性能表征方法进行了详速，并研究了ACR—g—VC接枝共聚树脂的制造要点，最后简要介绍了接枝共聚树脂性能的评价手段。     

甲基丙烯酸甲酯-丙烯酸乙酯乳液共聚动力学研究

为了合成适于药物包衣用的甲基丙烯酸甲酯-丙烯酸乙酯(MMA-EA)共聚物胶乳,对以非离子型乳化剂OP-10为乳化剂、过硫酸钾为引发剂的MMA-EA乳液共聚动力学进行了研究。发现初期共聚速率随着乳化剂浓度、引发剂浓度和聚合温度的增加而增大,这是由于共聚物乳胶粒子平均粒径随着乳化剂、引发剂浓度和聚合温度的增加而减小,乳胶粒子数目增加所致。通过调节乳化剂、引发剂以及反应温度可以达到合适的聚合反应速率,最终合成出转化率大于95%的MMA-EA共聚乳液。     

氯乙烯-醋酸乙烯酯-马来酸酐乳液共聚转化率和胶乳特性

以十二烷基硫酸钠(SDS)和α-丙烯基烷基酚聚氧乙烯醚(10)硫酸铵(HS-10)为复合乳化体系、偶氮二异丁脒盐酸盐(AIBA)为引发剂,采用间歇乳液聚合合成氯乙烯-醋酸乙烯酯-马来酸酐(VC-VAc-MAH)共聚物胶乳,研究了聚合温度、AIBA用量、SDS和HS-10用量及初始单体投料比对聚合转化率、胶乳稳定性和乳胶粒子粒径的影响。结果表明:MAH的加入使胶乳稳定性下降,加入HS-10虽使聚合转化率略有降低,但胶乳稳定性增加;聚合转化率随聚合温度和引发剂用量的增加而增加;当SDS用量为3%(质量分数)时,胶乳稳定,聚合转化率较大;乳胶粒子粒径随着SDS用量的增加而减小,HS-10用量对乳胶粒子粒径的影响较小;随着投料单体中VAc或MAH含量的增加,聚合转化率降低;固定投料单体组成时,共聚物中VAc和MAH含量随转化率的增加而增加。     

氯化聚乙烯/氯乙烯悬浮溶胀接枝共聚聚合温度-压力-转化率模型

根据氯乙烯(VC)在气相、水相、聚氯乙烯(PVC)富相、氯化聚乙烯(CPE)相和单体富相的分配，建立了CPE／VC悬浮溶胀接枝共聚聚合温度—压力—转化率模型。该模型可用于共聚体系VC临界转化率和临界转化率后VC转化率的预测，实现聚合终点的控制。模型和实验结果表明，随着聚合体系中CPE含量增加，VC临界转化率和一定压降时的转化率减小，这是由于VC在单位质量CPE中的溶胀量大于VC在PVC中的溶胀量所致。实验测定的不同CPE含量或压降时的VC聚合转化率与模型结果吻合较好。     

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.     

Improving mechanical properties of poly(vinyl chloride) by doping with organically functionalized reactive nanosilica

Nanosilica particles are functionalized by in situ surface‐modification with trimethyl silane and vinyl silane. Resultant reactive nanosilica (coded as RNS) contains double bonds and possesses good compatibility with vinyl chloride (VC) and polyvinyl chloride (PVC). This makes it feasible for RNS to copolymerize with VC generating RNS/PVC composites via in situ suspension polymerization. As‐prepared RNS/PVC composite resins are analyzed by means of FTIR. The tensile strength and impact strength of compression‐molded RNS/PVC composites are measured and compared with that of compression‐molded PVC composites doped with dispersible nano‐SiO₂ particles (abridged as DNS) surface‐modified with trimethyl silane alone. Moreover, the thermal stability of compression‐molded RNS/PVC and DNS/PVC composites is evaluated by thermogravimetric analysis. It has been found that RNS/PVC composites possess greatly increased impact strength and tensile strength than PVC matrix, while DNS/PVC composites possess higher impact strength than PVC matrix but almost the same tensile strength as the PVC matrix. This implies that DNS is less effective than RNS in improving the mechanical strength of PVC matrix. Particularly, RNS/PVC composites prepared by in situ suspension polymerization have much higher mechanical strength than RNS/PVC composites prepared by melt‐blending, even when their nanosilica content is only 1/10 of that of the melt‐blended ones. Besides, in situ polymerized RNS/PVC and DNS/PVC composites have better thermal stability than melt‐blended nanosilica/PVC composites. Hopefully, this strategy, may be extended to fabricating various novel high‐performance polymer‐matrix composites doped with organically functionalized nanoparticles like RNS. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

黄原酸酯调控的氯乙烯的可逆-加成断裂链转移聚合

以三种不同结构的黄原酸酯为调控剂,进行氯乙烯（VC）溶液和细乳液可逆加成-断裂链转移（RAFT）聚合,发现O-乙基黄原酸丙酸乙酯对VC聚合的调控效果良好,氯乙烯RAFT细乳液聚合速率明显大于溶液聚合,VC聚合12 h转化率大于90%,但聚氯乙烯（PVC）的分子量分布宽于溶液聚合产物。核磁共振和紫外可见吸收光谱分析证明合成的PVC具有黄原酸酯基端基结构,结构缺陷少。含黄原酸酯基PVC可进一步调控VC及醋酸乙烯酯聚合,进行扩链或得到嵌段共聚物。结合聚合动力学,说明黄原酸酯调控的氯乙烯聚合具有活性特征。     

A tough noncombustible material prepared by grafting of poly(2‐ethylhexyl acrylate) with vinyl chloride

A noncombustible tough poly(vinyl chloride) (tPVC) was prepared by suspension‐grafted copolymerization of poly(2‐ethylhexyl acrylate) (poly‐EHA; elastomer) with vinyl chloride (VC). Elastomer (poly‐EHA) was prepared by emulsion, mainly homopolymerization of 2‐ethylhexyl acrylate at a temperature of 30 ± 0.1°C in the presence of a redox system and with the advantage of dosing the monomer into two portions. Grafted‐suspension copolymerization of poly‐EHA with VC was carried out at 54 ± 0.1°C, keeping other reaction conditions only slightly modified in comparison with those for the polymerization of pure VC. An optimum content of the incorporated poly‐EHA in PVC was found to be in the range 7.5–8.5 wt %, whereas notched toughness of 85–87 kJ m^?2 was reached. Both below and above the found range of the content of poly‐EHA, the toughness decreases. A copolymer prepared by a direct‐emulsion copolymerization of 2‐EHA and VC (poly‐EHA‐co‐VC) exhibited worse mechanical properties than the copolymer prepared by two polymerization steps. On the basis of experimental results, effects of the reaction procedure on the properties of resulting material are described. In addition to good mechanical properties, tPVC also shows its noncombustibly. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2355–2362, 2002     

高抗冲ACR接枝VC共聚树脂的应用

比较了ACR接枝VC共聚树脂与CPE对PVC干混料加工性能、给水用PVC-U管材性能的影响。结果表明:①与CPE相比,ACR接枝VC共聚树脂可降低PVC干混料的平衡转矩,缩短塑化时间,节约能源消耗;②对于Φ32、Φ110给水用PVC-U管材,添加ACR接枝VC共聚树脂生产的PVC-U管材性能全部符合国家标准,且综合性能全部优于添加CPE生产的PVC-U管材。     

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     

偏氯乙烯－氯乙烯悬浮共聚树脂的研制研究

采胳悬浮共聚的方法研制了偏氯乙烯/氯乙烯（VCD/VC）共聚树脂。考察了共聚配方、分散剂种类及用量、搅拌速度及聚合温度等对VDC/VC共聚树脂的影响。     

VC／BA共混物增容PVC／HDPE共混体系的研究

采用氯乙烯—丙烯酸丁酯(VC/BA)共混物作为聚氯乙烯(PVC)/高密度聚乙烯(HDPE)共混物的增容剂,通过冲击实验、拉仲实验、动态力学分析,系统地研究了共混体系性能与其结构之间的关系。通过Brabender流变仪测定了VC/BA共混物增容PVC/HDPE共混体系的流变性能。结果表明,VC/BA共混物是PVC/HDPE共混体系的良好增容剂。在一定范围内,VC/BA共混物与HDPE对PVC有协同增韧效应。vC/BA和HDPE的加入改善了PVC的塑化和流变性能