Preparation and characterization of thermoplastic elastomer of poly(vinyl chloride) and chlorinated waste rubber

In order to develop applications for the abundant waste rubber powder, chlorinated waste rubber (Cl-WR) was prepared by a water based chlorination method using chlorine as chlorinating agent. In this paper, Cl-WR was used as an elastic filler and blended with poly(vinyl chloride) (PVC) matrix to develop a new thermoplastic elastomer PVC/Cl-WR. The mechanical properties, hydrophilicity, swelling resistance, morphology and thermal properties of PVC/Cl-WR were characterized and compared with those of PVC/waste rubber powder (PVC/WR) blends. The results indicated that the mechanical properties, hydrophilicity, swelling resistance and thermal properties of the PVC/Cl-WR blends showed noticeable improvements over PVC/WR blends due to the improved polarity of Cl-WR. Also, the excellent miscibility and compatibility of Cl-WR with PVC was demonstrated by scanning electron microscope (SEM) images of the resulting blends.     

Nanotubes as polymer composite reinforcing additive materials – A comparative study

Nitrogen-doped bamboo-shaped carbon nanotubes (N-BCNTs) and their non-doped conventional counterparts, multiwalled carbon nanotubes (MWCNTs) were compared as polymer reinforcing additives in polyvinyl chloride (PVC) matrix. The nanotubes were synthetized by catalytic chemical vapor deposition (CCVD) method. The purity of both nanotubes was measured by thermogravimetric analysis (TGA) and found to be >91%. Further analysis on the morphology and size of the carbon nanotubes (CNTs) were performed by transmission electron microscopy (TEM). The PVC powder was impregnated with CNTs in ethanol by using tip ultrasonicator. The dispersion media was evaporated, and the CNT/PVC powder was used to produce polymer fibers. The orientation of carbon nanotubes in the PVC matrix was characterized by scanning electron microscopy (SEM), and the presence of nanotubes were confirmed in case of all PVC samples. It can be observed on the SEM images that the nanotubes are fully covered with PVC. The tensile strength of the nanotube containing samples was tested and the N-BCNT/PVC composite was found to be better in this sense, thanks to the extraordinary structure of the nanotube. In case of the N-BCNT/PVC composite the measured young modulus was 39.7% higher, while the elongation at brake decreased by 33.6% compare to the MWCNT/PVC composite. These significant differences in the mechanical properties of the composites can be explained with the stronger interaction between N-BCNTs and PVC.     

聚氯乙烯表面共价键合肝素及抗凝血性的研究

采用Ar等离子体引发聚乙二醇(PEG)在聚氯乙烯(PVC)表面固定化,进一步对固定PEG后的PVC进行肝素化处理,以改善PVC材料的抗凝血性能。探讨了PEG浓度对Ar等离子体固定化反应效果的影响。通过X射线光电子能谱(XPS)、衰减全反射红外光谱(ATR-FTIR)、扫描电镜(SEM)和接触角测定研究了固定PEG前后PVC的表面性能和表面形貌的变化。XPS分析证实肝素已成功地共价键合于PVC表面。采用体外凝血时间测定和血小板粘附实验对材料的抗凝血性能进行评价,结果表明,被修饰PVC材料的抗凝血性能显著提高。     

聚氯乙烯-丙烯酸丁酯接枝共聚物的结构表征

以通用聚氯乙烯(PVC)和脱氯化氢PVC树脂为基体,采用悬浮溶胀接枝共聚法合成聚氯乙烯-丙烯酸丁酯接枝共聚物,对脱氯化氢PVC和接枝共聚物的结构进行了表征.结果表明,以碱液为介质加热PVC能脱除少量氯化氢,得到以链节数为2,3,4的共轭双键为主的不饱和结构,而树脂的分子量变化不大;在相同接枝反应条件下,采用脱氯化氢PVC与丙烯酸丁酯接枝共聚可以提高接枝率和接枝效率;PVC接枝共聚物的特性粘度随接枝率增加而增加,其重均分子量和分子量分布指数均大于接枝所用的PVC树脂.     

Influence of plasticizer content on the transition of electromechanical behavior of PVC gel actuator

The actuation performance of plasticized poly(vinyl chloride) (PVC) gel actuators in an electric field depends on their chemical composition and electrical and mechanical properties. The influence of plasticizer (dibutyl adipate) content on electromechanical behavior of PVC gels was investigated by impedance spectroscopy and space charge measurement. By plasticizing the PVC, the dielectric constant and space charge density of PVC gel were drastically increased at 1:2 w/w ratio of PVC to plasticizer. To apply the results obtained from the impedance spectroscopy and space charge measurement, electrostatic adhesive forces generated between the PVC gel and the anode were measured. The electrostatic adhesive force at the anode was also dramatically increased at the same plasticizer content. All of the results indicated a transition of electromechanical behavior of PVC gel in the electric field, which was considered to originate from the orientation of polarized plasticizer molecules and dipole rotation of PVC chains. By using the electrostatic adhesive force of PVC gel derived from the electromechanical transition, a new electroactive actuator can be developed for novel applications.     

力化学降解对聚氯乙烯加工流变行为的影响

采用Brabender塑化仪和毛细管流变仪研究了经力化学降解制得的聚氯乙烯(PVC)的加工流变行为。结果表明,降解的PVC塑化时间比未降解的PVC明显缩短,塑化速度和熔化效率也明显加快,熔体粘度及玻璃比温度降低。     

Manufacturing homogenous PVC/graphene nanocomposites using a novel dispersion agent

The goal of the study was to prepare a graphene (GN) dispersion in a poly (vinyl chloride) (PVC) solution with enhanced stability of the nanofiller thanks to the application of curcuma extract (CE). The stable dispersion was used to obtain PVC/GN nanocomposites with more homogeneous graphene by the solvent evaporation method. The CE effectiveness was compared with two commercially available dispersants in the form of oleic acid (OA) and polysorbate 80 (P80).The chemical composition of the CE was examined by Fourier-transform infrared spectroscopy. The dispersion stability was tested by the multiple light scattering method (Turbiscan Lab) and evaluated visually over a period of 40 days. The homogeneity of the filler's dispersion in the PVC matrix was evaluated by scanning electron microscopy and Raman spectroscopy.The application of the dispersing agents led to improved stability of the graphene dispersion in PVC solution. CE was the agent that most effectively improved the homogeneity of graphene dispersion, both in dispersions in a PVC solution and in PVC/GN nanocomposite films.     

强紫外光作用下PVC/增韧剂体系结构与性能的演变

通过UV, FTIR, DSC及力学性能和色差的测试分析, 实时追踪了在紫外光老化过程中, 聚氯乙烯/氯化聚乙烯(PVC/CPE), 聚氯乙烯/丙烯酸酯类共聚物(PVC/ACR)及聚氯乙烯/丙烯腈-丁二烯苯乙烯共聚物(PVC/ABS)体系的微观结构和宏观性能的演变过程. 结果表明, 在光老化过程中, ACR和CPE对PVC脱HCl生成共轭双键反应、氧化降解反应、交联反应及玻璃化转变温度(T_g)的变化等均有抑制作用, 而ABS则对这些反应起促进作用. 在宏观上表现为ACR和CPE的加入能提高体系的色泽稳定性, 体系的力学性能保持率较高. 而ABS的作用相反.     

聚氯乙烯微塑料对典型单羟基菲的吸附机制

为丰富微塑料与有机污染物间的相互作用机制相关数据,以3-羟基菲(3-OHP, C₁₄H₁₀O)为菲单羟基衍生物代表污染物,聚氯乙烯(PVC)微塑料为研究对象,研究了PVC微塑料在水环境中对3-OHP的吸附行为,并就相关吸附机制进行了深入探讨。该研究借助扫描电镜(SEM)、X射线衍射仪(XRD)、傅里叶红外光谱(FT-IR)等仪器对PVC微塑料进行表征,利用紫外分光光度计得出目标污染物的紫外吸收光谱标准曲线,标准曲线拟合相关系数(R²)>0.99。为保证紫外吸收光谱的准确性,污染物浓度梯度设置为吸光度(Abs)大于0.438,之后根据标准曲线方程计算其浓度,结合相关吸附模型(吸附动力学、吸附等温线和吸附热力学)并配合密度泛函理论(density functional theory, DFT)探讨了在水环境中PVC微塑料对3-OHP的吸附机制。结果如下:(1)吸附动力学实验结果显示伪二级动力学模型拟合程度最好,吸附动力学拟合系数R²=0.998。因此,PVC吸附3-OHP可能是以表面吸附和外液膜扩散的吸附方式,吸附发生24 h后的平衡吸附量为36.866 μg/g; (2)吸附等温线实验表明Langmuir和Freundlich等温线模型拟合度较高,吸附等温线拟合系数R ²分别为0.956和0.907,更加适合描述PVC对3-OHP的吸附过程,吸附模式主要为单层吸附,也存在小部分多层吸附,PVC对3-OHP的最大吸附量为408 μg/g; (3)吸附热力学结果显示PVC微塑料对3-OHP的吸附效率随着温度升高而降低,这表明PVC对3-OHP的吸附为自发、放热的吸附反应;(4)盐度实验结果表明,盐度对3-OHP在PVC上的吸附效率影响不大;(5)DFT理论计算结果表明PVC对3-OHP结合能相对较低,因此推测PVC对3-OHP的主要吸附机制可能是疏水作用,还可能存在弱氢键作用、卤素键作用以及π-π共轭作用。研究揭示了PVC微塑料与有机物相互作用方式,明确了PVC微塑料对3-OHP的吸附模式,探讨了PVC微塑料对3-OHP的相互作用机制,有助于更好地了解PVC微塑料在水溶液中的环境行为。该研究为科学评价微塑料的环境影响提供数据参考,并进一步补充了微塑料的毒理学机制数据。     

聚氯乙烯燃烧特性及HCl的生成机理

采用热重法对聚氯乙烯（ＰＶＣ）的燃烧过程进行了研究,探讨阳聚氯乙烯燃烧科技司,并由它们的微分热重曲线计算出的反应动力学参数及影响反应常数的因素进行了研究。同时,考察了恒速升温和快速升温过程ＨＣＩ的生成特性。结果表明,ＰＶＣ的燃烧机理是由三个过程决定的,可用三个一级反应表示。ＰＶＣ的燃烧过程的第一阶段为脱氯阶段。第二阶段的活化能和指前因子明显低于第一和一阶段。此阶段为挥发分释放阶段。升温速率的增加导     

Determination of branching in polyethylene and poly(vinyl chloride) using pyrolysis gas chromatography

A series of polyethylenes (PE), reduced poly(vinyl chlorides), and precursor poly(vinyl chloride) (PVC) systems were studied by pyrolysis–gas chromatography (PGC) and by pyrolysis–hydrogenation–gas chromatography (PHGC). The branch content of these polymers has been interpreted on the basis of previously established literature information. Low-density PE (LDPE) was found to contain a significant number of ethyl branches. The pyrolysis results on an LAH-reduced PVC series gave significant insight on PVC microstructure. It was determined that the short-chain branches in PVC are mainly one carbon long. Some ethyl side chains and virtually no butyl branches were found in this experimental PVC series. The effect of chain branching on the pyrolysis of PVC is to increase fragmentation. The benzene/toluene ratio, along with relative amounts of benzene and naphthalene formed, may be used to indicate the relative degree of branching in this system. The application of PGC and PHGC have thus been shown to successfully extend analytical work on PE and PVC and to provide microstructural information.     

Morphology and fracture behavior of toughening‐modified poly(vinyl chloride)/organophilic montmorillonite composites

Toughening‐modified poly(vinyl chloride) (PVC)/organophilic montmorillonite (OMMT) composites with an impact‐modifier resin (Blendex 338) were prepared by melt intercalation, and their microstructures were investigated with wide‐angle X‐ray diffraction, transmission electron microscopy, and scanning electron microscopy. The mechanical properties of the PVC composites were examined in terms of the content of Blendex and OMMT, and the fracture toughness was analyzed with a modified essential work of fracture model. Intercalated structures were found in the PVC/OMMT composites with or without Blendex. Either Blendex or OMMT could improve the elongation at break and notched impact strength of PVC at proper contents. With the addition of 30 phr or more of Blendex, supertough behavior was observed for PVC/Blendex blends, and their notched impact strength was increased more than 3319% compared with that of pristine PVC. Furthermore, the addition of OMMT greatly improved both the toughness and strength of PVC/Blendex blends, and the toughening effect of OMMT on PVC/Blendex blends was much larger than that on pristine PVC. Blendex and OMMT synergistically improved the mechanical properties of PVC. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 286–295, 2004     

Nitroxide mediated living radical polymerization of styrene onto poly (vinyl chloride)

Nitroxide‐mediated ‘living’ free radical polymerisation (LREP) was employed for the first time to prepare graft copolymer by having arylated poly (vinyl chloride) (PVC‐Ph) as a backbone and polystyrene (PS) as branches. The graft copolymerization of styrene was initiated by arylated PVC carrying 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO) groups as a macroinitiator. Thus, the arylated PVC was prepared in the mild conditions and these reaction conditions could overcome the problem of gelation and crosslinking in polymers. Then, 1‐hydroxy TEMPO was synthesized by the reduction of TEMPO with sodium ascorbate. This functional nitroxyl compound was coupled with brominated arylated PVC (PVC‐Ph‐Br). The resulting macro‐initiator (PVC‐Ph‐TEMPO) for ‘living’ free radical polymerization was then heated in the presence of styrene to form graft copolymer. DSC, GPC, ¹HNMR, and FT‐IR spectroscopy were employed to investigate the structure of the polymers. Copyright © 2007 John Wiley & Sons, Ltd.     

P(BA-EHA)/PVC复合胶乳的制备及表征

采用乳液聚合法合成了丙烯酸丁酯与丙烯酸 2 乙基己酯交联共聚物 [P(BA EHA) ]乳液 ,以P(BA EHA)乳液为种子通过与氯乙烯 (VC)聚合制备了P(BA EHA) PVC复合胶乳 .考察了P(BA EHA)乳液用量对复合胶乳粒径及其材料力学性能的影响 ,借助透射电镜 (TEM)、扫描电镜 (SEM)和动态力学分析 (DMA)等手段对复合胶乳粒子及其所制材料的形态结构进行了表征 .DMA研究结果表明 ,橡胶相P(BA EHA)与基体PVC间相容性得到了良好改善 .随着P(BA EHA)含量的增加 ,低温区材料的力学损耗峰较纯聚氯乙烯增强 ,且峰位逐渐向高温区移动 .TEM照片显示 ,复合胶乳粒子具有清晰的核壳结构 ;P(BA EHA)非常均匀地分散在PVC中 ,两相界面模糊 .由SEM照片可见 ,材料缺口断面表现为很好的韧性断裂 .含 4 2 %P(BA EHA)材料的缺口抗冲强度是PVC的 11倍 ,断裂伸长率较PVC提高近两倍 .     

Fabrication and characterization of polyvinyl chloride/poly(styrene-co-maleic anhydride) intercalated functional nanobifiller-based composite paper

The resin infiltration technique was used for impregnation of graphene oxide (GO) and graphene oxide-functional carbon nanotube (GO-ox-CNT) with polyvinyl chloride (PVC) and poly(styrene-co-maleic anhydride) (PSMA) blend. Two series of buckypapers were prepared with GO and GO-ox-CNT content. The morphology of PVC/PSMA/GO composite paper was porous, while PVC/PSMA/GO-ox-CNT revealed exclusive morphology with GO islands and intercalated ox-CNT networks covered with PVC/PSMA. T_max of PVC/PSMA/GO-ox-CNT 0.1 was 571°C, whereas PVC/PSMA/GO 0.1 had a lower value (559°C). T_g of PVC/PSMA/GO-ox-CNT 0.1 was also higher (290°C). Cone calorimetric results showed a decrease in PHRR from 499 (blend) to 186 kW/m² with 0.3 g GO-ox-CNT.     

One-pot polyvinyl chloride preparation utilizing polyacrylate latex with tertiary amine groups for improved thermal stability,toughness, and reduced reactor scaling

In this paper, crosslinked polyacrylate latex with tertiary amine groups (ACLN) and base latex without tertiary amine groups (ACL) were prepared by emulsion polymerization using butyl acrylate as the monomer and 1,4-butanediol dimethacrylate as the crosslinker. Composite resins of polyvinyl chloride (PVC), ACL/PVC and ACLN/PVC, were prepared by suspension polymerization of vinyl chloride in a 20 L high-pressure reactor by adding ACL and ACLN as modifiers. The inner pressure of the reactor and initiator concentration as a function of reaction time during suspension polymerization were studied. Morphology of resin particles, processing properties, thermal stability and mechanical properties of ACL/PVC and ACLN/PVC products were investigated. A commercial PVC product named PVC-SG5 was used as the control sample for comparison. It was found that compared with typical PVC-SG5 preparation, ACL/PVC fabrication took less time while initiator concentrations needed to be increased to 2400 ppm in ACLN/PVC preparation in order to complete the polymerization within the same time. Reactor scaling occurred during ACL/PVC preparation, but could be avoided in ACLN/PVC preparation owing to the hydrophilicity of ACLN. The morphology of ACL/PVC and ACLN/PVC particles was smooth microspheres and mosaic particle shapes, respectively, the diameter of which were all smaller than PVC-SG5 particles. The covalent-bonding existing in ACL/PVC and ACLN/PVC, and ionic-bond formation of quaternary ammonium in ACLN/PVC composite resins, between tertiary amine groups in ACLN and chlorine atoms in PVC, contributed to the dramatic increase in thermal stability. ACLN/PVC exhibited the shortest plasticizing time and the longest elongation at break, followed by ACL/PVC. The toughness of both ACL/PVC and ACLN/PVC were greatly enhanced without affecting the tensile strength and softening temperature of the resin. Thus, three issues, namely, low thermal stability, low toughness and reactor scaling during polymerization of PVC have been comprehensively solved by introducing ACLN to PVC through a one-pot method.     

Thermal degradation of poly(vinyl chloride)/poly(ethylene oxide) blends: Thermogravimetric analysis

Thermal stability of poly(vinyl chloride)/poly(ethylene oxide) (PVC/PEO) blends has been investigated by thermogravimetric analysis (TGA) in dynamic and isothermal heating regime. PVC/PEO blends were prepared by hot-melt extrusion (HME). According to TG analysis, PEO decomposes in one stage, while PVC and PVC/PEO blends in two degradation stages. In order to evaluate the effect of PEO content on the thermal stability of PVC/PEO blends, different criteria were used. It was found that thermal stability of PVC/PEO blends depends on the blend composition. The interactions of blends components with their degradation products were confirmed. By using multiple heating rate kinetics the activation energies of the PVC/PEO blends thermal degradation were calculated by isoconversional integral Flynn–Wall–Ozawa and differential Friedman method. According to dependence of activation energy on degree of conversion the complexity of degradation processes was determined.     

丙烯酰胺在以N,N-二乙基二硫代氨基甲酰基修饰聚氯乙烯上的紫外光非均相接枝聚合

丙烯酰胺在以Ｎ，Ｎ 二乙基二硫代氨基甲酰基修饰聚氯乙烯上的紫外光非均相接枝聚合杨文君王永祥管建均（青岛化工学院橡塑工程研究所青岛２６６０４２）沈家骢（吉林大学化学系长春１３００２３）关键词聚氯乙烯，聚丙烯酰胺，功能高分子，接枝聚合反应，铜试剂以聚氯...     

Optimization of the thickness of a conducting polymer, polyaniline, deposited on the surface of poly(vinyl chloride) membranes: a new way to improve their potentiometric response

Repeated depositions of polyaniline (PANI) have been used to control the thickness of the polymeric film deposited on poly(vinyl chloride) (PVC) membrane surface. The oxidation of aniline was carried out in a dispersion mode, i.e. in the presence of poly(N-vinylpyrrolidone) (PVP). Two kinds of PVC were used for this purpose: a non-plasticized PVC for the study of PANI deposition and PVC, plasticized with nitrophenyl octyl ether (NPOE), as a prototype of a liquid membrane electrode. The results of UV-visible and FTIR spectroscopies and electron microscopy showed that (1) the film thickness increased by about equal increments of ∼40 nm after each polymerization, and (2) the interface with PVC was constituted by PANI film and adhering PANI-PVP colloidal particles.The various thicknesses of the deposited PANI films affected the potentiometric response of the NPOE/PVC membrane with and without an anion-exchanger. The potentiometric anionic response was observed with a minimal thickness of PANI film on the blank NPOE/PVC membrane. Sensitivity of the PANI film to pH occurred only with a blank NPOE/PVC membrane coated with a thick polymeric film, while it was strongly suppressed by the presence of a lipophilic anion-exchanger, tridodecylmethylammonium chloride (TDDMACl), in the membrane, regardless of the thickness of the polymer film. The thickness of the PANI film did not affect the anionic selectivity pattern of TDDMACl-based membranes to any great extent, but its presence improved and stabilized their potentiometric characteristics (sensitivity, linear-response range).     

Plasticizer for poly(vinyl chloride) from cardanol as a renewable resource material

The present work is aimed to the preliminary analysis of the applicability of cardanol derivatives as renewable plasticizers for soft PVC. Two different plasticizers were studied, obtained by esterification of the cardanol hydroxyl group (cardanol acetate) and further epoxidation of the side chain double bonds (epoxidated cardanol acetate). Differential Scanning Calorimetry (DSC) was used to study the miscibility between PVC and cardanol derived plasticizers. The miscibility was correlated to the chemical structure of plasticizer by means of the Hansen solubility parameter analysis. Results obtained indicated that esterification of cardanol yields a partial miscibility with PVC, whereas esterification and subsequent epoxidation yield a complete miscibility with PVC. Therefore cardanol acetate, obtained by solvent-free esterification of cardanol, was used as a secondary plasticizer of PVC. Mechanical and rheological analysis showed that the cardanol acetate can partially replace DEHP in PVC formulation.