PVC/黏土纳米复合材料研究进展

文章简要概述了黏土的有机改性机理,聚氯乙烯/黏土纳米复合材料的特性及其制备方法、结构与表征方面的研究进展。对熔融插层共混法、溶液插层共混法、原位聚合法和插层聚合法进行了介绍和比较,对聚氯乙烯/黏土纳米复合材料的重点研究领域和发展趋势提出了具有前瞻性的预测。     

Study on the Thermal Stability and Stabilization Mechanism of a Novel Thermal Stabilizer for Rigid Poly (Vinyl Chloride)

A novel thermal stabilizer for rigid poly (vinyl chloride) has been examined. Its high stabilizing efficiency is detected by the extent of discoloration and the mass loss rate of the degraded samples when compared with some of reference stabilizers. A higher stabilizing efficiency is produced as the novel thermal stabilizer is mixed with different co-stabilizers. The study results for thermo oxidative stability of the degraded samples with novel thermal stabilizer have shown that the novel thermal stabilizer can prevent or delay the thermal oxidative degradation of PVC. A probable stabilization mechanism for the novel thermal stabilizer has been proposed.     

Thermal Decomposition of Polymer Mixtures Containing Poly(vinyl chloride)

Thermal decomposition of a series of 1 : 1 mixtures of typical polymer waste materials [polyethylene (PE), poly(propylene) (PP), polystyrene (PS), polyacrylonitrile (PAN), polyisoprene, poly(methyl methacrylate) (PMMA), polyamide‐6 (PA‐6), polyamide‐12 (PA‐12), polyamide‐6,6 (PA‐6,6), and poly(1,4‐phenylene terephthalamide) (Kevlar)] with poly(vinyl chloride) (PVC) was examined using thermal analysis and analytical pyrolysis techniques. It was found that the presence of polyamides and PAN promotes the dehydrochlorination of PVC, but PVC has no effect on the main decomposition temperature of polyamides. The hydrogen chloride evolution from PVC is not altered when other vinyl polymers or polyolefins are present. The thermal degradation of PAN is retarded significantly, whereas that of the other vinyl polymers is shifted to a slightly higher temperature in the presence of PVC. Among the pyrolysis products of PAN‐PVC mixture methyl chloride was found in comparable amount to the other gaseous products at 500°C pyrolysis temperature.     

Topokinetics of the Polyene Formation in Poly(Vinyl Chloride) Films during Treatment with Nonoxidative Plasma

Abstract

Changes of the physical and chemical structure of a polymer solid during plasma treatment are mainly caused by two processes: the collision of ions, electrons and other particles with the polymer surface and the ultraviolet irradiation emitted by the plasma gas and absorbed by the polymer. The former process is limited to a very thin surface layer (only a few nanometers thick,¹ whereas the latter usually leads to a significant depth profile (up to 10 μm^1,2 or even more),³ depending on the kind of the plasma and the polymer investigated.     

氯醚树脂的制备及其在涂料中的应用研究进展

综述了氯醚树脂的结构和性能、合成工艺、改性方法及其在涂料中的应用研究进展,阐述了以悬浮聚合和乳液聚合制备氯醚树脂的一些方法,其中乳液聚合法既可以采用水溶性热引发剂体系也可采用氧化 -还原引发体系。目前,对溶剂型 /水性氯醚树脂的改性方法主要以丙烯酸树脂、环氧树脂及纳米二氧化硅和纳米二氧化钛等为主,改性后的氯醚树脂的性能显著提高,这拓宽了氯醚树脂的应用范围,目前主要的应用方向为防腐涂料、防污涂料、防火涂料乃至导电涂料等领域。     

硬聚氯乙烯低发泡挤出成型研究

采用自由发泡挤出的方法研究了硬聚氯乙烯低发泡挤出成型的配方设计和工艺条件控制。讨论了稳定剂品种，改性剂品种和发泡剂用量对制品密度，泡孔结构以及外观表面的影响。还揭示了口模温度和螺杆转速与制品密度的关系。     

Novel Strategy for Anhydride-Functionalization of Poly(Vinyl Chloride): Synthesis and Characterization

A new strategy for anhydride-functionalization of poly(vinyl chloride) is suggested. First, some chlorine groups of poly(vinyl chloride) were converted to phenylamine-oxy groups by a nucleophilic substitution reaction in the presence of a solvent composed of 4-aminophenol, K₂CO₃, and dry N,N-dimethylformamide at room temperature, to avoid cross-linking. The phenylamine-functionalized poly(vinyl chloride) was further reacted with maleic and 1,2,4-benzenetricarboxylic acid anhydrides. The chemical structures of all samples as representatives were characterized by Fourier transform infrared and nuclear magnetic resonance spectroscopies. The chemical compositions of the synthesized anhydride-functionalized poly(vinyl chloride) were investigated by elemental analysis, and their thermal behaviors were characterized by means of differential scanning calorimetry and thermogravimetric analyzer.     

The Effect of Adding Lignin to Poly(Dimethyl Siloxane)—Poly(Vinyl Chloride) Blends

A new adhesive sealant with improved mechanical properties has been prepared by blending a sealant based on poly(dimethyl siloxane)-(PDS) with poly(vinyl chloride)-(PVC) and Kraft lignin (L). During this study, California redwood was used as substrate. Two commercial primers were also used to examine their effects on the adhesion of joints. By adding a small amount of L, the modulus of the sealant based on PDS + 10% PVC is improved. The application of primers to the wood substrate has significantly improved the adhesion of PDS, PDS + 10% PVC and PDS + 10% PVC + L polyblends. Improvement in adhesion increased the stress-strain values of the joints. Statistical inference of the experimental results are also discussed.     

Chemical Modification of Poly(Vinyl Chloride) with Ethylene Glycol and its Application in Ion-Chromatography

ABSTRACT

Poly(vinyl chloride) (PVC) has been chemically modified through crosslinking with different molar ratios of sodium ethylene glycoxide in ethylene glycol. The crosslinked PVC was used for coating of silica gel 60 particles and the obtained products were impregnated with tetramethylammonium hydroxide (TMAH). The crosslinking reaction as well as the insertion of TMAH were followed up and quantitatively determined with the aid of FT-IR spectroscopic and elemental analyses. The obtained materials were roughly tested for ion chromatographic separation of different ions. Retention time ( t _R) was determined for lithium, magnesium, strontium, and calcium cations whereas chloride, nitrate, and sulfate were selected as representatives for anions.     

异山梨醇基增塑剂的制备及其增塑PVC的性能

通过异山梨醇和壬酸合成一种新型生物基增塑剂—异山梨醇二正壬酸酯(SDN)来改性聚氯乙烯(PVC)树脂.研究了绿色增塑剂的增塑作用及对共混物性能的影响.SDN特有的分子结构增大了分子链间的距离,增加了聚合物的自由体积,使共混物塑性得到明显的改善.研究表明,随着SDN增塑剂添加量的增加,材料韧性增强,增塑剂的引入降低了共混...     

Hollow Fiber Ultrafiltration Membranes from Poly(Vinyl Chloride): Preparation,Morphologies, and Properties

Hollow fiber poly(vinyl chloride) membranes were prepared by using the dry/wet spinning method. Cross-section, internal, and external surfaces of the hollow fibers structure were studied by SEM. The pore size and pore size distribution of the hollow fibers were measured by a PMI capillary flow porometer. UF experiments of pure water and aqueous solution of PVP K-90 were carried out. The effect of the PVC concentration on the hollow fibers mechanical properties was also investigated. It was found that the PVC fibers cross-sectional structure was affected by the polymer concentration in the dope solution. In particular, reduction of macrovoids size was observed when increasing PVC concentration from 15 to 19 wt%. The pore size distribution of the PVC hollow fibers was controlled by adjusting the PVC concentration. Indeed, an increase of PVC concentration up to 19 wt% leads to fibers with sharp pore size distribution (the 99% of pores is about 0.15 µm).The pure water permeation flux decreased from 162 to 128 (l/m² · h · bar), while the solute separation performance increased from 82 to 97.5%, when increasing the PVC concentration. The elongation at break, the tensile strength, and the Young's modulus of the PVC hollow fibers were improved with PVC concentration in dope solution.     

Thermal degradation behavior of poly(vinyl chloride) in the presence of poly(glycidyl methacrylate)

The thermal degradation behavior of poly(vinyl chloride) (PVC) in presence of poly(glycidyl methacrylate) (PGMA) has been studied using continuous potentiometric determination of the evolved HCl gas from the degradation process from one hand and by evaluating the extent of discoloration of the degraded samples from the other. The efficiency of blending PGMA with dibasic lead carbonate (DBLC) conventional thermal stabilizer has also been investigated. A probable radical mechanism for the effect of PGMA on the thermal stabilization of PVC has been suggested based on data reported by FTIR and elemental analyses. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

HBP/PVC的流变行为

研究了不饱和超支化聚(酰胺－酯)(HBP)／聚氯乙烯(PVC)的流变行为和玻璃化温度的变化。讨论了剪切应力和剪切速度对HBP／PVC熔体表观粘度的影响。结果表明,在研究的HBP添加量范围内,HBP／PVC的熔体表观粘度大于PVC的。当PVC中加入HBP小于7份时,HBP／PVC的熔体表观粘度逐渐增加;当PVC中加入HBP等于7份时,HBP／PVC的熔体表观粘度出现最大值;当PVC中加入HBP大于7份时,HBP／PVC的熔体表观粘度减小。差示扫描量热仪(DSC)研究结果证明了HBP和PVC相容性较好,且与测得的流变行为结果相一致。从化学反应和形成氢键的机理解释了HBP／PVC的相容性。     

The Initial Thermal Stability of Poly(vinyl chloride)

The use of a fluidised bed reactor and a conductivity cell provide a technique for the study of degradation of PVC with greatly increased sensitivity. The kinetics of the reaction may be studied at 350 K and for small (1%) amounts of degradation. The effects of diffusion within the particles may be distinguished from that of diffusion in the surrounding atmosphere. The influence of temperature and particle size and sintering were examined. The catalytic effect of HCl was confirmed and an apparent activation energy of 29 kcal mol^?1 was observed.     

气相色谱-质谱联用法测定软聚氯乙烯塑料的挥发性气体

采用气相色谱-质谱联用法,定性测定了软聚氯乙烯塑料（S-PVC）产生的挥发性气体。结果显示：软聚氯乙烯产生的挥发性气体主要为烃类化合物、醇和醛、酯等羰基化合物,产生气味的化合物是醇和羰基化合物,这些物质可由助剂带入或在塑料加工过程中热氧降解产生。     

复合引发剂存在下的氯乙烯聚合动力学

Kinetic models for the rate constants of vinyl chloride polymerization in the presence of initiator mixtures were proposed. They may be used to design the initiator recipes for the vinyl chloride polymerization with uniform rate at different temperatures at which various grades of poly(vinyl chloride) will be prepared.     

PP-HBP改性PP／PVO的流变行为

研究了聚丙烯接枝超支化聚（酰胺酯）（PPHBP）／PP／聚氯乙烯（PVC）共混体系的流变行为。讨论了PP-HBP用煮对PP／PVC共混体系流变行为的影响。结果表明，当PP／PVC共混体系中加入PPHBP不大于5份时，PP／PVC／PPHBP共混体系的表观粘度大于PP／PVc共混体系的；当加入PP—HBP大于5份时，PP／PVC／PP-HBP共混体系的表观粘度小于PP／PVC共混体系的；随着温度升高，PP／PVC和PP／PVC／PP—HBP共混体系表观粘度减小。     

抑烟剂对聚氯乙烯热分解特性的影响

采用热分析、实时傅立叶变换红外光谱等手段，研究了几种常用的抑烟剂(钼化合物和铁化合物)对聚氯乙烯(PVC)热分解特性和热氧化降解特性的影响。热失重的实验结果表明，添加抑烟剂的PVC分解后的残渣量与不含抑烟剂的PVC相比，都有所提高，尤其是含有钼酸铵、氧化钼或Fe2O3的PVC复合物。实时FTIR表明抑烟剂改变TPVC热氧化降解历程，并对C-H和C-Cl键的分解产生较大的影响。     

Rheological Behavior and Mechanical Properties of Blends of Poly(vinyl chloride) with CP-POSS

In this work, a polyhedral oligomeric silsesquioxane which contains 3-chloropropyl groups (CP-POSS) was synthesized. The rheological behavior of CP-POSS/PVC blends was investigated by torque rheometer and capillary rheometer. Mechanical properties were investigated by electronic material tester. Influences of blending composition, shear rate and shear stress on melt apparent viscosity and non-Newtonian index (n) were discussed. The results show that the plastic time decreases and melt viscosity increases with increasing content of CP-POSS. CP-POSS has a good compatibility with PVC. The blend has the best impact strength when the content of CP-POSS is 7 wt%. The CP-POSS can be used as a processing aid and impact-resistant aid for PVC.