硬质聚氯乙烯低发泡管材的单螺杆挤出成型

采用单螺杆挤出机进行了硬质聚氯乙烯低发泡管材挤出成型,研究了树脂牌号、预塑化对管材性能和泡孔结构的影响,探讨了口模与定型模的匹配问题,对比了普通口模与专用口模的差异及其对管材外观及性能的影响。结果表明,采用经预塑化的PVCS－1000树脂生产的管材具有优良的外观和理想的泡孔结构。专用发泡口模与普通口模相比,在压缩比相同的前提下,平行段长度由110mm缩短为50mm。     

低发泡硬质聚氯乙烯整体门板挤出成型

在低发泡硬质聚氯乙烯整体门板的挤出成型中 ,控制聚合物熔体的流动和发泡是保证产品质量的关键。对其基本生产工艺和原理进行了介绍 ,并分析了生产中的技术难点 ,提出了解决的办法。     

低发泡聚氯乙烯挤出合成木材技术

合成木材又称仿生塑料,已经被认定是木材良好的替代品。本文主要介绍低发泡聚氯乙烯挤出合成木材的国内外发展概况,基本生产工艺和原理。要获得外观和内在质量均优良的低发泡PVC制品,关键是要合理地设计配方,优化挤出工艺。实践证明,高质量的发泡体只是在适当的温度范围内才能获得。     

PVC低发泡实心板挤出成型技术要点

在PVC低发泡实心板挤出成型中,控制聚合物熔体的流动和发泡是保证产品质量的关键,重点介绍了生产工艺和原理,并分析了生产中的技术要点,提出了解决的办法。     

PVC低发泡塑料挤出的基本技术

主要叙述ＰＶＣ低发泡塑料挤了的基本技术及自由发泡法、Ｃｅｌｕｋａ发泡法基本原理及工艺。     

低发泡RPVC挤出成型的配方和工艺研究

提出了低发泡硬质聚氯乙烯挤出成型的配方和工艺。研究了稳定型,改性剂等配方因素对制品密度、表面、泡孔结构的影响,并讨论了制品密度与挤出工艺的关系。     

RPVC挤出低发泡材料延伸性能的研究

本文采用高温拉伸试验方法，系统地的 试验条件及材料组成的ＲＰＶＣ挤出低发泡工艺中ＰＶＣ熔体延伸形变性能的影响。结果表明：在２３￣１９２℃范围内，随着温度的升高，ＰＶＣ材料的伸强度降低，断裂伸长率呈凸凹形变化。     

AC在低发泡硬聚氯乙烯挤出配方中的应用

本文介绍了AC(偶氮二甲酰胺)发泡剂的热分解特性、低发泡硬聚氯乙烯配方设计要点和挤出用配方实例。     

低发泡HIPS挤出成型工艺的研究

利用试验设计方法研究了HIPS低发泡过程中,挤出温度及螺杆转速对发泡制品的表现密度,泡孔尺寸,泡孔尺寸均匀度以及制品强度的影响,实验结果表明：随着扩是出温度的提高,制品的表观密度会有所升高;螺杆转速与挤出温度对表观密度的影响存在交互作用,在较高的温度下,螺杆转速对表观密度没有显著的景,是在较低的温度下,随着螺杆转速的提高,表观密度会有所增大,另外,螺杆转速对泡孔尺寸以及泡孔尺寸分布均匀度有较显著的影响,随着螺杆转速的扣高,泡孔尺寸大小降低,并且泡孔尺寸均匀度提高,因而制品的强度较大,温度的提高对泡孔的尺寸影响不大,但使泡孔尺寸均匀度下降,在所研究的工艺条件范围内,选择较低的挤出温度及较高的螺杆转速有利于得到性能较好的低发泡制品。     

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.     

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.     

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。     

PVC/木粉复合材料的挤出研究

采用聚氯乙烯(PVC)与木粉制得PVC／木粉复合材料。研究了木粉的含量、偶联剂的类型和含量、邻苯二甲酸二辛酯(DOP)和抗冲改性剂氯化聚乙烯(CPE)的用量对复合材料性能的影响以及润滑剂含量对加工性能的影响。结果表明,当PVC与木粉用量比为7.0:3.0、偶联剂为木粉用量1.5％、DOP用量为PVC用量20.0％、CPE用量为PVC用量10.0％、润滑剂用量为PVC用量1.2％时,所得复合材料的综合性能较好。     

PVC—U挤出过程的节能研究

从理论上阐述了用预热物料的方法提高硬质聚氯乙烯（PCV－U）挤出过程能量效率的可行性，并通过相关实验进行了验证。     

Characterization of Poly(Vinyl Alcohol) and Poly(Vinyl Pyrrolidone) Co-polymer Blend Hydrogel Prepared by Application of Gamma Radiation

Hydrogel is prepared from a poly(vinyl pyrrolidone) (PVP) and poly(vinyl alcohol) (PVA) blend solution by gamma radiation with a ₆₀Co λ source at room temperature. Properties of the prepared hydrogel, such as gel fraction, gel strength swelling ratio, equilibrium water content, and water absorption in room temperature, were investigated. Blending hydrogel with PVP and PVA obviously increased the gel strength and decreased the swelling ratio of hydrogel. It was observed that the gel fraction increased while the swelling ratio and water content decreased with increased radiation dose, but gel strength increased up to a certain radiation dose and then decreased. The percentage of water absorption at room temperature increased with time but after a certain time it became steady and decreased with radiation dose.     

新型结构螺杆在PVC制品挤出中的应用

根据近年将新型结构螺杆用于PVC制品挤出成型的成功经验，分别对分流型、屏障型、分离型及变流道型等结构型式的螺杆在PVC制品挤出成型方面的应用及特点进行了论述。     

Oil Resistance of Dynamically Vulcanized Poly(Vinyl Chloride)/Nitrile Butadiene Rubber Thermoplastic Elastomers

Summary Dynamically cured poly(vinyl chloride)/nitrile butadiene rubber (PVC/NBR), thermoplastic elastomers (TPEs) were melt mixed at 150°C at 50 rev.min.^-1 with a Brabender Plasticorder. Curatives concentration was varied from 0 to 1 phr in order to study the effect of dynamic curing on the oil resistance of the plastified formulations. The compounds were characterized in respect to their mass swell, tensile properties, tear strength and hardness. The PVC/NBR formulations have been exposed to air and oil under otherwise identical conditions. The influence of oil and thermo-oxidative ageing on the mechanical properties were characterized at room temperature and 100°C. It was found that at ambient temperature the samples immersed in oil possessed similar properties to those that were exposed to air. Profound enhancement in mechanical properties were observed for both environments at 100°C. The observed scenario has been attributed to the increase in the degree of curing which was accompanied by a steady reduction in % mass swell with increased sulfur loading. The excellent mechanical behavior of the PVC/NBR TPEs even after immersing the samples in oil at 100°C evidenced for the good oil resistance of the materials.     

给水管用PVC的改性研究

采用活性碳酸钙和甲基丙烯酸甲酯-丁二烯-苯乙烯三元接枝共聚物(MBS)对PVC进行改性,研究了二者对改性PVC抗冲击性能的影响.结果表明,活性碳酸钙和MBS的加入,改性PVC的抗冲击性能可提高17.3％,改性PVC管在低温下的抗冲击性能得到明显提高.     

Mechanical Properties of Silane and Zirconate Coupling Agent-Treated Oil Palm Empty Fruit Bunch Fiber-Filled Acrylic-Impact Modified Poly (Vinyl Chloride) Composites

The influence of untreated and treated OPEFB content on the mechanical properties of acrylic impact-modified PVC was investigated. The formulations were first dry blended before being milled into sheets on a two-roll mill. Test specimens were then hot pressed. The modulus significantly increased while the impact and flexural strength insignificantly improved with increasing of treated OPEFB contents. The reduction in water absorption, the formation of new absorption bands and the slight number of treated fiber pulled-out proved that there was an interaction between fiber and matrix. However, this interaction was insufficient to enhance the impact and flexural strength significantly.