CPVC/PVC共混物性能研究

采用CPVC与PVC共混,研究共混物的力学性能和耐热性,并考察纳米CaCO3对其性能的影响.结果表明:随着CPVC含量的增加,共混物的拉伸强度、弯曲强度和耐热性能都有明显的提高,冲击强度则先增后减;随着CaCO3含量增加,共混物的冲击强度和耐热性能都逐渐提高,但拉伸强度和弯曲强度则呈下降趋势.     

氯化聚氯乙烯与聚氯乙烯共混物性能的研究

通过改变CPVC/PVC的树脂组成,研究了共混物的外观、耐热性、阻燃消烟性以及物理力学性能.结果表明,少量的CPVC树脂也会影响共混物的稳定性;只有CPVC含量大于60%,才能有效地改善共混物的耐热、阻燃等性能.     

NBR／PVC共混胶在燃油胶管中的应用

探讨了德国拜耳公司乳液共沉法生产的NBR/PVC共混胶料填充各种常用配合剂后的物理性能的变化,介绍了NBR/PVC共混胶在耐燃油胶管中的应用配方和制造工艺。     

ABS/PVC合金的热稳定性分析

通过热烘变色试验,对ABS／PVC合金的热稳定性进行分析。结果表明,所试验的三种PVC专用热稳定剂会加速ABS树指的热老化;当ABS／PVC合金比例为60／40时,其热稳定性较佳;CPE对合金的热烘变色有利;有机锡热稳定剂的效果最好。     

Immiscible Blends of PC and PET,Current Knowledge and New Results: Rheological Properties

This paper deals with immiscible blends of poly(ethylene terephthalate) obtained by melt blending with polycarbonate. A large survey of the current knowledge in the field of these blends is presented. Resolved and unresolved issues concerning the effect of exchange reactions on the miscibility of the components are addressed. The experimental part of the paper focuses on the rheological behavior of PET/PC blends. Blends containing various polymer ratios were obtained by melt blending with and without transesterification catalysts. Oscillatory shear flow in the melt was used to characterize the rheology of the various samples. A plot of the oscillatory data, similar to the Van Gurp Palmen plot, is used to point out the broadening of the co‐continuity window when in situ compatibilization takes place.

     

CPVC对PVC性能的影响

研究了在PVC中添加不同量的CPVC共混体系的加工性能、耐热性能、力学性能。实验结果表明:随着CPVC含量的增加,共混体系的加工性能变的较为困难,但拉伸强度和维卡软化点温度有明显提高,缺口冲击强度和断裂伸长率有所下降。当CPVC用量为20份时,是实际生产及实际应用的一个较为理想的比例。     

Correlation of Sequence Block Lengths and Degree of Randomness with Melt Rheological Properties in PET/PEN Blends

PET/PEN blends were prepared over the full composition range via a melt mixing process under various processing conditions. This resulted in transesterification reactions and formation of copolymer structures with various average sequence block lengths and degree of randomness (RD) determined by ¹H NMR. It was seen that with an increase in time and temperature of mixing copolymer content (TEN%) and RD increased, whereas the , values were decreased. The differences in the extent of transreactions arising from different processing histories showed their systematic influence on rheological characteristics. Moreover due to progress of transreactions during the rheological measurements, convergence was seen in all the rheological characteristics at terminal zones in the high frequency regions. Similar convergence in the copolymer structural parameters was also obtained by NMR analysis. An increase in TEN% led to a systematic increase in viscosity of the blends. A decrease in the , values results in an increase in elasticity and relaxation time due to improvement of blend interface with increase in extent of copolymer formation.

     

PVC／EPDM共混体系的性能和结构

研究了增塑PVC/EPDM共混物的力学性能和形态结构,考察了不同增容剂的作用,发现CPE比EVA和NBR更好。同时,EPDM/CPE比值不应过大,且对不同聚合度PVC,该比值有不同要求。     

A Study of the Viscoelastic and Rheological Properties of PVC/CPE Blends Modified by Using Polylauryllactam

Abstract

Polylauryllactam was used to improve the impact strength of polyvinylchloride (PVC)/chlorinated polyethylene (CPE) blends without sacrificing their tensile properties. The enhancement of the impact strength increased with the increase of the CPE content in the PVC/CPE blends due to the formation of intermolecular hydrogen bonds among PVC, polylauryllactam and CPE macromolecules. A doubled impact strength of the PVC/CPE blend with 20 weight percent of CPE was obtained after the addition of 1.5 phr polylauryllactam. The PVC/CPE blends with polylauryllactam have a better dimensional stability compared with the PVC/CPE blends without the additive, according to their viscoelastic characteristics. Polylauryllactam shortened the processing time to reach a minimum melt viscosity in the processing of the PVC/CPE blends.     

PVC/SEBS共混体系性能的研究

以聚氯乙烯/苯乙烯-乙烯-丁二烯-苯乙烯嵌段共聚物(PVC/SEBS)为共混改性的研究对象,讨论了PVC的用量对共混物的加工流变性能和力学性能的影响。结果表明:当PVC含量达11%时,共混物的力学性能有所提高,同时加工流变性能也有了很大改善。     

固相法氯化聚乙烯与聚氯乙烯共混物的形态与性能

研究了聚氯乙烯(PVC)与固相法氯化聚乙烯(CPE)共混物的应力-应变行为和冲击强度对CPE用量和氯含量的依赖关系,考察了共混物形态与性能的关系。动态力学性能和透射电子显微镜的研究结果表明,PVC/CPE为部分相容体系,两相间存在着一定的相互作用,当CPE氯含量为36％～42％,用量为7～15份时,CPE在PVC/CPE共混物中形成比较完整的网络结构、共混物具有更好的抗冲击性能。Brabender流变仪研究表明,CPE能促进PVC的塑化,共混物的加工性优于纯PVC。     

影响CR/CIIR硫化胶耐热老化性能的因素

研究了共混比、硫化体系、炭黑品种及用量、软化剂种类等对CR/CIIR硫化胶耐热老化性能的影响。结果表明,100℃×48h热老化后,CR/CIIR硫化胶的力学性能保持率随CIIR用量的增加而提高;采用TCY/树脂复合硫化体系硫化的CR/CIIR力学性能保持率相对较高;采用N550炭黑补强的硫化胶耐热老化性能良好,但用量不宜超过60份;软化剂对硫化胶的耐热老化性能也有一定影响。     

浅谈硬质PVC混料

针对硬质PVC混料的热混出料温度、混料顺序以及干混料的熟化时间等混料参数对干混料的加工行为的影响进行了探讨,同时对混料设备的选择、混料加料量及如何判断干混料的优劣做了简要的说明。     

PVC／HRA共混物耐热与力学性能研究

以ＰＭＩ－Ｓｔ－ＡＮ三元共聚物为热改性剂,以ＡＣＲ为抗冲改性剂,对ＰＶＣ进行耐热和抗冲改性研究,探讨了共混温度及两种改性剂用量等对共混物物理。力学性能和耐热性能的影响,通过优化制备了耐热,抗冲性能兼备的ＰＶＣ共混改性新材料。     

塑料热变形温度测试影响因素的探讨

文章通过依据不同标准所规定的测试方法进行塑料热变形温度（HDT）测量,找出测量结果之阅的规律;同时研究了测量热变形温度过程中使用的硅油的黏度对测量结果的影响,提出更换硅油频率的建议;还探讨了测量起始温度对测量结果的影响。     

PVC／TPU／SBS—g—MMA共混体系研究

制备了ＳＢＳ－ｇ－ＭＭＡ系列接枝共聚物,并对其进行了表征。以ＳＢＳ－ｇ－ＭＭＡ作为ＰＶＣ／ＴＰＵ共混体系的增容剂,对不同配比的ＰＶＣ／ＴＰＵ／ＳＢＳ－ｇ－ＭＭＡ共混体系的物理力学性能、流变性等进行了研究。结果表明,ＳＢＳ－ｇ－ＭＭＡ接枝共聚物对ＰＶＣ／ＴＰＵ共混体系起到了明显的增容作用。     

Preparation and Assessment of Phase Morphology,Rheological Properties,and Thermal Behavior of Low-Density Polyethylene/Polyhexene-1 Blends

In this work, polyhexene-1 (PH-1) is synthesized by polymerization of hexane-1 with Ziegler–Natta catalyst and melt blended with low-density polyethylene (LDPE). The phase morphology, rheology, crystallization, and thermal behavior of (LDPE)/PH-1 blends are investigated. A good compatibility is observed in the blends up to 10?wt% PH-1 and the most of the droplets in the fractured surface are covered with and buried in the LDPE matrix and at higher percentage the droplet particle size significantly increased. The effect of microstructure of the blends on the flow behavior is studied by small amplitude oscillation rheology. By decreasing the compatibility and increasing the particle size, the Cole–Cole plots are deviated from the semi-circular shape at higher percentages than 10?wt% of PH-1. The change in the crystallization and melting behavior of LDPE in the blends are studied by differential scanning calorimetry and X-ray diffraction (XRD). It is found that by increasing the PH-1 the melting temperature of LDPE decreased from 112.5 to 110.8°C and crystallization temperature increased from 95.2 to 97.7°C which is evident of the nucleation effect. The intensity of (110) peak in XRD test declined as a remake of amorphous part of LDPE and the degree of crystallinity of LDPE decreased from 28 to 22% at 20?wt% PH-1.     

PVC/SMAH共混物的研究

研究了聚氯乙烯（PVC）与（苯乙烯／马来酸酐）共聚物（SMAH）的共混改性,测定了共混物的冲击强度、熔体流动速率和维卡软化点。SMAH可以显著地提高PVC的熔体流动速率和维卡软化点,但共混物的制品冲击强度降低。加入第三组分（乙烯／乙酸乙烯酯）共聚物（E／VAC）后,PVC／SMAH共混物的制品冲击强度提高。结构分析表明,PVC／SMAH共混物体系是典型的两相体系。     

Rheological and Mechanical Properties of LDPE/HDPE Blends

Melt rheology and mechanical properties of binary blend of low-density polyethylene (LDPE) and high-density polyethylene (HDPE) have been investigated. Four different wt fractions of blends containing LDPE/HDPE (20/80, 40/60, 60/40, and 80/20) were prepared. Cole-Cole plots [storage melt viscosity (η′) vs. loss melt viscosity (η″)] and relation between storage melt viscosity (η′) with frequency (ω) and blend composition were constructed. Miscibility of blends was established from rheological data. Impact strength of the blends increased with increasing LDPE concentration, whereas tensile strength shows the opposite trends. Percentages of the crystallinity of the blends were calculated by both the differential scanning calorimetry and wide-angle X-ray scattering methods, which show that the percentage of crystallinity decreased with increasing LDPE concentration, but the rate of crystallization of HDPE phase was unaffected.     

Binary and Ternary mLLDPE Blends: Tailoring Their Properties Using Complex Viscosity Measurements

Summary: Metallocene‐catalysed linear low density polyethylenes (mLLDPEs) of different molecular weights are mixed with a base mLLDPE to obtain a pre‐determined grade and a suitable extrusion processability. Complex viscosity results are revealed as a very suitable tool to tailor the properties of the prepared binary and ternary blends. The investigated blends show symptoms of miscibility like time‐temperature superposition and observance of Cox‐Merz rule. This allows to evaluate the molecular weight distribution, supplying also practical data related to the polyethylene grade and ‘sharkskin’ instability. The complex viscosity curve of a model sample that would have both, a suitable grade and processability, is created; blends are prepared to match the model curve. The blend with a low molecular weight mLLDPE shows a parallel shift of the complex viscosity to lower values (molecular weight distribution is not broadened), postponing sharkskin, but changing the polymer grade. Satisfactory results are neither obtained with blends of a high molecular weight mLLDPE. Best results are obtained with ternary blends, which combine the modifications provided by low and high molecular weight mLLDPEs, approaching the complex viscosity and molecular weight distribution of the model.

Complex viscosity results of PR‐207 (– —), PR‐209 (···) and PR‐210 (– –) ternary blends, as compared with those of base samples PR‐201 (symbols) and the model (line).