Comparison of the toughening mechanisms of poly(vinyl chloride)/chlorinated polyethylene and poly(vinyl chloride)/acrylonitrile–butadiene–styrene copolymer blends

In this study, the influence of chlorinated polyethylene (CPE) and acrylonitrile–butadiene–styrene copolymer (ABS) on the mechanical properties of poly(vinyl chloride) (PVC)/CPE and PVC/ABS hybrids were examined. The experimental results show that the toughness of the hybrids could be modified greatly by the introduction of CPE or ABS. The microstructure and impact surfaces of the blends were investigated by scanning electron microscopy and transmission electron microscopy. ABS dispersed in the form of particles or agglomerates in the PVC matrix, and CPE tended to disperse as a net structure. In the tensile test, ABS initiated crazes as stress concentrators to toughen the PVC matrix, whereas CPE, with the PVC matrix together, caused a yield deformation by shear stress to form a shear band. The formation of crazes and shear bands benefited the toughening of PVC, but to the different extent. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 916–924, 2003     

Styrene-co-acrylonitrile resin modifications of PVC/CPE blends

The effects of styrene-co-acrylonitrile resin (AS) on the mechanical properties, morphology, and plasticizing and rheological behaviors of poly(vinyl chloride)/chlorinated polyethylene(PVC/CPE) blends are studied. The results show that the impact strength and the tensile strength are all increased and the plasticizing and rheological behaviors are also improved when a certain amount of AS is added into PVC/CPE blends, which are different in characteristics and regularity from plastics toughened with elastomers. It is blends of brittle—ductile transition regions (i.e., PVC/CPE = 100/10, 100/15) that can obviously be toughened by AS. The analysis of the morphological structure shows that AS promotes the formation of a CPE network that embeds the primary particles of PVC. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1455–1460, 1997     

A study on PVC/LLDPE blends with solid-state-chlorinated polyethylene as compatibilizer

Chlorinated polyethylene (CPE) prepared by solid-state chlorination was used as compatibilizer for poly(vinyl chloride) (PVC)/linear low-density polyethylene (LLDPE) blends. Effects of CPE molecular structure on stress-strain behaviors, dynamic mechanical properties, and morphologies of PVC/LLDPE blends were studied by using SEM, TEM, DMA, and testing mechanical properties. The results showed that the compatibility of PVC/LLDPE blends was improved with the addition of CPE. Also, adhesion strength between the two phases and mechanical properties of the blends were increased. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 2535–2541, 1997     

CPE增韧硬质聚氯乙烯的结构形态和增韧机理

对氯化聚乙烯（CPE）改性聚氯乙烯（PVC）体系的性能随组成的变化进行了研究。用电子显微镜（TEM、SEM）考察了共混体系的形态结构。结果发现：PVC和CPE相容性较好，共混体系在断裂过程中产生网丝结构。网丝结构与CPE用量密切相关，是脆－韧转变后体系发生塑性变形的结果，是PVC基体韧性突增的主要原因。     

氯化聚丙烯对PP/PVC共混物性能的影响

以氯化聚丙烯(CPP)为增容剂,探讨了CPP不同含量下PP/PVC体系的力学性能、相容性、流变性能以及对应的微观结构,并与氯化聚乙烯(CPE)增容剂进行了比较。发现添加5份CPP可明显改善PP和PVC两相界面相容性,与PP/PVC体系相比,拉伸强度提高了61%,无缺口冲击强度提高了100%。此时CPP还起到了一定的增塑作用,共混体系加工性能较好。与CPE相比,含有CPP的共混体系拉伸强度较高。     

The influence of compatibilizers on nitrile-butadiene rubber and polypropylene (NBR/PP) blends

Four kinds of compatibilizers—chlorinated polyethylene (normal CPE), highly chlorinated CPE, maleic anhydride grafted with polypropylene (MP), and chlorinated polypropylene (CPP)—were used to study the influence of compatibilizing agents on the properties of nitrile-butadiene rubber and polypropylene (NBR/PP) blends, a kind of thermoplastic elastomer (TPE). The results show that the most proper amount of normal CPE, highly chlorinated CPE, MP, and CPP are 9, 8, 7, and 6 wt%, respectively, in the NBR/PP blends. The CPP was the best compatibilizer for NBR/PP blends among the four. NBR/PP blends obtained excellent properties of thermoplastic materials and can be molded with the general processing technologies for thermoplastics, such as injection, extrusion, blow molding, and the like. The mechanical properties are similar to that of Geolast, produced by Monsanto Company, and exceed the Chinese national criterion (GB7527-87). The tensile strength was 13.8 MPa; the elongation at break was 290%; and the compression set was 32%. After the blends were immersed in oil for 70 h, the tensile strength was 10.4 MPa, and the degree of oil absorption was 12%. The compatibility of the blends was consistent with the morphology from transmission electron microscopy (TEM).     

Compatibilizers for recycling of the plastic mixture wastes. II. The effect of a compatibilizer for binary blends on the properties of ternary blends

In this article, we discuss the effect of a compatibilizer for binary blends on the properties of ternary blends composed of high‐density polyethylene (HDPE), polypropylene (PP), or polystyrene (PS) and poly(vinyl chloride) (PVC) virgin polymers with a simulated waste plastics fraction. Chlorinated polyethylene (CPE), ethylene–propylene rubber (EPR), and their 1/1 (w/w) mixture were tested as compatibilizers for the HDPE/PP/PVC ternary blend. CPE, styrene‐ethylene‐propylene block copolymer (SEP), or their 1/1 (w/w) mixture were tested as compatibilizers for the HDPE/PS/PVC ternary blend. The composition of the ternary blends were fixed at 8/1/1 by weight ratio. The amount of the compatibilizer was 3 phr. Rheological, mechanical, and thermal properties were measured. For the 8/1/1 HDPE/PP/PVC ternary blends, the tensile strength was slightly decreased, but the impact strength was significantly increased by adding EPR, CPE, or their mixture. EPR exhibited the most significant impact modification effect for the ternary blends. In a similar way, for 8/1/1 HDPE/PS/PVC ternary blends, on adding SEP, CPE, or their mixture, the tensile strength was slightly decreased, but the impact strength was noticeably increased. It was found that the SEP worked much better as an impact modifier for the ternary blends than CPE or the SEP/CPE mixture did. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1048–1053, 2000     

PVC与CPE阻燃共混体系的研究

本文把氯化聚乙烯与阻燃剂并用对硬质聚氯乙烯改性而获得增韧阻燃的PVC制品。实验结果表明,阻燃剂的使用能提高复合共混体系的氧指数与耐热性,但影响材料的冲击强度与拉伸强度,合理的配方可使材料的阻燃和力学性能都达到要求。     

Studies of rigid poly(vinyl chloride) (PVC) compounds. I. Morphological characteristics of poly(vinyl chloride)/chlorinated polyethylene (PVC/CPE) blends

Chlorinated polyethylene (CPE) is a commonly used impact modifier of poly(vinyl chloride) (PVC). The major goal of this research was to understand the fundamental morphological aspects of PVC/CPE blends. Scanning electron microscopy (SEM) was used to image the surface structure of these blends, and both transmission electron microscopy (TEM) and scanning-transmission electron microscopy (S-TEM) were used to image the morphological boundaries of the blends. TEM imaging distinguishes the boundaries between PVC and CPE more clearly or better than does S-TEM, but it is time-consuming. However, some CPE particles are not observed in TEM because of inefficient staining. S-TEM imaging is much faster and does not depend on staining for the imaging of the CPE phase. © 1995 John Wiley & Sons, Inc.     

The experimental results and simulation of temperature dependence of brittle‐ductile transition in PVC/CPE blends and PVC/CPE/nano‐CaCO3 composites

The effect of chlorinated polyethylene (CPE) content and test temperature on the notched Izod impact strength and brittle‐ductile transition behaviors for polyvinylchloride (PVC)/CPE blends and PVC/CPE/nano‐CaCO₃ ternary composites is studied. The CPE content and the test temperature regions are from 0–50 phr and 243–363 K, respectively. It is found that the optimum nano‐CaCO₃ content is 15 phr for PVC/CPE/nano‐CaCO₃ ternary composites. For both PVC/CPE blends and PVC/CPE/nano‐CaCO₃ ternary composites, the impact strength is improved remarkably when the CPE content or test temperature is higher than the critical value, that is, brittle‐ductile transition content (C_BD) or brittle‐ductile transition temperature (T_BD). The T_BD is closely related to the CPE content, the higher the CPE content, the lower the T_BD. The temperature dependence of impact strength for PVC/CPE blends and PVC/CPE/nano‐CaCO₃ ternary composites can be well simulated with a logistic fitting model, and the simulation results can be illustrated with the percolation model proposed by Wu and Jiang. DMA results reveal that both PVC and CPE can affect the T_BD of PVC/CPE blends and PVC/CPE/nano‐CaCO₃ composites. When the CPE content is enough (20 phr), the CPE is more important than PVC for determining the T_BD of PVC/CPE blends and PVC/CPE/nano‐CaCO₃ composites. Scanning electron microscopy (SEM) observations reveal that the impact fractured mechanism can change from brittle to ductile with increasing test temperature for these PVC systems. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Miscibility,phase behavior,and mechanical properties of ternary blends of poly(vinyl chloride)/polystyrene/chlorinated polyethylene-graft-polystyrene

The effectiveness of chlorinated polyethylene-graft-polystyrene (CPE-g-PS) as a polymeric compatibilizer for immiscible poly(vinyl chloride)/polystyrene (PVC/PS) blends was investigated. The miscibility, phase behavior, and mechanical properties were studied using differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), Izod impact tests, tensile tests, and scanning electron microscopy (SEM). DSC and DMA studies showed that PVC is immiscible with chlorinated polyethylene (CPE) in CPE-g-PS, whereas the PS homopolymer is miscible with PS in CPE-g-PS. The PVC/PS/CPE-g-PS ternary blends exhibit a three-phase structure: PVC phase, CPE phase, and PS phase that consisted of a PS homopolymer and PS in CPE-g-PS. The mechanical properties showed that CPE-g-PS interacts well with both PVC and PS and can be used as a polymeric compatibilizer for PVC/PS blends. CPE-g-PS can also be used as an impact modifier for both PVC and PS. SEM observations confirmed, after the addition of CPE-g-PS, improvement of the interfacial adhesion between the phases of the PVC/PS blends. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 995–1003, 1998     

弹性体及无机粒子增韧PVC研究

利用丙烯酸酯类共聚物(ACR)、氯化聚乙烯(CPE)及甲基丙烯酸甲酯-丁二烯-苯乙烯共聚物(MBS)对聚氯乙烯(PVC)进行增韧改性。研究表明,随着弹性体用量的增加,拉伸强度呈小幅度下降趋势,冲击强度呈上升趋势,硬度略有下降;而不同种类的碳酸钙在增韧的同时还可较好地保持增韧体系的拉伸强度及硬度。     

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.     

Nanocomposites of poly(vinyl chloride) and nanometric calcium carbonate particles: Effects of chlorinated polyethylene on mechanical properties,morphology, and rheology

Nanocomposites of poly(vinyl chloride) (PVC) and nano‐calcium carbonate (CaCO₃) particles were prepared via melt blending, and chlorinated polyethylene (CPE) as an interfacial modifier was also introduced into the nanocomposites through preparing CPE/nano‐CaCO₃ master batch. The mechanical properties, morphology, and rheology were studied. A moderate toughening effect was observed for PVC/nano‐CaCO₃ binary nanocomposites. The elongation at break and Young's modulus also increased with increasing the nano‐CaCO₃ concentration. Transmission electron microscopy (TEM) study demonstrated that the nano‐CaCO₃ particles were dispersed in a PVC matrix uniformly, and a few nanoparticles agglomeration was found. The toughening effect of the nano‐CaCO₃ particles on PVC could be attributed to the cavitation of the matrix, which consumed tremendous fracture energy. The notched Izod impact strength achieved a significant improvement by incorporating CPE into the nanocomposites, and obtained the high value of 745 J/m. Morphology investigation indicated that the nano‐CaCO₃ particles in the PVC matrix was encapsulated with a CPE layer through preparing the CPE/nano‐CaCO₃ master batch. The evaluation of rheological properties revealed that the introduction of nano‐CaCO₃ particles into PVC resulted in a remarkable increase in the melt viscosity. However, the viscosity decreased with addition of CPE, especially at high shear rates; thus, the processability of the ternary nanocomposites was improved. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2714–2723, 2004     

Blends of PVC and epoxidized liquid natural rubber: Studies on impact modification

Liquid natural rubber of different molecular masses L‐LNR, and H‐LNR were subjected to varying degree of epoxidation (L‐ELNR‐10, L‐ELNR‐20, L‐ELNR‐30, L‐ELNR‐40, L‐ELNR‐50, H‐LNR‐20, and H‐LNR‐50) and the products were incorporated into PVC at various compositions by the solution blending method. These blend systems were subjected to tensile testing, tensile impact measurements, and SEM studies. It was observed that blends with L‐ELNR‐20 showed highest impact strength modification, followed by L‐ELNR‐10 and L‐ELNR‐30. High impact properties showed by these blends are attributed to the optimum level of compatibility existing between the blend components. Tensile impact fracture studies revealed that the failure pattern for this blend system is intermediate between the brittle fracture of rigid PVC and ductile fracture of PVC/L‐ELNR‐50 samples. Blends up to 30 mol % of epoxidation showed partially compatible heterogeneous nature exhibiting domain morphology. Blends of liquid rubber with higher degree of epoxidation showed deterioration in tensile strength, modulus, yield strength, and tensile impact strength due to plasticization of PVC caused by the higher polar interaction between PVC chains and the oxirane rings. Effect of ELNR molecular weight was studied and it is found that the impact modification is higher for the L‐ELNR blends compared to the H‐ELNR blends. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Study of poly(vinyl chloride)/acrylonitrile–styrene–acrylate blends for compatibility,toughness, thermal stability and UV irradiation resistance

A novel rigid poly(vinyl chloride) (PVC)/acrylonitrile–styrene–acrylate (ASA) copolymer blend with good ultraviolet (UV) irradiation resistance and toughness was reported. ASA with good weatherability and toughness was mixed with PVC by conical twin‐screw extruder to improve the UV irradiation resistance and toughness of PVC. The blends were characterized using Fourier‐transform infrared spectra, dynamic mechanical analysis, and scanning electron microscope. Notch Charpy impact test was used to characterize the UV radiation induced changes in toughness. The results showed that ASA was able to toughen PVC with simultaneously improving heat resistance, thermal stabilization, and protecting PVC from irradiation photochemical degradation. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2143–2151, 2013     

MBS粒子尺寸对PVC／MBS共混物性能及形变机理的影响

通过乳液聚合方法制备了两种不同粒径（分别为270nm和80nm）的甲基丙烯酸甲酯/丁二烯/苯乙烯（MBS）核壳改性剂，与聚氯乙烯（PVC）进行熔融共混，得到了PVC／MBS共混物。对PVC／MBS共混物力学、光学等方面的性能及其形变机理分别进行了考察。结果表明：PVC／MBS共混物的脆-韧转变温度（BDT）和拉伸性能均随着MBS粉料粒径的增加而增加；但是光学测试则表明MBS粒子对改善PVC基体的光学性能的效果却随MBS粉料粒径的增加而降低；透射电镜（TEM）的分析表明大粒径的MBS粉料能促使橡胶粒子产生空洞化，而由小粒径的MBS粉料制备的PVC／MBS共混物没有观察到橡胶粒子空洞化的产生。     

Effects of core‐shell acrylate particles on impact properties of chlorinated polyethylene/polyvinyl chloride blends

The impact properties of core‐shell acrylate (CS‐ACR)/chlorinated polyethylene (CPE)/poly(vinyl chloride) (PVC) blends under different temperatures were investigated. The fracture surface morphologies of the blends were observed by scanning electron microscopy (SEM). The results show that there exists significant synergistic effect between CS‐ACR particles and CPE in toughening PVC, and the impact properties of the blends generally correlate well with SEM morphologies. Besides, with increasing CS‐ACR content, ductile–brittle transition point of the ternary blends remarkably shifts to a lower temperature. Dynamic mechanical analysis exhibited that intensity and area of low‐temperature tan δ peaks of the CPE/PVC blends increase obviously after the addition of CS‐ACR particles, which to some extent are just in line with the changes in impact strength and ductile–brittle transition point of the blends. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

Morphology evolution of immiscible LDPE/PVC blends in the presence of compatibilizer and phase dispersant

Phase dispersion and coalescence in low‐density polyethylene (LDPE)/polyvinyl chloride (PVC) (70/30) blends influenced by compatibilizer and phase dispersant was studied. It was found that the morphology evolution of blends is sensitive to not only processing conditions (shear strength and mixing time) but also the added compatibilizer or phase dispersant. In our conditions, the stable phase morphology of each blend is obtained after mixing 15–25 min. In addition, the dispersed PVC phase in blends is easy to aggregate when the mixing rotor speed changed from high to low for the binary blends. As a compatibilizer, chlorided polyethylene (CPE) or nitrile rubber (NBR) can stabilize the morphology and hinder the coalescence of the dispersed PVC phase when added to the blends. However, the phase dispersant butadiene rubber (BR) or styrene butadiene rubber (SBR) could not stabilize the phase structure, although it could accelerate phase dispersion. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 763–772, 2004     

弹性体及无机粒子协同增韧PVC研究

利用甲基丙烯酸甲酯-丁二烯-苯乙烯共聚物(MBS)、氯化聚乙烯(CPE)及碳酸钙(CaCO3)对聚氯乙烯(PVC)进行协同增韧改性.研究表明,固定MBS用量,随着CaCO3用量的增加,拉伸强度及冲击强度呈先上升后下降趋势,而硬度变化不大;固定CPE用量,随着CaCO3用量的增加,拉伸强度呈下降趋势,冲击强度呈上升趋势,而硬度基本保持不变.