聚氯乙烯/丁腈胶粉共混型热塑性弹性体

将聚氯乙烯与废丁腈胶粉经高温机械共混，制备了动态交联的共混型热塑性弹性体。讨论了共混比，硫化体系及其用量，废胶粉品种（丁腈胶粉，轮胎胶粉）等因素对热塑性弹性体性能的影响，同时将聚氯乙烯／丁腈胶粉与聚氯乙烯／轮胎胶粉制备的共混型热塑性弹性体的性能进行了比较。结果表明，以聚氯乙烯100份（质量份，下同），邻苯二甲酸二辛酯50份，丁腈胶粉80份，丁腈橡胶20份，过氧化二异丙苯0．5份，氧化锌5份及适量其他助剂可制得综合性能较好的共混型热塑性弹性体。扫描电镜结果显示该共混型热塑性弹性体具有较好的相容性。     

Plastification of poly(vinyl chloride) by polymer blending

Blends of poly(vinyl chloride) (PVC) with different copolymers have been studied to obtain a plasticized PVC with improved properties and the absence of plasticizer migration. The copolymers used as plasticizers in the blends were acrylonitrile butadiene rubber, ethylene vinyl acetate (EVA), and ethylene-acrylic copolymer (E-Acry). Blends were studied with regard to their processing, miscibility, and mechanical properties, as a function of blend and copolymer composition. The results obtained were compared with those of equivalent compositions in the PVC/dioctyl phthalate (DOP) system. Better results than PVC/DOP were obtained for PVC/acrylonitrile butadiene rubber blends. The plasticizing effect on PVC of EVA and E-Acry copolymers was similar to that of DOP. It is shown that crosslinking PVC/E-Acry blends or increasing the vinyl acetate content in PVC/EVA blends, are alternatives that can increase the compatibility and mechanical properties of these blends. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1303–1312, 2000     

改性矿物填料增强橡胶/聚氯乙烯共混体系

研究了橡胶、增塑剂、矿物填料和表面处理剂对橡胶／聚氯乙烯(PVC)共混物力学性能的影响,用扫描电镜分析了有机胺类表面处理剂改性高岭土／丁腈橡胶(NBR)／PVC的界面结合状况。结果表明,当NBR用量为30份,邻苯二甲酸二辛酯用量为60份,有机胺类表面处理剂质量分数为3％,填充60份的超细碳酸钙或高岭土或牌号为SMF的蒙脱土时,可得到力学性能较佳的NBR／PVC共混物;不同矿物填料对NBR／PVC共混物的增强作用不同,经有机胺类表面处理剂改性后,以超细碳酸钙、高岭土和蒙脱土SMF的增强效果最为明显。     

Alloying of poly(vinyl chloride) to reduce plasticizer migration

Concern over the migration of low molecular weight plasticizer from flexible poly(vinyl chloride) (PVC) used in toys and medical products has spearheaded the commercialization of a number of plasticizing polymers. In this study the plasticizing behavior of an ethylene/vinyl acetate/carbon monoxide terpolymer (Elvaloy® from DuPont) was investigated. Blends of PVC, Elvaloy 742, and dioctyl phthalate (DOP) were processed on a twin‐roll mill and compression molded into plaques. These materials were characterized in terms of their hardness, glass‐transition temperature (T_g), clarity, mechanical properties, and plasticizer migration behavior. The ratios of PVC/DOP/Elvaloy investigated were determined by experimental design. Using this approach it was possible to model the results and produce contour plots to map out the properties of a wide range of formulations. It was confirmed that Elvaloy 742 is compatible with PVC and has a plasticizing effect: this was demonstrated both in terms of a reduction in Shore A hardness and a reduction in T_g. Plasticizer migration was reduced in proportion to the amount of liquid plasticizer replaced. Plasticizing with Elvaloy gave an improvement in tear strength. However, at constant hardness there was no improvement in tensile strength from replacing DOP with Elvaloy. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2022–2031, 2004     

氢化丁腈橡胶与聚氯乙烯或聚乙烯共混

研究氢化丁腈橡胶（HNBR）与聚氯乙烯（PVC）或聚乙烯（PE）的共混，该HNBR是用偶氨法常压氢化丁腈胶乳制得的。共混物的力学性能表明，在HNBR质量分数为40％以上时，2种共混物均呈现热性橡胶性能。HNBR／PVC共混物在拉伸强度方面呈现加和关系。热老化后HNBR／PE共混物的力学性能比NBR／PE共混物的好得多。用扫描电镜观察HNBR／PE 混物的断面形态。并用DSC曲线研究了HNBR／PE共混物的结晶变化。     

Studies on polyblends of poly(vinyl chloride) and acrylonitrile-butadiene-styrene terpolymer

Blends of poly (vinyl chloride) (PVC) and acrylonitrile-butadiene styrene (ABS) terpolymer were prepared in different ratios by a melt blending technique. ABS containing three different levels of rubber content were used. A quantitative assessment of ABS in PVC/ABS blends has been shown by infrared studies. ABS content has been shown as the presence of the characteristic acrylonitrile peak. Differential scanning calorimetry (DSC) studies have been carried out to study the glass transition (T_g) behavior of the blends. Two T_g values corresponding to PVC and styrene-acrylonitrile (SAN) copolymer have been observed. Thermogravimetric analysis (TGA) reveals a significant improvement in thermal stability of these blends as compared to PVC. Mechanical properties show a significant increase in the impact strength which is related to rubber content of the ABS used. Morphological studies have been carried out by scanning electron microscopy which support the observation that an increase in rubber content results in greater ductility.     

Application of new oligomeric plasticizers based on waste poly(ethylene terephthalate) for poly(vinyl chloride) compositions

In this study, chemical recycling products of waste poly(ethylene terephthalate) with oligoesters were used as new plasticizers for poly(vinyl chloride) (PVC). The preparation conditions of the dry blend mixtures of the suspension PVC containing synthesised plasticizers were similar to the conditions of the preparing mixtures with commercial plasticizers. The plasticization efficiency of PVC plasticizers was then examined by analysis of the mechanical, physical and chemical properties, as well as the thermal resistance and migration of plasticizer molecules from polymer matrix. Test results proved that compositions with synthesised oligomeric plasticizers possessed similar or better properties than those containing commercial oligomeric plasticizers and much better properties than those having monomeric plasticizers. Thermal stabilities of the proposed plasticizers were higher than those of the commercial plasticizers either monomeric (bis(2-ethylhexyl)phthalate) or oligomeric, despite the fact that the synthesised oligoesters did not contain any antioxidant. The best properties, especially low volatility, very good mechanical properties, low migration were resulted of the transesterification of the waste PET with oligoesters based on adipic acid, triethylene glycol and 2-ethylhexanol which were selected as plasticizers synthesised on the technical scale. The tested plasticized PVC compositions possessed very good tear resistance, tensile strength, decrease of weight loss after 168 h at 80 °C and low migration. Processing properties of PVC compositions containing these synthesised plasticizers confirmed their effectiveness in these compositions for extrusion process.     

Synthesis of a secondary plasticizer for poly(vinyl chloride) by recycling of poly(ethylene terephthalate) bottle waste through aminolytic depolymerization

This study focuses on the synthesis and application of didecanoate of bis(3‐hydroxypropyl) terephthalamide (DD‐BHPTA) as a secondary plasticizer in poly(vinyl chloride) (PVC) compounding. DD‐BHPTA was synthesized from poly(ethylene terephthalate) bottle waste through aminolysis followed by condensation reaction with decanoic acid. Synthesized DD‐BHPTA was characterized by Fourier‐transform infrared spectroscopy, differential scanning calorimetry, and nuclear magnetic resonance. Plasticized PVC was prepared by compounding PVC in different ratios with DD‐BHPTA and dioctyl phthalate (DOP) using a two‐roll mill. This newly synthesized plasticizer completely fused with PVC. The mechanical, thermal, and rheological properties like glass transition temperature, tensile strength, % elongation, dynamic mechanical analysis, solvent resistance, accelerated ultraviolet weathering test for color stability, differential scanning calorimetry, and thermal gravimetric analysis of plasticized PVC were investigated. DD‐BHPTA along with DOP plasticizer demonstrated plasticization efficiency similar to that of DOP alone, with the same plasticizer loading. DD‐BHPTA was found to be the more efficient plasticizer when used in combination with DOP. Thus, DD‐BHPTA can be used as a secondary plasticizer for DOP and can substitute DOP up to 50% of plasticizer loading. J. VINYL ADDIT. TECHNOL., 23:152–160, 2017. © 2015 Society of Plastics Engineers     

Mechanical properties of poly(vinyl chloride)/wood flour/glass fiber hybrid composites

Short glass fibers were added to poly(vinyl chloride) (PVC)/wood flour composites as reinforcement agents. Unnotched and notched impact strength of PVC/wood flour/glass fiber hybrid composites could be increased significantly without losing flexural properties by adding type L glass fibers and over 40% of PVC. There was no such improvement when using type S glass fiber. The impact strength of hybrid composites increased along with the increment of the type L glass fiber content at a 50% PVC content. At high PVC contents, impact fracture surfaces were characterized by wood particle, glass fiber breakage and pullout, whereas interfacial debonding was the dominant fracture mode at higher filler concentrations. The significant improvement in impact strength of hybrid composites was attributed to the formation of the three‐dimensional network glass fiber architecture between type L glass fibers and wood flour.     

Investigation of multiphase polymeric systems of poly(vinyl chloride)/ethylene-propylene-diene-gp-(styrene-CO-acrylonitrile) blends

The graft copolymer, ethylene-propylene-diene rubber (EPDM)-gp-(styrene-co-acrylonitrile) has been synthesized by solution precipitation polymerization using benzoyl perixide as initiator. The graft copolymer has been characterized after separation through soxhlet extraction by IR, NMR, and elemental analysis techniques. The graft copolymer of EPDM is melt blended with PVC. The nature of compatibility of the graft copolymers with PVC has been studied by means of morphological analysis and by thermal analysis. The mechanical properties, Izod impact strength, tensile strength, and flexural modulus of the blends are extensively studied over the wide range of concentrations. The results of both compatibility and mechanical properties are compared with those of PVC/EPDM blends. The nature of compatibility obtained shows that PVC/EPDM blends are incompatible and the PVC/EPDM-gp-SAN system is semicompatible. Also, these results indicate that the PVC/EPDM-gp-SAN system has its highest impact strength at 14 wt% of EPDM/gp-SAN graft copolymer. The fractured surface analysis of the impact fractured samples is also undertaken by an SEM technique. The results of the mechanical properties are discussed in view of existing theories of impact modification, along with the morphological feature of fractographs.     

Synthesis and characterization of polymeric plasticizer from PET waste and its applications in nitrile rubber and nitrile–PVC blend

Polyethylene terephthalate (PET) waste is not biodegradable; thus, it will create environmental hazards if disposed in landfills. Therefore, the only way of addressing the problem of disposal of post-industrial and post-consumer PET wastes is through recycling. The polyester plasticizer for polyacrylonitrile butadiene rubber (NBR) and polyacrylonitrile butadiene–polyvinylchloride rubber blend (NBR–PVC) was obtained by the depolymerization of PET waste with 2-ethyl-1-hexanol. The PET waste was depolymerized until a polymeric plasticizer with the average molecular weight in the range of 450–900 g/mol was obtained. The polymeric plasticizer was characterized for acid and hydroxyl numbers, viscosity, density, FTIR, NMR and TGA/DTA thermogram. The prepared polymeric plasticizer was used in the preparation of nitrile rubber and nitrile–PVC rubber blend rubber sheets, where these sheets were tested for compatibility, tensile strength, elongation-at-break, hardness and ageing properties. Nitrile rubber and nitrile–PVC blend sheets were also prepared using DOP as a plasticizer and a comparative study with the synthesized polymeric plasticizer was made. It was observed that synthesized polymeric plasticizer provides excellent tensile properties and ageing resistance for high-performance applications as compared to that obtained from DOP. The end uses for nitrile rubber and nitrile–PVC rubber blend compounds are quite diverse, but they can be loosely categorized as being either general performances or higher performance applications. Each of these performance categories requires a different set of considerations in terms of compounding with plasticizers.     

Blends of poly(vinyl chloride) with acrylonitrile-chlorinated polyethylene-styrene copolymer. II. Mechanical properties

Blends of poly(vinyl chloride) (PVC) and acrylonitrile-chlorinated polyethylene-styrene (ACS) graft copolymer were prepared by melt blending. Mechanical properties were studied by the use of dynamic mechanical analysis (DMA), impact tests, tensile tests, and scanning electron microscopy (SEM). The DMA study showed that PVC is immiscible with chlorinated polyethylene in ACS but partially miscible with poly(styrene-co-acrylonitrile) (25% acrylonitrile content) in ACS. Mechanical property tests showed that there is a significant increase in the impact strength while other good mechanical properties of PVC such as high modulus and high strength remain. SEM observations supported the results of the mechanical properties studies. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 399–405, 1997     

Effect of concentration and type of plasticizer on some physical properties of poly(vinyl chloride)

The effect of four different types and concentrations of plasticizers on some physical properties of poly(vinyl chloride) (PVC) has been studied. DOP, DOA, TTP, and Hex were used as plasticizers in concentration levels of up to 24% of PVC weight. The plasticized and unplasticized PVC were processed into sheets by compression molding. The sheets were tested for their vicat softening point, shore D hardness, flexural properties, and dynamic fatigue. It was found that the vicat softening point, shore D hardness, flexural yield strength, and flexural modulus decrease with increase in plasticizer concentration, though in some cases a threshold concentration must be passed before these effects can be observed. Close similarities were always found in the behavior of DOP and DOA and also between TTP and Hex. It was found in the study of flexural fatigue properties of PVC plasticized by DOP that an increase in plasticizer concentration led to a decrease in load bearing ability only at stress levels above 20 MPa.     

Effect of modifier characteristics on toughness of poly(vinyl chloride)

The effects of the mechanical properties of an acrylic graft copolymer and a silicone/acrylic composite rubber graft copolymer on the toughening of poly(vinyl chloride) (PVC) are examined. In the experiment for improvement of impact resistance of PVC, toughness of the blend polymer of a silicone/acrylic composite rubber graft copolymer is improved remarkably. The effect is attributed to the suppression of stress concentration below the fibril strength of the polymer alloy effectively by releasing the constraint of strain resulting from easy void formation at low stress. © 1996 John Wiley & Sons, Inc.     

Electrical properties of poly(vinyl chloride) compositions

A sample of poly(vinyl chloride) (PVC) and a polar plasticizer consisting of dioctyl phthalate (DOP) and dibutyl phthalate (DBP) was prepared and found to possess inconvenient electrical properties (permittivity, dielectric loss, and conductivity). Different samples of PVC compositions were formulated from the PVC–DOP–DBP system and also variable proportions of a copolymer of 1-octadecene-maleic anhydride or its hexadecylester. Lead stearate as a heat stabilizer and kaolin as a filler were added. The effect of copolymer structure on the electrical properties of the PVC–DOP–DBP system was studied to obtain a plasticized PVC of good electrical insulation character. © 1993 John Wiley & Sons, Inc.     

Compatibility of poly(vinyl chloride) with epoxidized copolymers of butadiene-styrene

The compatibility of poly(vinyl chloride) (PVC) with epoxidized styrene-butadiene copolymers is examined at different levels of epoxidation. The copolymers modified were a random (SBR) containing 45 wt% styrene and a triblock (SBS) with 30 wt% bound styrene. Blends were examined in the complete composition range and the approximate levels of epoxidation to ensure blend miscibility were determined. Epoxidized SBS (ESBS) was more effective in miscibility compared with ESBR requiring a lesser degree of epoxidation (43 versus 46 mol%). Tensile properties of the ESBS/PVC blends showed the efficiency of ESBS as a polymeric plasticizer even at levels of epoxidation (ca. 35 mol%) where immiscibility sets in.     

Thermal properties of graphite‐loaded nitrile rubber/poly(vinyl chloride) blends

The thermal properties (thermal conductivity, thermal diffusivity, and specific heat capacity) of nitrile rubber (NBR)/poly(vinyl chloride) (PVC) blends were measured in the temperature range of 300–425 K. The incorporation of graphite into the NBR/PVC (30/70) matrix improved its thermal properties. Moreover, these properties slightly changed with the temperature. The thermal conductivity values of the prepared samples were compared with values modeled according to the Maxwell–Eucken, Cheng–Vachon, Lewis–Nielsen, geometric mean, and Agari–Uno models. The Agari–Uno model best predicted the effective thermal conductivity for the whole range of blend ratios and for the whole range of graphite contents in NBR/PVC (30/70)/graphite composites. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Mechanical Properties and Morphology of Nitrile Rubber Toughened Polystyrene

Mechanical properties and morphology of blends of polystyrene and finely powdered (uncrosslinked and crosslinked) nitrile rubber were studied with special reference to the effect of blend ratio. Blends were prepared by melt mixing polystyrene and nitrile rubber in an internal mixer at 180°C in the composition range of 0–20 wt% nitrile rubber. The tensile stress/strain properties and impact strength of the polystyrene/nitrile rubber blends were determined using injection molded test specimens. In comparison to the blends with uncrosslinked nitrile rubber, blends with crosslinked nitrile rubber showed higher tensile strength, elongation at break, Young's modulus, impact strength, flexural strength, and flexural modulus. The enhanced adhesion between the dispersed nitrile rubber phase and the polystyrene matrix results in an increase in mechanical properties. Scanning electron micrographs of the fractured surfaces confirm the enhancement in mechanical properties.     

废旧丁腈橡胶粉改性ABS的性能研究

采用熔融共混挤出的方法,制备了废旧丁腈橡胶粉不同掺量的丙烯腈-丁二烯-苯乙烯共聚物（ABS）复合材料,研究了废旧丁腈橡胶粉对复合材料力学性能、流动性能和热稳定性的影响。结果表明：废旧丁腈橡胶粉降低了ABS的拉伸强度和弯曲强度,提高了冲击强度,其适宜的掺量宜控制在5%以内;而且,WNBR的加入使复合材料的热稳定性得到提高,但降低了复合材料的流动性。     

Flame retardant flexible poly(vinyl chloride) compound for cable application

ZnO/MgO, ZnO/CaO, and ZnO/CaO/MgO can form solid solutions. The solid solution for we as flame retardant (SSFR) was obtained by annealing at 1023 K for 4.5 h in a muffle furnace. Flexible poly (vinyl chloride) (PVC) filled with SSFR and Sb₂O₃ was investigated by differential thermal analysis thermogravimetry. Limiting oxygen index (LOI), mechanical properties, and electrical properties were studied. The surface of the char formed after combusting of the PVC compounds was observed through scanning electron microscopy and the effect of the surface area to the LOI was also studied. The data suggested that a small amount of SSFR and Sb₂O₃ have good synergy and can greatly increase the LOI and the char yield, and that the thermal degradation temperature and the activation energy decreased. It can be concluded that the mechanism of SSFR is a condensed‐phase mechanism. Moreover, one can conclude that the surface area can enhance the LOI. All the results showed that SSFR is effective and safe as a flame retardant in flexible PVC. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3137–3142, 2003