粉末改性NR对SAN的增韧作用

用粒径小于０９ｍｍ的粉末改性ＮＲ（ＰＭＮＲ）与苯乙烯丙烯腈共聚物（ＳＡＮ）共混,研究共混体的力学性能及ＰＭＮＲ的性质对共混体冲击强度的影响。结果表明,ＰＭＮＲ对ＳＡＮ有显著的增韧效果。以交联ＮＲ的溶胀指数为１０９、乙烯基链质量分数和溶解度参数δ分别为０２０和９４９的３０份ＰＭＮＲ增韧ＳＡＮ,其共混体的Ｃｈａｒｐｙ式无缺口冲击强度可达６０ｋＪ·ｍ－２左右。用扫描电镜进行的冲击断面形貌分析表明,共混体的增韧机理以剪切屈服为主兼有多重银纹化。     

粉末改性NR的制备及其与PVC共混体的冲击韧性

用高分子膜树脂为包覆剂,以凝聚包覆法制备了粉末改性天然橡胶（ＰＭＮＲ）。影响产物粒径的主要因素是ＰＭＮＲ的乙烯基链含量和包覆剂用量。当乙烯基链含量≥３０％,包覆剂用量为５份,可得粒径为０．９～０．２３ｍｍ的ＰＭＮＲ。测定了ＰＶＣ／ＰＭＮＲ共混体的冲击强度。发现ＰＭＮＲ对ＰＶＣ有良好的增韧作用。乙烯基链含量分别为３０％、３５％和４０％三种类型的ＰＭＮＲ对ＰＶＣ具有相同的增韧效果,当其用量为１０质量份,共混体的Ｃｈａｒｐｙ缺口冲击强度可达６０ｋＪ／ｍ２左右。但乙烯基链含量不同的ＰＭＮＲ所含ＮＲ对ＰＶＣ的增韧效率有差异。乙烯基链含量为３５％和４０％两种类型的ＰＭ－ＮＲ所含ＮＲ的增韧效率最高,当其ＮＲ用量为４．２质量份,共混体即发生脆韧转变。ＴＥＭ和ＳＥＭ分析分别显示共混体的相结构为海－岛结构,冲击断面呈须根形貌。     

粉末生SBR对PVC的增韧作用

研究了粉末改性ＳＢＲ对ＰＶＣ的增韧作用，用ＴＥＭ、ＳＥＭ和ＤＳＣ对粉末改性ＳＢＲ与ＰＶＣ共混物进行了分析，发现粉末改性ＳＢＲ对ＰＶＣ有显著的增韧效果。当粉末改性ＳＢＲ用量由５份增加到１０份，共混物的冲击强度由１０－２０ｋＪ／ｍ＾２突然升高到８５－１００ｋＪ／ｍ＾２。这种突变是由改性ＳＢＲ在ＰＶＣ基体中的相形态由分散相转变为网状结构，导致共混物由脆性断裂过渡到韧性断裂造成的。ＤＳＣ分析显示改性ＳＢＲ     

FPE,CaCO3非弹性体增韧PVC／CPE体系的研究

介绍以ＰＥ固相接枝马来酸二丁酯（简称ＦＰＥ）非弹性体增韧ＰＶＣ／ＣＰＥ体系。在ＰＶＣ／ＣＰＥ＝１００／５．５及１００／１０（质量比）体系中,加入５．５质量份ＦＰＥ后,其缺口冲击强度由１３．５ｋＪ／ｍ２、３１．５ｋＪ／ｍ２提高到１８．１ｋＪ／ｍ２、４０．８ｋＪ／ｍ２;拉伸强度由４９．４ＭＰａ、４１．７ＭＰａ提高到５２．９ＭＰａ、４２．７ＭＰａ,表明ＦＰＥ对ＰＶＣ／ＣＰＥ体系具有增韧增强双重作用。在ＰＶＣ／ＣＰＥ／ＦＰＥ三元体系中,加入适量的ＣａＣＯ３＊也有增韧作用,添加５质量份时,体系的缺口冲击强度由１８．１ｋＪ／ｍ２提高到２４．１ｋＪ／ｍ２。通过流变性能的测试表明,ＦＰＥ的加入能改善体系的流动性能。此外,还用ＳＥＭ研究了体系的增韧机理,认为在ＰＶＣ／ＣＰＥ／ＦＰＥ体系中,ＣＰＥ属弹性体增韧类型,ＦＰＥ属非弹性体增韧类型,两种机理同时存在。     

粉末改性SBR对PVC的增韧作用

研究了粉末改性ＳＢＲ对ＰＶＣ的增韧作用。用ＴＥＭ、ＳＥＭ和ＤＳＣ对粉末改性ＳＢＲ与ＰＶＣ共混物进行了分析。发现粉末改性ＳＢＲ对ＰＶＣ有显著的增韧效果。当粉末改性ＳＢＲ用量由５份增加到１０份，共混物的冲击强度由１０～２０ｋＪ／ｍ２突然升高到８５～１００ｋＪ／ｍ２。这种突变是由改性ＳＢＲ在ＰＶＣ基体中的相形态由分散相转变为网状结构，导致共混物由脆性断裂过渡到韧性断裂造成的。ＤＳＣ分析显示改性ＳＢＲ与ＰＶＣ部分相容。     

粉末NBR对PVC的增韧作用

用交联包覆法制备的粉末丁腈橡胶（ＰＮＢＲ） 与ＰＶＣ 共混。研究了ＰＮＢＲ 的性质及用量对共混体冲击强度的影响。发现线型ＰＮＢＲ 对ＰＶＣ 有显著的增韧作用,当其用量（ 质量） 为１０ 份,共混体的Ｃｈａｒｐｙ 缺口冲击强度达７１ｋＪ／ ｍ ２ 。ＰＮＢＲ大分子的交联结构与包覆剂的存在会稍为降低共混体的冲击强度。共混体的脆韧转变发生在ＰＮＢＲ 用量（ 质量） 为７ ．５ ～１０ 份之间。共混体冲击断面形貌的ＳＥＭ 分析表明其增韧机理为剪切屈服机理。     

氯化乙丙橡胶胶增容PVC／SBS共混体系的研究

以氯化乙丙橡胶（ＣＥＰＤＭ）为相容剂,研究了ＳＢＳ对ＰＶＣ的共混增韧改性。结果表明ＣＥＰＤＭ能明显改善ＳＢＳ与ＰＶＣ的相容性,使共混物中ＳＢＳ颗粒尺寸明显减小,分布更均匀,共混物的ｔｇ内移,常常和低温下制品冲击强度增大。当ＰＶＣ／ＳＢＳ／ＣＥＰＤＭ为８０／２０／６（质量比）时,共混物的常温缺口冲击强度为５６．３ｋＪ／ｍ＾２,低温（－２０℃）缺口冲击强度为３２．４ｋＪ／ｍ＾２。     

ENR与PP-MAH双组分相容剂在胶粉增韧废PP材料中的作用研究

以环氧化天然橡胶（ＥＮＲ）与马来酸酐接枝聚丙烯（ＰＰＭＡＨ）双组分相容剂改性废ＰＰ／胶粉体系,探讨了相容作用实施的条件及相容剂的最佳用量配比,并考察了胶粉用量和细度对材料力学性能的影响。结果表明,ＥＮＲ与胶粉只有先通过机械剪切作用和硫化剂ＤＣＰ交联作用达到物理化学结合,才能使ＥＮＲ和ＰＰＭＡＨ双组分相容剂发挥有效的增韧作用;按照最佳工艺和最佳共混条件,ＰＰ用量为１００份,胶粉为２０份,ＥＮＲ和ＰＰＭＡＨ均为６份时,制得复合材料的冲击强度为１４１ｋＪ·ｍ－２,拉伸强度为１８５ＭＰａ;冲击断面扫描电镜观察表明,双组分相容剂的加入强化了ＰＰ与胶粉的界面相容。     

马来酸酐接枝SBS增容PVC／SBS的研究

马来酸酐接枝苯乙烯－丁二烯＝苯乙嵌段共聚物（ＳＢＳ）用ＭＳＢＳ代表,以它为增容剂,研究了ＳＢＳ对聚氯乙烯（ＰＶＣ０的共混增韧改性。结果表明：ＭＳＢＳ能明显改善ＳＢＳ与ＰＶＣ的相容必 分散相ＳＢＳ相区尺寸明显减小,分布更均匀,共混物的玻璃化转变温度内移,常温和低温下缺口冲击强度增大。当ＰＶＣ／ＳＢＳ／ＭＳＢＳ为７５：２５：４时,共混物的常温缺口冲击强度为５８．３ｋＪ／ｍ＾２,低温（－２０℃）缺口冲击     

CPE增容PVC／EPDM共混体系力学性能研究

以聚氯乙烯（ＰＶＣ）为主体材料，新型三元乙丙橡胶（ＥＰＤＭ）为改性剂，氯化聚乙烯（ＣＰＥ）为增容剂进行共混，来改善ＰＶＣ的抗冲击性能。实验结果表明，ＰＶＣ和一定量的ＣＰＥ、ＥＰＤＭ共混改性后，共混体系的冲击强度大幅度提高，ＰＶＣ／ＣＰＥ／ＥＰＤＭ在１００／５／１０（Ｗ／Ｗ）时，冲击强度上升值最大，可达４３．７ｋＪ／ｍ＾２，拉伸断裂强度提高近３０％。     

Toughening modification of (Acrylonitrile‐styrene‐acrylic copolymer)/(α‐Methylstyrene‐acrylonitrile copolymer) binary blend via using different impact modifiers

In this work, different impact modifiers such as acrylic resin impact modifier, chlorinated polyethylene (CPE), nitrile rubber, powdered nitrile rubber, and hydrogenated nitrile rubber, were chosen to improve the toughness of (acrylonitrile‐styrene‐acrylic copolymer)/(α‐methylstyrene‐acrylonitrile copolymer) (ASA/α‐MSAN) binary blend. The blend ratios of the ASA/(α‐MSAN)/(impact modifier) ternary system were 30/70/20 and 70/30/20 by mass, respectively. The results showed that the impact strength significantly increased, nearly 30 times (22.59 kJ·m^?2, 22.26 kJ·m^?2, and 25.24 kJ·m^?2) compared with that of control samples (0.80 kJ·m^?2) when nitrile rubber, powdered nitrile rubber, or hydrogenated nitrile rubber was added to the ASA/(α‐MSAN) (30/70) matrix, respectively. Moreover, the impact strength of ASA/(α‐MSAN) (70/30) was dramatically enhanced to 46 kJ·m^?2 with the addition of 20 parts by weight per hundred parts of resin of chlorinated polyethylene. The toughness of ASA/(α‐MSAN) with or without impact modifiers was also characterized via fracture energy calculated from stress‐strain curves. The results were perfectly consistent with that of impact strength. The results of dynamic mechanical analysis demonstrated the existence of α‐MSAN (glass transition temperature at approximately 140°C). The heat distortion temperature was barely changed, indicating the addition of impact modifiers barely affects the heat resistance. J. VINYL ADDIT. TECHNOL., 22:326–335, 2016. © 2014 Society of Plastics Engineers     

刚性聚合物改性PVC/CPE/CaCO_3共混体的研究

本文研究刚性聚合物(PS、PMMA)对CaCO_2填充的PVC/CPE共混体力学性能和流变性能的影响。结果表明,刚性聚合物的填入提高了共混体的冲击强度,其中,对PVC/CPE/CaCO_3=100/15/10体系的增韧效果较好。PMMA使共混体的拉伸强度有所提高而PS使共混体拉伸强度下降。流变性的测定显示,Ca-CO_2使共混体的表观粘度和粘流活化能增加,牛顿的流动性增强,而在PVC/CPE/CaCO_3共混体中加入4.5份PS能明显降低共混体的表观粘度和粘流活化能,牛顿的流动性降低,但仍有良好的挤出物外观和较低的挤出膨胀率。     

高分子量聚氯乙烯增塑体系及其改性研究

研究了ＨＭＷＰＶＣ和通用ＰＶＣ的增塑性能,采用ＣＰＥ、Ｐ８３ 和７４１ 改性剂对ＨＭＷＰＶＣ增塑体系进行改性,结果表明,随ＰＶＣ分子量增加,体系的拉伸强度,冲击回弹性,硬度、熔体平衡转矩、熔体温度提高,而软化温度和磨耗降低,动态热稳定时间缩短;ＤＯＰ用量的增加,呈现通常的增塑性能;加有ＣＰＥ的体系磨耗增加明显,７４１ 对体系的硬度,软化温度和冲击回弹性影响较显著,对于熔体性能的影响,则ＣＰＥ更为明显。     

Toughening of polypropylene combined with nanosized CaCO3 and styrene–butadiene–styrene

Nanocomposites of nanosized CaCO₃/SBS/PP were prepared by using twin‐screw and single‐screw extruder. By adding nanosized CaCO₃ particles into SBS/PP blend, the notched impact strength, flexural modulus, and tensile strength of the composites can be improved, whereas, by adding microsized CaCO₃ particles into SBS/PP blend, the notched impact strength of the composite is decreased markedly. At nanosized CaCO₃ content of 16 phr (parts per hundred PP resin by weight), the impact strength of nanosized CaCO₃/SBS/PP composite reaches 56.55 KJ/m², which is 1.27 times that of SBS/PP blend. At nanosized CaCO₃ content of 4 phr, the tensile strength of the composites reaches 31.3 MPa, which is 1.23 times that of SBS/PP blend. The maximum and balanced torque of the composites improves significantly by the addition of CaCO₃ nanoparticles. The increased shear force during compounding continuously breaks down SBS particles, resulting in the reduction of the SBS particles size, and improving the dispersion of SBS particles in PP matrix. Thus the toughening effect of SBS on matrix was improved. Simultaneously, the existence of SBS provides the matrix with a good intrinsic toughness, satisfying the condition that nanosized inorganic particle of CaCO₃ efficiently toughens polymer matrix. The synergistic toughening function of nanosized CaCO₃ and SBS on PP matrix was exhibited. POLYM. ENG. SCI. 47:201–206, 2007. © 2007 Society of Plastics Engineers     

Core–shell particles designed for toughening poly(vinyl chloride)

A novel core–shell modifier (MOD) made up of polystyrene and poly(butyl acrylate) (PBA) grafted on a crosslinked styrene‐co‐butadiene core was synthesized by emulsion polymerization. This modifier was used for enhancing effectively the impact ductility of poly(vinyl chloride) (PVC) without losing its transparency. The effects of the MOD on the properties of PVC/MOD blends were explored. It was found that the butyl acrylate (BA) content of the MOD was an important factor affecting the properties of PVC/MOD blends. The Izod impact strength of these blends reached 1200 J m^?1 when the MOD contained 40 wt% BA. The dispersion morphology of the MOD in the PVC matrix was investigated using transmission electron microscopy, with a uniform dispersion of the MOD with higher BA content being obtained. The toughening mechanism of PVC/MOD blends was also investigated. The presence of BA in the MOD enhanced the ductility of the PVC blends due to the increased amount of soft phase (PBA). The dispersion morphology indicated that the interfacial interaction between MOD particles and PVC matrix was improved due to the presence of PBA graft chain in the MOD. TEM of impact fracture samples showed that shear yielding of the PVC matrix and debonding of MOD particles were the major toughening mechanisms for the PVC/MOD blends. Copyright © 2010 Society of Chemical Industry     

Mechanical,thermal, and water uptake characteristics of woodflour‐filled polyvinyl chloride/acrylonitrile butadiene styrene blends

Woodflour‐filled composites based on polymeric blends of polyvinyl chloride (PVC) and super high‐impact grade ABS were developed. Mechanical, thermal, and water uptake characteristics of the PVC/ABS matrix and their wood composites were evaluated. In the case of PVC/ABS matrix, the blend at a mass ratio of 50/50 rendered the impact strength with a very high value of up to 65 kJ/m², noticeably higher than those of the parent resins, that is, 6 kJ/m² of PVC and 35 kJ/m² of ABS. Dynamic mechanical analysis thermograms showed two distinct glass transition temperatures (T_gs) that shifted toward each other indicating partial miscibility of the blends. Water absorption of the blends after 24 h immersion was low, that is, within the range of 0.04–0.2 wt % and exhibits a behavior closed to pseudo‐Fickian type. The obtained PVC/ABS wood composites exhibited an increase of flexural modulus as well as T_gs with an increase of woodflour content. Finally, impact strength of the PVC/ABS composites was significantly higher than those of PVC composites or polyethylene composites comparing at the same woodflour content. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Dynamic rheological behavior and mechanical properties of PVC/ACS blends

In order to increase the processability and mechanical properties of poly(vinyl chloride) (PVC), the terpolymer of acrylonitrile-chlorinated polyethylene-styrene (ACS) is used to modify the PVC. The plasticizing, rheological, and dynamic mechanical properties of PVC/ACS blends are investigated by means of torque rheometer, oscillation rheometer, and dynamic mechanical analyzer. The measurements of torque rheometer showed that both plasticizing time and stabilization torque are decreased with increasing ACS content. The PVC/ACS melts displayed larger dynamic storage modulus (G′), loss modulus (G′′), and complex viscosity (η*) than that of pure PVC, and these values reached maximum for the blend with 10 wt% ACS. When ACS content was below 10 wt%, PVC and ACS showed good compatibility in the blends by displaying a single T _g; however, when ACS content was more than 15 wt%, the phase separation phenomena occurred in the blends. PVC/ACS blends showed larger storage modulus (E′) and loss modulus (E′′) than that of pure PVC, but these values decreased with increasing ACS content. ACS can enhance both tensile and impact strength of PVC, and the impact strength reached maximum with 15 wt% ACS content which is higher 2.5 kJ/m² than the pure PVC. These results suggested that ACS is an efficient processing aid and toughening modifier for PVC at appropriate content.     

Enhancing mechanical and shape memory properties of polylactide/polyamide elastomer blends via reactive blending with a chain extender

The structure and properties of incompatible polylactide (PLA)/polyamide elastomer (PAE) blends were tailored by a chain extender specifically the styrene–glycidyl acrylate copolymer Joncryl ADR4368 (ADR). Various PLA/PAE/ADR blends with different compositions were prepared by melt blending, and their morphology, crystallization behavior, and mechanical and the shape memory properties were systematically investigated. The results showed a uniform dispersion of PAE particles in the PLA matrix for the PLA blends with a reduction in particle size upon the addition of ADR. The crystallization of PLA was retarded, which was confirmed by a decrease in the melt crystallization temperature and an increase in cold crystallization temperature in the PLA/PAE/ADR blends. Rheological analysis showed an improvement in the melt elasticity of the PLA/PAE binary blend due to the presence of ADR, possibly attributed to the formation of long-chain-branched copolymers at the interface. Notably, the PLA/PAE/ADR blend exhibited superior toughness, featuring an elongation at break of 288% and a notched impact strength of 37 kJ·m⁻², along with a high shape memory fixation rate and recovery rate when the ADR content was 1 wt%. Furthermore, the underlying toughening mechanism was elucidated. This work may offer an industrially scalable relevant model to fabricate high-performance PLA materials.     

Performance evaluation of polyvinylchloride/polyacrylonitrile ultrafiltration blend membrane

Polyvinylchloride (PVC) membranes were modified by blending with polyacrylonitrile (PAN) as a second polymer. The miscibility of PVC/PAN blend was examined using an incompressible regular solution (CRS) model in no need to make a membrane. The results showed that the PVC/PAN blend was immiscible for all compositions at a temperature range of ?25 to 225 °C. Furthermore, the prediction of the phase behavior of a PVC/PAN/DMF ternary system showed that the blend of two polymers was highly incompatible even in their common DMF solvent. However, this incompatibility led to a remarkable increase in the porosity of the blend membrane and pure water flux compared to those for pure PVC membrane. The pure water flux of the PVC membrane (37.9 ± 1.5 L/m² h) increased about 41 and 76% by adding 10 and 20 wt% PAN, respectively. The blend membranes also showed an enhanced flux recovery ratio (FRR) compared to a pure PVC membrane, although the PVC membrane rejection for Bovine serum albumin (BSA) was decreased after blending with PAN. The PVC/PAN (90/10) blend membrane was subjected to hydrolysis with NaOH alkaline solution at three different concentrations and contact times to further enhance its performance. The membrane, which was hydrolyzed with a 0.5 mol/L NaOH solution for 0.5 h, showed a highest pure water flux of 75.6 ± 7.2 L/m² h due to its increased hydrophilicity. This membrane also revealed an improved FRR and better thermal and mechanical properties compared to an unmodified membrane.     

PVC/PVDF/CPE共混体系研究

以ＣＰＥ作为ＰＶＣ／ＰＶＤＦ的增容剂,研究了ＰＶＣ／ＰＶＤＦ／ＣＰＥ三元共混新体系。对不同组成的共混物的物理机械性能进行测试,分析了讨论了ＰＶＤＦ／ＣＰＥ的增韧效果和机理。结果表明：ＣＰＥ对ＰＶＣ／ＰＶＤＦ共混体系有明显的增容作用,ＰＶＤＦ／ＣＰＥ并用对增韧ＰＶＣ有显著的协同效应。