聚四氟乙烯微粉的表面改性及其在橡胶中应用的研究进展

聚四氟乙烯(PTFE)微粉具有良好的综合性能,经常用作材料的改性添加剂。本文首先介绍了PTFE微粉表面改性所采用的辐照处理法、等离子体处理法、化学溶液处理法、高温熔融法和种子乳液聚合法的特点,表面改性可改善PTFE微粉与其他材料共混时分散不均匀、相容性差的缺点,然后阐述了PTFE微粉在氟橡胶、丁腈橡胶、丁苯橡胶、乙丙橡胶、硅橡胶、丁基橡胶和天然橡胶中的应用研究进展。     

聚四氟乙烯表面改性的研究进展

综述了国内外聚四氟乙烯(PTFE)表面改性的研究进展,主要介绍了改性技术(如钠-萘络合物化学改性、高温熔融改性、高能辐射接枝改性、准分子激光处理、离子束注入改性和低温等离子体改性等)在PTFE表面改性方面的应用情况,简要叙述了各种改性方法的优势与不足,并由此提出了PTFE表面改性的发展趋势。     

有机材料改性PTFE的研究进展

聚四氟乙烯(PTFE)由于具有优异的特性受到了广泛关注,但是其仍存在缺陷,需要通过对其进行改性,提升其复合材料的性能。研究表明,加入有机材料能显著改善PTFE的性能。概述了采用有机材料表面改性、填充改性和共混改性3种方法改性聚四氟乙烯(PTFE)复合材料的研究现状,即分别采用表面改性的钠-萘溶液方法、填充改性的聚苯酯(POB)、聚酰亚胺(PI)、聚苯烯腈(PAN)和聚酰胺(PA)以及共混改性的聚醚醚酮(PEEK)、聚苯硫醚(PPS)和聚甲醛(POM)改性PTFE的研究进展,重点解决了PTFE的高磨损问题,提升了复合材料的耐磨性能,并且分析了其增强机理。最后,对利用有机材料改性PTFE复合材料的研究进行了总结与展望。     

碳纤维表面改性技术研究进展

从涂层改性(包括上浆与涂覆、液相沉积、气相沉积、火焰法),氧化改性(包括气相氧化、液相氧化、电化学阳极氧化)和聚合改性(包括化学聚合、电化学聚合、等离子聚合、辐照辅助聚合)等方面,列举了目前常见的碳纤维表面改性方法.分别介绍了上述各处理方法的原理及其优缺点,并指出了现有改性研究均为对碳纤维表面化学状态或物理形貌的单方面...     

聚酰亚胺胶粘剂改性技术研究进展

介绍了近年来聚酰亚胺(PI)胶粘剂的常见改性方法。重点分析和总结了PI胶膜表面化学改性方法(包括等离子体改性、离子束改性、化学试剂改性和表面接枝聚合改性等)和PI胶粘剂材料化学改性方法,并对PI胶粘剂改性技术的未来发展趋势进行了展望。     

纳米氧化锌的制备和表面改性技术进展

综述了化学沉淀法、醇盐水解法、微乳液法、固相合成法、溶胶 凝胶法和喷雾热解法的主要特点与优缺点,并对纳米氧化锌的表面改性方法:即表面包覆改性法、表面化学改性法、机械力化学改性法、沉淀反应改性法、外膜层改性(胶囊)法和高能表面改性法进行了概述。     

聚四氟乙烯膜亲水改性及在工业污水处理中的应用进展

聚四氟乙烯(PTFE)膜因化学性能稳定、耐高温、耐酸碱等特点被广泛应用在化工、纺织、环境、食品等领域。然而,由于PTFE材料的强疏水性和极低表面能,使得PTFE膜润湿性差,难以处理水性溶液,限制了其应用。对近年来常用的钠-萘溶液处理、等离子体接枝、多巴胺改性、表面活性剂改性等PTFE膜亲水改性方法进行了综述。相关研究表明,亲水改性后的PTFE膜可以用于污水处理、膜蒸馏、膜生物反应器等领域。最后对PTFE膜亲水改性的发展趋势进行了展望。     

聚四氟乙烯表面改性技术研究进展

综述了国内外聚四氟乙烯(PTFE)表面改性技术的研究进展,主要介绍了准分子激光改性、高能辐射改性、化学改性、高温熔融改性、等离子体改性及离子束注入改性等在PTFE表面改性方面的应用情况,简要叙述了各种改性方法的优势与不足,并对PTFE表面改性的发展趋势进行了展望。     

硅灰石纤维改性PTFE材料摩擦性研究

采用硅灰石纤维(WF)、青铜粉、石墨填充改性聚四氟乙烯(PTFE),制备了PTFE摩擦材料。结果表明,与用作密封件的传统改性PTFE材料相比,采用WF、青铜粉与石墨复合改性的PTFE材料,具有较好的抗磨损性能,对对磨材料损伤较轻微,具有较好的硬度,能用作长期使用的密封材料。     

纳米氧化镁粉体表面改性技术的研究进展

简述了纳米氧化镁表面改性的原因,并对纳米氧化镁的表面改性方法(物理改性和化学改性法):即表面包覆改性法、表面化学改性法、机械力化学改性法、沉淀反应改性法、外膜层改性(胶囊)法、和高能表面改性法进行了概述.着重介绍了表面活性剂、偶联剂在纳米氧化镁表面改性方面的应用,并对纳米氧化镁改性方面的研究提出了建议.     

Processing and characterization of multilayer films of poly(ethylene terephthalate) and surface-modified poly(tetrafluoroethylene)

Multilayer films were prepared from poly(tetrafluoroethylene) (PTFE) and poly(ethylene terephthalate) (PET) films together with using an adhesion promoting layer (tie-layer) consisting of ethylene-methyl acrylate-glycidyl methacrylate (E-MA-GMA) terpolymer and low density polyethylene (LDPE) blend. Na/naphthalene treatment and subsequent acrylic acid grafting were applied on the surfaces of PTFE for chemical modification. FT-IR spectroscopy, XPS analysis and surface energy measurements were performed to characterize the modified PTFE films. The analyses showed defluorination and oxidation of PTFE surface, and supported the acrylic acid grafting. The surface energy of modified surfaces enhanced with respect to unmodified one, which promoted adhesion. The multilayers were subjected to T-peel tests to measure the adhesion strength between PET and modified PTFE. Peel strength between the films increased with increasing E-MA-GMA amount in the tie-layer. A proportional dependence of peel strength on Na/naphthalene treatment time was observed for multilayers containing acrylic acid grafted or ungrafted PTFE. From SEM analysis, it was observed that the texture of the PTFE surface after modifications became rougher when compared to untreated PTFE. The peeled surfaces were also analyzed by SEM. The micrographs evidence that the energy absorbing mechanism is the plastic deformation of the tie-layer, which is responsible for obtaining high peel strengths.     

聚四氟乙烯表面亲水改性研究进展

综述了国内外聚四氟乙烯(PTFE)表面亲水改性的研究进展,主要介绍了湿化学处理、低温等离子、辐射接枝、激光处理等方法在PTFE表面改性方面的应用情况,简要叙述了各改性方法的优缺点,并对PTFE表面改性的发展前景进行了展望.     

Surface grafting polymerization and modification on poly(tetrafluoroethylene) films by means of ozone treatment

Surface modification on polytetrafluoroethylene (PTFE) films was performed with sequential hydrogen plasma/ozone treatments and surface-initiated polymerization. C-H groups were introduced to the surface of PTFE films through defluorination and hydrogenation reactions under hydrogen plasma treatment. The C-H groups then served as ozone accessible sites to form peroxide groups under ozone treatment. Grafting polymerization initiating from the peroxide groups was performed on the PTFE film surface with using acrylamide, acrylic acid, glycidyl methacrylate and 2-(2-bromoisobutyryloxy)ethyl acrylate (BIEA) as monomers. With utilizing the isobutylbromide groups on the surface of PTFE-g-PBIEA film as initiators, sodium 4-styrenesulfonate (NaSS) was polymerized onto the PTFE film surface via atom transfer radical polymerization, to bring arborescent macromolecular structure to PTFE film surface. The chemical structures of the macromolecules on PTFE film surfaces were characterized with FTIR-ATR, SEM-EDX and XPS. The surface hydrophilicities of modified PTFE films were significantly enhanced with the modification.     

Surface modification of poly(tetrafluoroethylene) film by plasma graft polymerization of sodium vinylsulfonate

Poly(tetrafluoroethylene) (PTFE) surface was modified by the graft polymerization of sodium vinylsulfonate, and the chemical composition of the graft-polymerized PTFE surface was analyzed by X-ray photoelectron spectroscopy. Peroxides were formed on the PTFE surface by a combination procedure of argon plasma irradiation and air exposure, and the graft polymerization of sodium vinylsulfonate was initiated by the peroxide groups at 65–80°C. The peroxide concentration is 3 × 10⁺¹³ to 5 × 10⁺¹³ numbers/cm². The average degree of polymerization of the graft polymers was 3.4 × 10³. The graft polymer is distributed over the PTFE surface, but part of the PTFE surface remains uncovered. The coverage with the graft polymer is 43%. The PTFE surface graft polymerized with sodium vinylsulfonate was somewhat hydrophilic, but the hydrophilicity was lower than that of the PTFE surface modified by plasma treatment. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 77–84, 1997     

Growth of muscle cells on plasma-treated and gold nanoparticles-grafted polytetrafluoroethylene

Polytetrafluoroethylene (PTFE) was modified by Ar plasma with different exposure times. The plasma-activated surface was immersed in biphenyldithiol and subsequently in colloidal solution of Au nanoparticles. The changes in the surface wettability contact angle were examined by goniometry. Atomic force microscopy was used to determine the surface roughness and morphology. Changes in the chemical structure of the modified PTFE were studied using X-ray photoelectron spectroscopy (XPS) and electrokinetic analysis. The interaction of plasma-treated and grafted samples with vascular smooth muscle cell derived from the rat aorta was also studied. Specifically, the number and morphology of the adhered and proliferated cells on the PTFE were studied under in vitro conditions. The plasma treatment and the subsequent biphenyldithiol and Au nanoparticles grafting led to changes in the polymer surface chemistry, morphology, roughness and wettability. The polymer grafting with biphenyl-4,4′-dithiol (BFD) and subsequently with Au nanoparticles led to a decrease in the surface polarity. XPS measurements proved the presence of S and Au on the PTFE surface. Grafting with BFD and Au nanoparticles led to the decrease in surface roughness. In comparison with the pristine polymer, the plasma treatment and Au nanoparticles grafting increased the adhesion and proliferation of vascular smooth muscle cell.     

聚四氟乙烯表面处理方法综述

从聚四氟乙烯的表面性能出发，研究其性能特点，进而介绍了化学处理、高温熔融、辐射接枝、等离子体、电解还原以及激光处理等聚四氟乙烯的各种表面处理方法。最后指出正是因为这些处理方法的不同，才为聚四氟乙烯的改性提供了更多的途径。     

等离子体预处理聚四氟乙烯接枝改性提高粘接性能的研究进展

由于碳氟原子间强烈的结合力和氟原子的保护作用,使聚四氟乙烯(PTFE)具有优异的耐高温性能和极强的化学惰性,故其在苛刻环境中得到广泛应用。为了提高PTFE与其他物质的粘接性能,必须对其进行接枝改性。详细介绍了等离子体预处理PTFE的接枝改性技术,包括改性方法的特点、影响因素、接枝后的表征和应用情况等。     

Surface modification of PTFE by 60Co γ-ray irradiation

Surface carboxyl groups were formed during the ⁶⁰Co γ-ray irradiation of poly(tetrafluoroethylene) (PTFE) in air. Fourier transform infrared spectroscopy enables the detection of surface carboxyl groups. The contact angles were used to calculate the dispersive and polar components of the surface free energy according to a two-liquid method. The γ-ray irradiation of PTFE mainly caused degradation of the polymer. The concentration of carboxyl groups, the wettability, the friction, and the dispersive and polar components of the surface energy and the crystallinity on PTFE surface were increased, while the particle size of PTFE decreased with increasing irradiation dose. A highly modified PTFE was used to reduce the aqueous liquid repellent properties of PTFE. A 20 kGy dose for modified PTFE surface was suitable in air additivity in antifriction, anticorrosion, antifouling, lubrication, and noise reduction coatings. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 435–441, 1998     

Preparation and characterizations of organic fluorine–silicon and polytetrafluoroethylene modified polyester

Hydrophobically modified polyester was synthesized via copolymerization between hydroxy‐fluorosilicone polymer (FGX) and bis(2‐hydroxyethyl) terephthalate (BHET), which was named as CMPET. The relations between surface properties of CMPET and FGX viscosity and dosage were studied by contact angle measurements. An optimized synthesis route was determined. b‐CMPET with better hydrophobic property was obtained by adding polytetrafluoroethylene (PTFE) into CMPET. A full characterization were given to both CMPET and b‐CMPET, including ¹H‐NMR, ESCA, mechanical properties, water absorption, contact angle and surface energy analysis. It was found that chemical bondings were formed between FGX and BHET in c‐CMPET via copolymerization. The addition of 12% FGX with viscosity of 2000CP after the system pressure reached the low pressure for 20 min is an optimum condition. The modified polyester (CMPET‐12) shows the best hydrophobic effect. Blending a certain amount of PTFE powder with low‐surface energy can further enhance the hydrophobic properties of CMPET, due to a strong tendency of PTFE migrate to the sample surface together with organic fluorine–silicon segments. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Modification of poly(tetrafluoroethylene) and gold surfaces by thermal graft copolymerization for adhesion improvement

The adhesion between a poly(tetrafluoroethylene) (PTFE) film and a gold substrate was achieved by surface graft copolymerization of glycidyl methacrylate (GMA) on an argon plasma-pretreated PTFE film at elevated temperature with simultaneous lamination to a surface-modified gold substrate. The plasma pretreatment introduces peroxides which are thermally degraded into radicals to initiate the graft copolymerization of GMA on the PTFE surface. The gold surface, on the other hand, was first pretreated with 3-mercaptopropionic acid (MPA), 3-mercaptopropionic acid-2-ethylhexyl ester (MPAEE), or (3-mercaptopropyl)trimethoxysilane (MPTMS) to form self-assembled monolayers (SAMs) and then subjected to Ar plasma treatment. The simultaneous graft copolymerization and lamination of the PTFE film to the gold surface was carried out in the presence of GMA and an amine hardener at an elevated temperature under atmospheric conditions. The modified surfaces and interfaces were characterized by X-ray photoelectron spectroscopy (XPS) and contact angle measurements. The gold/GMA/PTFE assembly exhibited a T-peel adhesion strength above 10 N/cm and the joint delaminated by cohesive failure inside the bulk of the PTFE film. The strong adhesion of the Au/PTFE laminate is the result of concurrent graft copolymerization on both the Ar plasma-pretreated PTFE surface and the SAM of the Au surface to form a covalent network. The network is further strengthened by the crosslinking reaction promoted by the presence of the hardener.