Functionalization of polyethylene surface using plasma-induced graft copolymerization of acrylic acid

Plasma-induced graft copolymerization of acrylic acid onto PE films was investigated. The influence of plasma treatment power, pressure, time, graft copolymerization time, and monomer concentration on polymerization yield was determined. A chemical shift of the Cls signal of Ar plasma treated and untreated PE films was revealed by ESCA, which also verified the presence of grafted PAAc. An increase in graft polymerization yield with plasma treatment time and power was found. Both the plasma treated film and the subsequently grafted film were shown to be hydrophilic. Only the grafted film, however, shows an invariably low contact angle. The decomposition of peroxides upon heating was followed by a simple first-order reaction. © 1993 John Wiley & Sons, Inc.     

Preparation and characterization of a homobifunctional silicone rubber membrane grafted with acrylic acid via plasma-induced graft copolymerization

Polyacrylic acid (PAA) was grafted onto the surface of silicone rubber membrane (SR) by plasma-induced graft copolymerization (PIP). Ar-plasma was used to activate the surface of SR. Also, a determination was made of the influences of plasma treatment power, pressure, time, grafted copolymerization reaction time, and monomer concentration on polymerization yield. The surface properties of SR were measured by ATR-FTIR, ESCA, and SIMS. In those analyses, the elemental composition and different carbon bindings on the surface of SR were examined by ESCA with the amount of O1s/C1s being approximately 0.7 at 60 s by Ar-plasma treatment (60 W, 200 mtorr). The peroxide group introduced on SR was measured via 1,1-diphenyl-2-picryhydrazyl (DPPH). The optimum amount of peroxide groups was 6.85 × 10⁻⁸ mol/cm² at 60 s of Ar-plasma treatment. The peroxide group (33D peak) was introduced onto the surface of SR by negative spectra of SIMS analysis after SR treatment by Ar-plasma. An increase was obtained in grafted polymerization yield with a region of 5 to 50% (v/v) of acrylic acid aqueous solution. Both sites of polyacrylic acid were detected after staining by toluidine blue O. That is, a homobifunctional membrane was developed via this surface modification method. © 1996 John Wiley & Sons, Inc.     

微波等离子体诱导聚乙烯表面接枝甲基丙烯酸甲酯

聚乙烯（ＰＥ）通常作为性能优良的薄膜材料被广泛使用,但由于其表面能低,导致表面亲水性差,粘结性弱,染色性能、印刷性能等很不理想［１,２］．在高分子材料的各种表面改性方法中,接枝共聚是一种很有效的途径［３～５］．本文探讨了用微波冷等离子体激活聚乙烯表面...     

Oxidation of polyethylene surface by corona discharge and the subsequent graft polymerization

Oxidation of a polyethylene (PE) surface by corona discharge and the subsequent graft polymerization of acrylamide (AAm) were studied. The maximum amount of peroxides introduced by corona treatment at a voltage of 15 kV was about 2.3 × 10^?9 mol cm^?2. The decomposition rate of peroxide and the dependence of graft amount on the storage period of the corona-treated PE films showed that there were several kinds of peroxides, the labile one being mainly responsible for the initiation of graft polymerization. When the corona-treated film was brought into contact with a deaerated aqueous solution of AAm, graft polymerization took place more strongly with the treatment time, but was reduced after passing a maximum. Although the x-ray photoelectron spectroscopic analyses of the corona-treated PE films showed homogeneous oxidation of the outer polymer surface by corona discharge, optical microscopy on the cross section of the grafted film revealed the graft polymerization to be limited to a very thin surface region.     

Excellent anti‐bacterial activity and surface properties of polyamide‐6 films modified with argon‐plasma and methyl diallyl ammonium salt‐graft

In this study, the effect of argon‐plasma treatment on the grafting of methyl diallyl ammonium salt (MDAA) onto polyamide‐6 film and the anti‐bacterial and surface properties of the plasma‐ and graft‐treated film were investigated. The grafting amounts of MDAA caused by argon‐plasma treatment increased with the increase in the plasma exposure time and plasma power. The analyses of Fourier transform infrared (FT‐IR) spectroscopy and electron spectroscopy for chemical analysis (ESCA) spectra revealed that the epoxy and vinyl groups of MDAA could be grafted on the argon‐plasma treated polyamide‐6 film. The survey spectra of ESCA, the patterns of atomic force microscopy (AFM), and the spectra from scanning electron microscopy (SEM) were employed to certify the surface modification of argon‐plasma treated and the argon‐plasma treated/MDAA grafted polyamide‐6 films. Argon‐plasma treatment could generate the functional group and increase the roughness on the surface of polyamide‐6 film. This phenomenon could enhance the grafting effect of MDAA. The anti‐bacterial property of argon‐plasma treated/MDAA grafted polyamide‐6 film was excellent. This argon‐plasma treated/MDAA grafted polyamide‐6 film was expected to be applied on the field of packing. Copyright © 2008 John Wiley & Sons, Ltd.     

预氧化聚烯烃膜的表面光接枝聚合

将经表面热氧化的聚丙烯和聚乙烯膜在不加敏化剂的情况下,通过紫外光照射与光稳定剂甲基丙烯酸(2,2,6,6-四甲基哌啶)酯进行接枝聚合,以改善膜的光稳定性。研究了各种因素,包括热氧化时间,光照射时间、单体浓度及溶剂等对表面预氧化膜的光接枝含量的影响。实验结果表明,常用的有机溶剂除酮类外均不能使膜接枝;接枝以后膜的光稳定性有很大的提高。     

GRAFTING OF PEROXIDE-INITIATED MALEIC ANHYDRIDE ON SPHERICAL PE／PP IN-REACTOR BLEND GRANULES

Spherical polyethylene/polypropylene (PE/PP) in-reactor blend granules with various ethylene/propylene molar ratios and high porosity were synthesized using a high yield TiCl4/MgCl2 supported catalyst. A solution of benzoyl peroxide (BPO)/maleic anhydride (MAH)/xylene (interfacial reagent) or BPO/MAH/St (comonomer) was absorbed onto the PE/PP inreactor blend granules, and solid phase gratt polymerization of MAH on PE/PP was conducted. The amount of grafted MAH on PE/PP was measured through chemical titration. The results showed that solid phase graft polymerization of MAH in PE/PP in-reactor blend granules produced graft copolymer with high amount of grafted MAH, and the amount of grafted MAH was raised slightly when St was introduced as comonomer. The graft in-reactor blend was fractionated into five fractions through temperature-gradient extraction fractionation (TGEF), and the fractions were analyzed by FTIR. The results revealed that MAH is mainly grafted on the PE segments, whereas MAH was predominantly grafted on the PP segments when St was present in the graft polymerization system. In addition, the final product is still in the form of regular spherical granules, which is beneficial for industrial processing.     

Immobilization of poly(ethylene oxide) on polyethylene using a plasma-induced graft copolymerization process

A radio-frequency glow discharge induced graft copolymerization process has prepared a PAAc-grafted PE film in this present study. Poly(ethylene oxide) (PEO) was then covalently immobilized onto PAAc-grafted PE film by a chemical coupling reaction. Carboxylic groups were introduced onto the surface of PE film by exposing the film to an Ar plasma, and the plasma-treated film was then next reacted with a 50% acrylic acid aqueous solution. These functional groups were reacted with bisamino PEO by a coupling agent CMC. ESCA, IR, and water contact angle studies were conducted for characterizing the surfaces of these films during the varied stages of the reaction. Increasing the molecular weight of the PEO attached to the PAAc-grafted PE resulted in an increased wettability of the films. © 1993 John Wiley & Sons, Inc.     

等离子体引发聚丙烯接技苯乙烯共聚物的合成及性能

将等离子体接枝技术用于聚丙烯接枝苯乙烯共聚物的合成．ＦＴ ＩＲ、ＳＥＭ及ＸＰＳ证明所得产物为接枝共聚物．研究了不同等离子体处理体系压强、处理功率，反应瓶不同直径、体积，不同接枝聚合反应时间、温度对接枝率的影响．利用接枝共聚物制备了硫酸钠型离子交换膜，并对其电性能进行了初步探讨．     

Solvent effects on the synthesis of ion-exchange membranes by radiation-induced graft polymerization of methyl α,β,β-trifluoroacrylate

Methyl α,β,β-trifluoroacrylate (MTFA) was grafted onto polyethylene (PE) film and fluorine-containing films to make ion-exchange membranes. In the case of PE the grafting yield was not influenced by the presence of trifluorotrichloroethane (Freon 113) in the reaction mixture, while the presence of methanol decreased the grafting yield. The transversal distribution of graft chains in the film observed by electron-probe x-ray microanalysis showed that when the grafting was carried out in the presence of Freon the amount of graft chains in the central part of PE film was much larger than that at the film surface and that the grafts obtained in the absence of Freon were located mainly at the film surface. The electric resistance of the graft PE film obtained in the presence of Freon decreased more than that of the one obtained in the absence of Freon. The weight loss of the graft films in H₂O₂ solution was negligibly small.     

接枝丙烯酰胺改善聚乙烯膜表面亲水性的研究

利用等离子体技术和紫外照射接枝相结合在聚乙烯膜表面接枝丙烯酰胺(AAm)以改善其亲水性。通过衰减全反射红外光谱(ATR-FTIR)、X射线光电子能谱(XPS)和接触角测定验证了在无光引发剂的条件下,将等离子体预处理和紫外照射接枝结合起来可以有效地提高AAm的接枝效果,很好地改善PE膜表面的亲水性。探讨了等离子体复合参数W/(FM)、等离子体预处理时间、AAm单体浓度以及紫外照射时间对改善PE膜表面亲水性的影响,确定改善PE膜表面亲水性的最佳实验条件。     

ESCA and optical emission study of the inductively coupled RF plasma copolymerization of naphthalene and octafluoronaphthalene mixtures

Plasma polymerization of octafluoronaphthalene, naphthalene, and 1 : 1 mixtures of the two yielded thin films which were then analyzed by ESCA. Optical emission was recorded during deposition and the resultant spectra are shown. Deposition of the copolymer at 150°C resulted in a film whose composition was different from that deposited at room temperature and from the single plasma polymers. Copolymerization resulted in a lowering of CF₂ functionalities and an increased retention of the aromatic nature of the monomers. Optical emission of CF₂ during copolymerization was greatly reduced as was a peak at about 510 nm.     

聚丙烯表面接枝PNIPAAm膜Ⅰ.光接枝反应和表面形态结构研究

以氧杂蒽酮或二苯甲酮为引发剂 ,通过紫外光引发表面接枝聚合的方法在聚丙烯薄膜表面引入了具有温度敏感特性的聚异丙基丙烯酰胺 (PNIPAAm)接枝聚合物层 .提高紫外光强度和接枝反应温度均有利于接枝率增大 ,而单体浓度对接枝率的影响存在最佳值 ,为 0 1 8mol L .在引发剂预浸渍引发接枝和休眠基引发接枝这两种方式中 ,后者能够实现更高的接枝率 .红外光谱 (FTIR)、X射线光电子能谱化学分析 (ESCA)和扫描电子显微镜 (SEM)等对接枝层组成的表征结果证实了接枝层的存在 .在不同温度下 ,接枝膜的FTIR谱图中酰胺I带和酰胺II带特征吸收峰发生位移 ,表明它具有温度敏感特性 .同时 ,SEM研究发现由于接枝膜的温度敏感特性而导致的球状表面形态结构     

Plasma fluorination of polyolefins

ESCA and contact angle measurements were used to characterize the surfaces of Polyethylene and polypropylene films exposed to SF₆, CF₄, and C₂F₆ plasmas. None of these gases polymerized in the plasma. However, all plasma treatments grafted fluorinated functionalities directly to the polymer surfaces. SF₆ plasmas graft fluorine atoms to a polyolefin surface. CF₄ plasmas also react by a mechanism dominated by fluorine atoms, but with some contribution from CF_x-radical reactions. Although C₂F₆ does not polymerize, the mechanism of grafting is still dominated by the reactions of CF_x radicals. For all gases studied, the lack of polymerization is attributed to competitive ablation and polymerization reactions occurring under conditions of ion bombardment.     

Functionalization of Poly[Ethylene Terephthalate) by Means of Glow-Discharge-Initiated Polymerization of Acrylic Acid

Glow-discharge-initiated polymerization of acrylic acid incorporated in poly(ethylene terephthalate) (PET) films was investigated. An increase in polymerization yield with plasma treatment duration and power was found. Polymerization was not confined to the film surface. At high power and long treatment time, polymerization in the bulk of the PET also took place. Water regain and contact angle of the PET-treated films were affected by the presence of poly(acrylic acid) (PAA). The carboxyl groups of the PAA chains incorporated in the PET matrix were utilized for further chemical modification of the PET film. Poly(ethylene glycol) (PEG) was grafted onto PAA by esterification. DSC studies showed the presence of both PAA and PEG in the PET matrix and shed light on the morphology of the multicomponent polymeric system. Free isocyanate groups were introduced into the PET matrix by reacting PAA carboxyl groups with hexamethylene diisocyanate.     

聚乙烯表面接枝聚合改性及抗凝血性的研究

聚乙烯(PE)膜经Ar等离子体预处理,无光引发剂紫外光照接枝甲基丙烯酸缩水甘油酯(GMA),然后进行肝素化处理,以改善PE的抗凝血性能。用正交实验确定接枝反应的最优条件。通过X-射线光电子能谱(XPS)、衰减全反射红外光谱(ATR-FTIR)、扫描电子显微镜(SEM)和接触角测定PE膜接枝GMA前后表面性能和表面形貌。用复钙时间、凝血酶原时间、部分凝血活酶时间、凝血酶时间和血小板粘附实验对其抗凝血性能进行评价,结果表明,被修饰PE膜的抗凝血性能显著提高。     

Evidence and mechanisms of filling polymerization by plasma-induced graft polymerization

Using a plasma-induced graft polymerization technique, which is well known as a surface modification method, the grafted polymer was formed in pores of the porous material. This study examined the filling mechanism. Five thin porous films were sandwiched together, and employed as the substrate. The substrate was treated by plasma, and the change in surface tension and radical formation was measured for each sheet after the sheet was separated. The only surface on which surface-tension change was detected, was that of the sheet directly exposed to the plasma. Although plasma treatment made polymer radicals primarily on the outer surface of the sheet, the treatment also formed a few radicals inside the sheets. The radicals inside the sheets reacted with methylacrylate and grafted polymer formed in the pores. The location of grafted polymer depended on the balance between monomer diffusivity and reactivity. The grafting rate depended on which monomer solvent was used for the polymerization. Thus, the grafted membrane morphology could be controlled by varying the grating solvent composition. © 1996 John Wiley & Sons, Inc.     

紫外光引发LDPE膜接枝含氟丙烯酸酯的研究

通过紫外光引发表面接枝聚合反应的方法 ,把含氟丙烯酸酯单体R 5 6 1 0引到LDPE薄膜上 .对经丁酮抽提后的接枝膜进行FTIR、ESCA、SEM和DSC等表征 ,证实含氟聚合物以化学键的方式接枝在LDPE基体膜上 .在一定范围内 ,增加紫外光强、引发剂和单体浓度以及反应温度等均有利于提高接枝率 .经计算R 5 6 1 0的紫外光引发接枝聚合反应总活化能为 5 4 2kJ mol.接枝膜的接触角随着接枝率的提高逐步增大 ,直至趋于恒定 .作者提出接枝膜存在一个在接触角测定时影响基体膜与探测水滴相互作用过程的边界层 .当接枝率较低、接枝层厚度小于边界层临界厚度时 ,基体LDPE影响接触角的大小 ,但随着接枝率提高 ,接枝层逐渐变厚 ,氟聚合物层对接触角的贡献逐渐占优势 ,导致接触角随之增大 .当接枝率超过一定值以后 ,接枝层厚度超过边界层临界厚度 ,接枝层对接枝膜的接触角起全部贡献 ,接触角测定值随之稳定     

Preparation and characterization of functional group gradient surfaces

Functional group gradient surfaces where the density of functional groups changes gradually along the sample length were prepared. The functional group (? COOH, ? CONH₂, and ? OH group) gradient surfaces were produced by the treatment of low-density PE sheets using a corona with gradually increasing power, followed by the graft copolymerization of acrylic acid and subsequent substitution reaction of carboxylic acid groups to amide or hydroxyl groups. The prepared gradient surfaces were characterized by the measurement of water contact angle, FTIR-ATR, and ESCA. The gradient surfaces prepared can be used to systematically investigate the interactions of biological or other species in terms of the surface functional groups and their density of polymeric materials. © 1994 John Wiley & Sons, Inc.     

原生态聚丙烯等离子体处理接枝甲基丙烯酸甲酯

将等离子体接枝技术，用于原生态聚丙烯接枝甲基丙烯酸甲酯共聚物的合成。ＦＴ－ＩＲ证明所得产物为接枝共聚物，研究了不同等离子体处理功率、时间，不同接枝聚合反应时间、温度对接枝的影响，以及稀释剂、聚丙烯粒度对接枝的影响。结果表明，接枝过程中有自动加速现象，稀释剂亦使接枝有加速效应。接枝过程为扩散控制过程。