Surface grafting polymerization of vinyl monomers on poly(tetrafluoroethylene) films by plasma treatment

Poly(tetrafluoroethylene) films were surface modified by argon plasma treatment followed by graft polymerization. Peroxidе groups were introduced on the surface of poly(tetrafluoroethylene) films after plasma treatment and the consequent contact with air when the films were taken out of the reactor. Grafting polymerization initiated by the surface peroxide (hydroxide) groups was performed on the poly(tetrafluoroethylene) film surface by using acrylic acid, 4-vinylpyridine and 1-vinylimidazole as monomers. Copolymers were obtained with grafting yield from 0.436 to 0.457 mg/cm² for poly(acrylic acid), from 0.299 to 0.390 mg/cm² for poly(4-vinylpyridine) and from 0.212 to 0.256 mg/cm² for poly(1-vinylimidazole), respectively. The free surface energies of the copolymers were determined. The chemical structures and the copolymer surfaces were characterized by IR, XPS and SEM analyses. High energy resolution X-ray photoelectron spectroscopy (XPS) confirmed the grafting of acrylic acid, 4-vinylpyridine and 1-vinylimidazole. The surface hydrophilicities of modified polytetrafluoroethylene films were significantly enhanced after plasma treatment and grafting modification. It is worth emphasizing that in this work acrylic acid, 4-vinylpyridine and 1-vinylimidazole were used as the reactive monomers for grafting on the poly(tetrafluoroethylene) film by plasma treatment. We believe that this vinyl monomers may be employable as functional groups, permitting a potentially wide range of applications: as ionomers, membranes, carriers for immobilization of biomolecules, for complex formation with heavy metals as catalysts.     

用低温等离子体诱导PET织物接枝丙烯酸

运用氧气等离子体表面改性技术对PET织物进行处理后接枝丙烯酸,探讨了处理时放电功率、单体浓度、反应温度、处理时间等对接枝率的影响,并对接枝率与织物的吸湿性进行了研究。     

低温氨等离子体改性聚醚砜超滤膜气相接枝丙烯酸

采用低温氨等离子体处理和气相接枝丙烯酸对聚醚砜(PES)膜进行表面改性,以提高超滤膜亲水性和抗污染能力。考察了改性膜物理及化学特性变化,并研究了改性膜的通量及截留率特性。结果表明,改性膜表面接枝有亲水基团,水接触角由原始的67°降低至9°,亲水性能明显提高;纯水通量、牛血清蛋白通量和截留率均大于原始膜。     

Graft polymerization of acrylic acid onto polypropylene monofilament by RF plasma

Plasma‐induced graft polymerization of acrylic acid onto polypropylene monofilament was carried out to introduce carboxyl groups on its surface. The monofilament was treated with oxygen plasma to create hydroperoxide groups and subsequent graft polymerization of acrylic acid on exposed filament was carried out. An increase in the plasma power led to higher graft levels. It was observed that the hydroperoxide build up on PP surface follows linear increase with the increase in the plasma treatment time only up to 180 s beyond which it slowed down significantly. The formation of oxygenated species was ascertained by X‐ray photoelectron spectroscopy, and the peroxide content was measured by the 2′‐diphenylpicrylhydrazyl (DPPH) estimation. The grafting was observed to be considerably influenced by the plasma exposure time, plasma power, reaction temperature, monomer concentration and the storage temperature. A maximum in the degree of grafting was observed at 40% monomer concentration beyond which grafting tended to decrease very fast. The grafting was also found to be maximum at 50°C followed by a sharp decrease, subsequently. The storage of the exposed filament at ?80°C led to the identical grafting all along the 16 days. However, the storage at 25°C showed significant reduction in the degree of grafting. The atomic force microscopy showed that surface morphology is transformed into a nonhomogeneous one after the plasma exposure, but tends to flatten out after the grafting process in the form of globular structures. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Adhesion improvement of polyester/aluminium interface by plasma polymerization pretreatments

Plasma polymerizations (PP) of acrylic acid (AA) and methacrylic acid (MAA) on polyester were used to improve the adhesion of the polyester/aluminium interface. It was found that this adhesion measured by the peel test method is 5-10 times higher than in the case of untreated polyester. Comparisons of the X-ray photoelectron spectroscopy (XPS) results obtained from the treated polyester, the untreated polyester and the reference spectra of poly(acrylic acid) cast from H₂O suggest that the observed adhesion improvement can be explained in terms of the formation of new functionalities at the polyester surface.     

Modification of polyester fabrics by in situ plasma or post-plasma polymerisation of acrylic acid

In order to increase the hydrophilicities, thereby to impart soil resistance and to improve dyeability, poly(ethylene terephatalate) (polyester) fabrics were treated in low-temperature plasmas. Two alternative modifications were applied. Fabrics were directly treated in acrylic acid plasma in one investigation, while in the other they were first treated in argon plasma and then immersed in an aqueous acrylic acid bath. The plasma conditions (i.e. exposure time and discharge power) were changed to control the extent of plasma surface modification in the first approach, while the acrylic acid content and the incubation time were changed in the second procedure. The wettability, and therefore the dyeability and soil repellency, of polyester fabrics was significantly improved by both methods. The second method resulted in better dyeability and soil repellency in contrast to lower surface wettability.     

等离子体引发丙烯酸聚合

采用等离子体引发丙烯酸水溶液聚合 ,得到具有高吸水性的交联聚合物。研究了后聚合时间 ,单体浓度和丙烯酸中和度对吸水倍率及单体转化率的影响。研究结果表明在等离子体引发下 ,丙烯酸很容易进行聚合 ,且得到的聚合物具有数百倍的吸水率     

Preparation of carboxylate groups-containing thin films by plasma polymerization

Summary Plasma polymerization in a mixture of acrylic acid and carbon dioxide (CO₂) gas was investigated. The polymer deposition rate in plasma polymerization of acrylic acid increased by admixing CO₂ gas, and polymers containing carboxyl groups were formed. The amount of carboxyl groups alterable to carboxylate anions by treating with 0.1 N KOH solution or NH₃ gas reached twice of that formed in plasma polymerization without CO₂ gas.     

氩等离子体处理聚四氟乙烯粘接性能研究

利用氩等离子体表面处理后再经丙烯酸化学接枝处理方法对聚四氟乙烯(PTFE)薄片表面进行改性,发现PTFE对水的润湿性明显改善,然后用环氧胶进行粘接,其粘接强度有较大提高。     

Bipolar nanofiltration membranes based on plasma modified microfilters

Track‐etched membranes were used as support for deposition of plasma polymerized layers and formation of bipolar nanofiltration membranes. The 75 KHz plasma reactor was applied for that purpose. Three kinds of monomers were plasma polymerized. They were as follows: n‐butylamine, allylamine, and acrylic acid. For each monomer, the best polymerization parameters were selected. It was determined that acrylic acid deposited at the highest rate, then deposited allyloamine and finally n‐butylamine. Among the electrodes, the grounded one offered more stable layer and can be used for plasma polymer deposition. The obtained membranes showed good rejection properties toward bivalent ions. It was shown that the sequence of deposited layers did not affect the separation properties. For some investigated membranes, rejection reached 50–80% value. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39790.     

Water-ethanol separation by pervaporation through plasma graft polymerized membranes

Water-ethanol permselective membranes were prepared through plasma graft polymerization of acrylic acid, methacrylic acid, and acrylamide onto porous polypropylene film. In these membranes, the functions of permseparation and mechanical properties are shared respectively to the graft polymer layer and the substrate film. Higher permselectivity of water is achieved with the ionization of the acrylic acid and the methacrylic acid-grafted membranes. Permselectivity is dependent on the degree of grafting, and it is necessary to fill the pores of substrate film with graft polymers. Permseparation of water was investigated with respect to the feed ethanol concentration and also to the temperature dependence.     

Graft polymerization of acrylic acid onto polyphenylene sulfide nonwoven initiated by low temperature plasma

Graft copolymerization of acrylic acid (AA) onto polyphenylene sulfide (PPS) nonwoven initiated by low temperature plasma was studied. The effects of various conditions on graft reaction and the grafting rate were investigated. SEM images showed that PPS nonwoven was grafted, and the graft copolymerization only occurred on the surface of PPS. It may be due to the chain transference going with the graft copolymerization. It was found that with the increasing of plasma power, treatment time, space between electrodes, monomer concentration, and temperature of graft polymerization, the grafting rate increased at first, went to the top, and then decreased. The PPS nonwoven surface graft reaction could be optimized by the following processing conditions: 120 s of plasma treatment time, 50 W of plasma power, 1.5 cm of space between electrodes, 30% (w/w) of monomer concentration, and 50°C of temperature of graft polymerization. Measurement of XPS showed that the peak of C1s of graft polyacrylic acid was existed, and the peak area increased with the increase of the grafting rate. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5884–5889, 2006     

Plasma-induced hydrogel grafting of vinyl monomers on polypropylene

Polypropylene (PP) film was plasma-treated using a 13.56 MHz direct plasma with argon, nitrogen, and oxygen as the plasma-forming gases. The three gases induced very different changes on the PP film surface, which were studied using contact angle measurements. Because of its degrading and oxidative effect, oxygen plasma pretreatment was not used for the homogeneous grafting of acrylic acid and acrylamide. Nitrogen plasma treatment did not lead to the formation of stable peroxides on the film surface and did not undergo grafting reactions. This may be due to the types of radicals and functional groups created on the surface during the plasma treatment. Finally, argon plasma pretreatment was found to be the most effective for the grafting of vinyl monomers. The amount of grafted poly(acrylic acid) was shown to be proportional to the concentration of peroxides created by argon plasma treatment.     

从生物量生产丙烯酸的研究和开发进展

1 INTRODUCTION Energy resources are divided into two categories: renewable and non-renewable. The fossil energy re- sources, such as petroleum, coal, natural gas and nu- clear energy, are non-renewable, whereas solar energy, hydraulic energy, wind power as well as biomass, etc., are renewable. Nowadays, worldwide efforts to reduce atmospheric CO2 emissions and to overcome the shortage and sharp price rise of fossil energy resources, especially petroleum, simultaneously trigger research on…     

功能性丙烯酸锌树脂的防污性能研究

通过海上挂板实验,对引入具有杀菌作用有机酸和辣素单体的功能性丙烯酸锌树脂的防污效果进行了测试;对比了由2种不同丙烯酸锌树脂制得的防污涂料与国外防污涂料的防污效果。结果表明,功能性丙烯酸锌树脂及由它制成的防污涂料均具有良好的防污性能。     

Improving the dyeability of synthetic fabrics with basic dyes using in situ plasma polymerisation of acrylic acid

The in situ polymerisation of acrylic acid using low temperature plasma treatment was carried out on polyester, polyamide and polypropylene fabrics with the aim of improving their dyeability with basic dyes. The overall colour strength obtained was significantly increased as a result of this treatment. However, while the wash fastness was acceptable on polyamide, it was unsatisfactory on polyester and polypropylene fabrics, probably due to lack of penetration of these fibres by the acrylic acid monomer. Scanning electron microscopy and Fourier transform infrared spectroscopy confirmed that grafting of polyacrylic acid had taken place only on the surface of the polyester and polypropylene fibres, but in the case of polyamide the interior of the fibre was also modified.     

二元共聚高吸醇性树脂的合成及性能研究

将水溶性单体甲基丙烯酸二甲氨基乙酯（ＤＭ）盐酸盐及丙烯酸（ＡＡ），用低温等离子体引发其水溶液共聚合，制得了吸甲醇率高达１４０倍的高吸醇性树脂。对影响吸醇性能的多种因素进行了研究，得出实验条件下的最佳合成条件为：后聚合时间为２２ｈ，放电时间为３０ｓ，放电功率为１５０Ｗ，单体质量分数为４０％，丙烯酸中和度为２１．６％，单体配比（ｍ（ＤＭ）：ｍ（ＡＡ））为４：１。另外，本树脂具有较快的吸醇速度，其值小于     

丙烯酸装置急冷塔顶含酸废水回收利用

深入研究丙烯酸装置工艺流程后,通过工艺管线改造,将原作为废水进行焚烧处理的含丙烯酸和醋酸的急冷塔顶D140凝液,改用为配制阻聚剂的溶剂。有效降低了丙烯酸废水处理量,节约了配制阻聚剂所需除盐水,回收了凝液中的丙烯酸和醋酸,为企业增加了经济效益。     

丙烯海松酸的合成研究

通过松香与丙烯酸的Diels-Alder加成反应制备了丙烯海松酸,考察了原料摩尔比对反应的影响。实验结果表明,随着丙烯酸用量的增加,产物的酸值和软化点逐步升高至不变;紫外光谱研究发现,随着丙烯酸用量的增长,枞酸型树脂酸相对含量下降,而海松酸型树脂酸的含量未见显著变化;气相色谱-质谱联用分析显示,在松香树脂酸与丙烯酸的加成反应中,树脂酸中的海松酸、异海松酸、脱氢枞酸等不参与反应,而长叶松酸、枞酸和新枞酸异构化为左旋海松酸,与丙烯酸发生加成反应;即使丙烯酸过量,长叶松酸和枞酸转化率最高也只可以达到91%和86%;研究还发现,加成产物丙烯海松酸有二种构造异构体,分别占丙烯海松酸量的20%和80%。     

质子酸催化丙烯酸水合制备3-羟基丙酸

以质子酸为催化剂．研究了质子酸类型对丙烯酸水合的影响及最佳工艺条件。结果表明．反应的收率只与H^＋浓度有关,与酸的种类无关。以磷酸为催化剂,最佳的丙烯酸水合条件为：V（丙烯酸）：V（水）=1：5．pH值0．6、反应温度120℃、反应时间3h,在此条件下,丙烯酸的转化率为78．81％,3-羟基丙酸的选择性为92．38％。