Adhesion Properties of Films of Polypyromellitimide Modified in a Direct-Current Discharge

Adhesion properties of films of polypyromellitimide modified in a direct-current discharge on the anode are investigated. The peeling strength in when in contact with a series of polymers and with the use of adhesives of different chemical natures is measured using the T-peel test according to ASTM 1876–01. It is shown that the action of a direct current discharge on the films of polypyromellitimide makes it possible to substantially improve the adhesion properties of the polymer to adhesives of different types.     

Polypropylene Films in a Direct-Current Discharge

The effect of dc discharge treatment on polypropylene films—both commercial and stabilizer- and plasticizer-free as prepared under laboratory conditions (with the rac-Et(Ind)₂ZrCl₂–methylaluminoxane catalytic system)—was studied. The discharge treatment was shown to hydrophilize the polypropylene surface in both cases. Negative charged states were detected on the modified surface and their relation to the polypropylene hydrophilization was established. By the thermostimulated relaxation and depolarization techniques, it was shown that the observed charges are induced by injection of plasma electrons into the polymer. It was found that severe changes took place throughout the bulk of the polypropylene film synthesized over the metallocene catalyst, as indicated by enhancement of its crystallinity and a change in the molecular mass distribution.     

Contact Properties of Polytetrafluoroethylene Films Modified in Nonthermal Plasma of Atmospheric-Pressure Argon Glow Discharge

High Energy Chemistry - It has been shown that plasma treatment of the surface of a polytetrafluoroethylene film in nonthermal plasma of atmospheric-pressure glow discharge makes it possible to...     

Charging of Polycarbonate Films in a Direct-Current Discharge

The effect of treatment of Diflon, Makrolon^®, and Lexan^® polycarbonate films in the cathode fall of a dc discharge was studied. Plasma treatment was shown to result in the hydrophilization of the film surface. The dependence of the contact angle on the discharge current and treatment time was examined. It was found that the discharge induced a negative charge on the polycarbonate surface. The surface-charge density was correlated with the contact angle for various treatment conditions. Space charging processes in glow discharge-treated films were investigated using the thermally stimulated relaxation and depolarization techniques. The role of produced charged entities in an increase in the surface energy of modified polycarbonate films was revealed.     

采用XPS与接触角法研究氟聚合物表面结构与性能

本文采用接触角和变角XPS方法对FA共聚物的表面能、 表面微相结构做了进一步的研究.     

Surface Energy and Adhesive Properties of Polyamide 12 Modified by Barrier and Radio-Frequency Discharge Plasma

Summary. The polyamide 12 foil with sufficient surface and adhesive properties to other substrates can be prepared by discharge plasma modification. For improvement of bonding and printing of polymer a surface barrier discharge plasma in N₂ and O₂ as well as a radio-frequency discharge plasma in air has been studied. A significant increase in surface energy of the polymer as well as in strength of adhesive joint to more polar polymer was found. The chemical changes of PA 12 modified by plasma were analyzed using fourier transform infra red – attenuated total reflection (FTIR–ATR) spectroscopy, and X-ray photoelectron spectroscopy (XPS) measurements. The observed changes of surface properties of the polymer due to aging were not important.     

Surface Energy and Adhesive Properties of Polyamide 12 Modified by Barrier and Radio-Frequency Discharge Plasma

The polyamide 12 foil with sufficient surface and adhesive properties to other substrates can be prepared by discharge plasma modification. For improvement of bonding and printing of polymer a surface barrier discharge plasma in N₂ and O₂ as well as a radio-frequency discharge plasma in air has been studied. A significant increase in surface energy of the polymer as well as in strength of adhesive joint to more polar polymer was found. The chemical changes of PA 12 modified by plasma were analyzed using fourier transform infra red – attenuated total reflection (FTIR–ATR) spectroscopy, and X-ray photoelectron spectroscopy (XPS) measurements. The observed changes of surface properties of the polymer due to aging were not important.     

Modification of Polyvinyltrimethylsilane in Direct-Current Discharge

High Energy Chemistry - The modification of polyvinyltrimethylsilane under treatment by direct-current discharge at a reduced pressure has been investigated. Polymer films were placed at the anode...     

有机硅改性丙烯酸环氧单酯光-热混杂固化体系的表面性能

以有机硅改性丙烯酸环氧单酯为树脂配制了一系列紫外光-热混杂固化体系.通过FTIR表征了光-热固化过程双键和环氧特征吸收峰的变化.研究了不同的稀释剂对光固化和光-热混杂固化膜的凝胶率、吸水率、表面水接触角等性能的影响,并用能谱仪(EDS)测试了固化膜表面硅元素的含量.结果表明:光固化膜的凝胶率低于86.5%,而光-热混杂固化膜的凝胶率在97.0%左右.与丙烯酸环氧单酯光-热固化体系相比,有机硅改性丙烯酸环氧单酯光-热固化膜的表面水接触角有显著提高,由62.53°提高到99.27°,EDS测试也表明有机硅有富集于固化膜表面的特性.     

Effect of Glow Discharge Conditions on Structure and Thermal Properties of Polysilazane Thin Films

Polysilazane thin films were prepared by glow discharge polymerization of hexamethylcyclotrisilazane in mixture with various gases: argon, nitrogen, hydrogen and ammonia. The effect of gas type on thermal stability and chemical structure of glow discharge polysilazane was studied. Thermo-gravimetric measurements performed within a temperature range of 20–1000° C, showed that the best thermal stability was exhibited by polysilazane prepared at the presence of ammonia in the reaction mixture. IR analyses data revealed that polymers prepared from mixture with ammonia or hydrogen contained more Si-H groups than those obtained with argon or nitrogen. It proves that in the presence of ammonia or hydrogen, greater monomer fragmentation through Si-C bonds cleavage takes place. More detailed investigations were carried out for polysilazanes prepared in mixture with ammonia. It was found that thermal stability as well as chemical structure of polymer depend strongly on polymerization conditions, i. e., ammonia contents in the reaction mixture, deposition time, discharge current density. Thermal stability of polysilazane improved with the increase in deposition time and current density. Increasing these parameters caused also the Si-NH-Si bonds content in the polymer to grow. The results prove that ammonia is a reactive comonomer and that the polymerization of hexamethylcyclotrisilazane at the presence of this gas may proceed through the formation of Si-NH-Si bonds.     

Polymerization of 3-Methoxythiophene in a Direct-Current Discharge

Thin polymer films were obtained from 3-methoxythiophene at the cathode in a dc discharge. It was found using Fourier transform IR spectroscopy that thiophene rings were the main structural units of the polymer; aliphatic fragments and oxygen-containing groups were also present. The polymer based on 3-methoxythiophene was found to exhibit p-type intrinsic conduction with an activation energy of 0.045 eV. The conductivity of the polymer at 20°C was 10⁻⁸ Ω⁻¹ cm⁻¹, and doping with iodine resulted in a rise in conductivity to 10⁻³ Ω⁻¹ cm⁻¹.__________Translated from Khimiya Vysokikh Energii, Vol. 39, No. 5, 2005, pp. 382–385.Original Russian Text Copyright © 2005 by Drachev, Gil’man, Krasovskii, Costa-Belobrzeckaja.     

Evaluation of the Distribution Depth of Charge Injected by Direct-Current Discharge Plasma into Thin Polyimide and Poly(ethylene terephthalate) Films

The dynamic capacitor method was proposed for determining the distribution depth of negative charge induced in the surface layers of thin polymer films under exposure to a dc discharge as a result of trapping plasma-injected electrons, and equations for calculation were obtained. Charge distribution in thin poly(pyromellitimide) and poly(ethylene terephthalate) films with different thickness (1–6 m) was experimentally studied, and the negative charge due to the injection of electrons from plasma was found penetrate to a depth greater than 0.5 m.     

自组装超薄膜修饰Ta2O5介质膜及其特性研究

采用静电自组装方法在五氧化二钽(Ta2O5)介质氧化膜上制备了聚二烯丙基二甲基氯化铵(PDDA)/聚苯乙烯磺酸钠(PSS)和聚二烯丙基二甲基氯化铵/聚-3,4-乙烯二氧噻吩-聚苯乙烯磺酸钠(PEDOT-PSS)超薄膜.研究了两种自组装超薄膜在Ta2O5介质氧化薄膜上的组装特性.结果表明两种自组装膜能够稳定地组装于Ta2O5介质膜表面,并有效降低薄膜的表面粗糙度.进一步研究了两种自组装超薄膜修饰的Ta2O5电容结构的电性能.结果表明静电自组装膜对Ta2O5介质膜表面进行修饰后,有效地隔离了介质氧化膜中的缺陷,降低了电容的漏电流并提高耐电压能力;研究还发现不同厚度的超薄膜对Ta2O5电容结构的耐压特性有不同程度的影响,较厚的薄膜可以更好地提高电容的耐压能力并降低漏电流,但会增加电容的等效串联电阻(ESR).另外,在相同薄膜层数的情况下,聚合物电解质PEDOT-PSS良好的导电性能降低了复合超薄膜的电阻,使得PDDA/PEDOT-PSS修饰的电容结构ESR值较低.     

聚醚接枝聚硅氧烷共聚物改进环氧树脂表面性能的研究

共混改性;形态;聚醚接枝聚硅氧烷共聚物改进环氧树脂表面性能的研究     

Conducting Polymer Layers Obtained by Direct-Current Discharge Polymerization of 1-Amino-9,10-anthraquinone

The polymerization of 1-amino-9,10-anthraquinone in a direct-current discharge was studied. It was found that polymer films with a conductivity of 10^–5–10^{–4 –1} cm^–1 were formed at the cathode. It was assumed that the semiconductor properties are due to the presence of a conjugated cyclic moiety in the films. The layers deposited at the anode turned out to be typical dielectrics with a conductivity of 10^{–16 –1} cm^–1.     

Structure and Properties of the Surface Layers of Thin Films of Poly(1-trimethylsilylpropyne)

The birefringence of thin films of poly(1-trimethylsilylpropyne) with 55 : 45 ratio of units with transand cisconfigurations of the -C = C- bonds was studied by the method of an oblique polarized beam. The surface birefringence coefficients were determined for films of various thicknesses. A theory of birefringence in the surface layers of polymer films was suggested, based on the assumed exponential decrease in the orientation order parameters of the molecular chain fragments with increasing distance from the film surface.     

含氟丙烯酸酯聚合物乳胶膜表面性质

采用XPS和界面张力仪分别测定了含氟丙烯酸酯聚合物乳胶膜表面的组成及水在其表面的动态接触角, 并用状态逼近方程模型计算了含氟聚合物乳胶膜的表面张力, 考察了温度对乳胶膜润湿性的影响. 结果表明, 含氟聚合物乳胶膜表层较深处的F 1s信号强度比近表面要弱, 乳胶膜表面张力随表面氟原子浓度增加在一定程度上呈现线性下降；含氟侧链(Rf)较长(碳原子数n＞6)的含氟聚合物, 其表面张力随Rf单元含量增加而下降的趋势显著高于Rf较短(n≤6)的含氟聚合物, 而水在含氟聚合物乳胶膜表面上的后退接触角θr随n增大出现急剧上升, n≥10 时, θr值几乎恒定不再随n增大而改变. 此外, 参与共聚的非氟丙烯酸酯酯基碳链较短时, 水在共聚物乳胶膜表面的θr随氟单元含量增加而增加的趋势更显著；温度超过40 ℃后, 水对聚合物乳胶膜的润湿性随温度上升略有改善.     

Surface Properties of Fluorinated Acrylate Polymer Latex Films

The surface chemical compositions of fluorinated latex films and the dynamic contact angles of water were determined using X-ray photoelectron spectroscopy (XPS) and a Kruss interface tension measurement, respectively. The surface tensions of the films were calculated by the equation of state approach using the dynamic contact angles, and the effect of temperature on the wetting behavior of these films was investigated. It was shown that the F 1s signal intensity from the outermost surface of these fluorinated latex films was stronger than that from the interior surface of the film and that the surface tension showed a linear decrease with the increase of density of fluorine atoms on the latex film surface to a certain extent. The surface tension rapidly decreased with the increase of fluorinated lateral chains (Rf) content in the copolymer with longer Rf (carbon atom number n>6). The water receding contact angles (θr) on the latex films sharply decreased with the increase of n value, then leveled off nearly at n=10, and remained almost unchanged when n>10. In addition, θr increased more remarkably with the increase of F content in the poly (protonated acrylate- co-fluorinated acrylate) with short hydrocarbon side chains. The water wetting ability of the fluorinate latex films became slightly better only when temperature was more than 40°C.     

Ferroelectric Properties of Modified Lead Titanate Thin Films Obtained by a Sol-Gel Method

Calcium substituted lead titanate thin films have been prepared by a sol-gel method, deposited by spin-coating, and thermally treated so as to obtain a perovskite structure. Two types of thermal treatments were given, differing in the heating rate, which in conventional treatments was of some 10°C/min, and in rapid treatments >500°C/min. With rapid heating, materials are obtained in which greater polarizations are commuted and bias fields are smaller. This, together with the fact that additional (undesired) phases are not observed by X-ray diffractometry when rapid treatments are used, shows that these are to be preferred over conventional treatments.