Role of unsaturated groups in glow discharge polymerization

The role of unsaturated groups of the starting compounds in glow discharge polymerization was investigated by elemental analysis, infrared spectroscopy, and ESCA. Tetramethylsilane (TMS), trimethylvinylsilane (TMVS), and ethyltrimethylsilane (ETMS) were used as starting materials. Glow discharge conditions (W/FM value meaning the rf power input per mass of the monomers) as well as a degree of the unsaturation of the starting materials had strong influences upon the polymer deposition rate and the elemental composition of the formed polymers. The C_1s and the Si_2p spectra showed that the chemical composition of these polymers was distinguished by either presence or absence of the unsaturated groups in the starting compounds rather than kind of the unsaturated groups. The polymer formation, when the monomers containing double and triple bonds were served, is proceeded not only through these unsaturated bonds but also through the cleavage between Si and C atoms.     

Surface properties of polymers prepared from trimethylsilyldimethylamine and hexamethyldisilazane by glow discharge polymerization

Polymers prepared from the monomers trimethylsilyldimethylamine and hexamethyldisilazane by glow discharge polymerization were analysed by elemental analysis and infrared spectroscopy, and some surface properties were investigated. Although the polymers formed from both monomers have similar chemical structures involving CH₂, CH, Si---CH₃, Si---CH₂---CH---₂---Si, Si---O---Si, and Si---O---C groups, there is a significant difference in nitrogen residues. The nitrogen residues in polymers formed from trimethylsilyldimethylamine exist mainly as amide groups, and the residues in the polymers from hexamethyldisilazane exist as disilazanyl groups. This difference is evident in the surface energy, especially in the polar contribution. The relative ratio of polar and to dispersive contributions to the surface energy is higher for the polymers from hexamethyldisilazane (0.6) than for those from trimethylsilyldimethylamine (0.3). Adhesion between these plasma films and polymer substrates subjected to modification was also examined.     

Preparation of siloxane-like films by glow discharge polymerization

Glow discharge polymerizations of tetramethoxysilane (TMOS), tetramethylsilane/oxygen mixture (½ molar ratio) (TMS/O₂), hexamethyldisiloxane (HMDSO), and tetramethyldisiloxane (TMDSO) were carried out for the preparation of thin, polymeric films with siloxane structures. The chemical composition of the formed polymers was examined by elemental analysis, infrared spectroscopy, and electron spectroscopy for chemical analysis (ESCA) in connection with polymerization conditions, especially, a level of the radiofrequency (rf) input power per mass of the monomers (W/FM value). The polymers prepared from HMDSO at fairly low W/FM values resembled in chemical composition the conventionally polymerized polydimethylsiloxane. The surface properties of the formed polymers also were evaluated by the measurement of surface energy.     

Poly(alkenylsilane sulfone)s as positive electron beam resists for two-layer systems

Alternating copolymers of sulfur dioxide and vinyltrimethylsilane (VTMS) and terpolymers with allyltrimethylsilane (ATMS) and 1-butene have been synthesized by low-temperature, free radical-initiated polymerization. The co-polymers with VTMS were soluble but hydrolytically unstable. Whereas the copolymer from ATMS was insoluble, terpolymers containing less than 75 mol-percent ATMS (relative to butene) were soluble in a variety of organic solvents. Moreover, they were stable against hydrolysis and had good film forming properties. Their electron beam sensitivity was 1.5 °C/cm² at 20 keV. and their contrast was ～2. The terpolymers have been used as a top imaging layer in a two-layer resist system to transfer half-micron features into a 1.2μm-thick Novolac planarizing layer by oxygen reactive ion etching (O₂, RIE).     

Electropolymerization and electrochemical properties of (N-hydroxyalkyl)pyrrole/pyrrole copolymers

In this study, the N-hydroxyalkyl derivatives of pyrrole (Py), N-(2-hydroxyethyl)pyrrole (HE) and N-(3-hydroxypropyl)pyrrole (HP), were synthesized. The corresponding homopolymers, PHE and PHP, together with the copolymers of Py/HE and those of Py/HP were prepared by galvanostatic polymerization. These monomers and polymers were characterized by FTIR spectroscopy, elemental analysis, SEM and electrochemical techniques. The result of potential-time profiles showed that a higher potential was required for HE and HP than Py for the polymerization. This was ascribed to the steric hindrance of high concentration of the N-hydroxyalkyl groups. However, a similar potential was observed for the copolymerization of Py/HE and Py/HP systems as that of Py due to the reduction of the steric effect by lower content of the substituent. The SEM micrographs showed a rougher morphology for the films synthesized from the solutions with higher Py/derivatives ratio. The cyclic voltammograms indicated that all the copolymers were larger, while the homopolymers had smaller anodic/cathodic currents and specific charges than PPy. This implied that the existence of the proper amount of the N-hydroxyalkyl pendant groups enhanced the ionic mobility of the pyrrole polymers. The results of charge/discharge measurements showed that the copolymer PYHP82 has the highest discharge capacity among the pyrrole polymers prepared.     

High voltage electrical discharge reactions of fats and related compounds

Studies are reported on the modification of fats and related compounds by electrical discharge reactions. Several types of fatty compounds were subjected to silent electrical discharge of the ozonizer type of 15,000 volts AC and analyzed by gas-liquid and thin-layer chromatography, infrared spectral and elemental analyses. Evidence was obtained for a free radical reaction in accordance with the general theory of discharge reactions. The major products of the reaction were polymers of varying degrees of complexity. Shortchain hydrocarbons were also detected. Hydrogenations via the formation of hydrogen radicals was demonstrated; branching via long-chain radical interreactions was also indicated. The incorporation of nitrogen and oxygen into polymeric products was demonstrated when the reaction was carried out in the presence of these gases. Reaction mechanisms are proposed to explain the products formed under various conditions.     

1,3-双(3-羟丙基)-1,1,3,3-四甲基二硅氧烷(BHTS)的合成及表征

采用三甲基硅氧烷及六甲基二硅氮烷与丙烯醇反应制得烯丙氧基三甲基硅烷(ATMS),对比二种方法得知用六甲基二硅氮烷制备时操作更加方便,产率可达到100%;再从ATMS出发,经硅氢加成,醇解生成1,3-双(3-羟丙基)-1,1,3,3-四甲基二硅氧烷(BHTS),反应简单,安全,产率为90%。通过红外和核磁对各段产物进行表征,基本符合设想。     

Glow discharge polymerization of trimethylvinylsilane and tetramethylsilane

Glow discharge polymerizations of trimethylvinylsilane (TMVS) and tetramethylsilane (TMS) were compared. Vinyl groups in TMVS slightly contribute the polymer-formation process only when glow discharge polymerization was performed at the W/FM parameter less than 500 MJ/kg. Elemental compositions of the polymers prepared from TMVS, which are rich in carbon content, shows strong dependence on operational conditions, the W/FM parameter; but the polymers from TMVS consist of the almost same chemical structures as those from TMS. Slight differences between the starting materials in chemical structure does not reflect on bulk properties of the formed polymers but on surface properties such as surface energy and adhesion.     

Ultra-Thin Polymer Layer Deposition by Aerosol–Dielectric Barrier Discharge (DBD) and Electrospray Ionization (ESI) at Atmospheric Pressure

Polyolefins are chemically inert and do not adhere well to metals, polymers or inorganics. To overcome this problem, polyolefin surfaces were modified thermally, plasmachemically, or by flame treatment with different oxygen-containing groups, however, unfortunately, such treatments were accompanied by undesired, adhesion lowering polymer degradation. To solve this dilemma, solutions of synthetic polymers and copolymers were prepared, sprayed into the barrier discharge or electrosprayed without discharge and deposited as thin adhesion-promoting layers. The deposited polymer layers from poly(vinylamine), poly(ethylene glycol)–poly(vinyl alcohol) copolymers and poly(acrylic acid) were endowed with monotype functional groups. Using the aerosol — dielectric barrier discharge only a fraction of functional groups survived the deposition process in contrast to the electrospray in which all functional groups were retained.     

Synthesis and studies of blue light emitting polymers containing triphenylamine‐substituted fluorene and diphenylanthracene moiety

Photoluminescent (PL) polymers containing triphenylamine‐substituted fluorene and diphenylanthracene (DPA) units were synthesized by aromatic nucleophilic substitution reaction. The light emitting polymers (LEPs) contains hole‐transporting triphenylamine (TPA) groups at the C‐9 position of fluorene and DPA‐emitting segments in the main chain. The obtained polymers were soluble in various organic solvents and thermally stable. The synthesized polymers were successfully characterized by elemental analyses, FTIR and, ¹H NMR spectroscopy. The electrochemical measurements and optical properties of the polymers were also studied. The obtained polymers showed significant blue emission. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and characterization of new aliphatic polyesters containing methanodinaphtho[1,3]dioxocin part

A novel dinaphthodioxocin‐containing diol monomer, 8,16‐methano‐16H‐dinaphtho[2,1‐d:1′,2′‐g][1,3] dioxocin‐2,14‐diol (MDDD) was synthesized in high yield and purity through the condensation of 2,7‐dihydroxynaphthalene with malonaldehydetetramethyl acetal at room temperature. It is used as a new monomer for the synthesis of a series of novel dinaphthodioxocin‐containing aliphatic polyesters by interfacial polycondensation method. The new diol monomer was fully characterized by IR, NMR, mass spectroscopies, and elemental analysis. Optimal conditions for polyesterification were obtained via study of the model compounds. Polyesters derived from MDDD and four aliphatic diacid chlorides had inherent viscosities ranging from 0.26 to 0.38 dL/g. The chemical structure of the polymers was fully characterized by IR, NMR spectroscopies, and elemental analysis. The physical properties of the polymers were studied. All the new polymers show good thermal stability and very good solubility in most organic solvents. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Preceramic organoboron–silicon polymers

Several boron-containing organosilicon polymers were synthesized from a sodium-coupling reaction of silicon and boron halides with and without alkyl halide in hydrocarbon solvents. The B–Si preceramic polymers were characterized using techniques such as IR, UV, and NMR spectrometry, gel permeation chromatography, elemental analysis, molecular weight measurement, and thermal analyses (TGA, DSC, DTA, and TMA). The chemical structures of the preceramic polymers were postulated based on the analytical results. Black ceramic materials were obtained from the precursor polymers upon thermal degradation at temperatures above 1000°C in an inert atmosphere. The precursor polymers had a ceramic yield of up to 70%. Thermogravimetric analysis of the ceramic material in air at a flow rate of 100 mL/min showed it was stable up to 1000°C with little weight gain or loss. Several methods were used to characterize the ceramic materials: XRD, solid NMR, high-temperature DTA, elemental analysis, and acid digestion. The analyses indicated that the ceramic materials comprised a mixture of silicon carbide (SiC), silicon borides (SiB₄, SiB₆), and amorphous Si–B–C ceramics, with small amounts of silica and free silicon.     

Synthesis,characterization and antimicrobial properties of new poly(ether-ketone)s and copoly(ether-ketone)s containing diarylidenecycloalkanone moieties in the main chain

A new category of linear poly(ether-ketone)s IV_a–d and copoly(ether-ketone)s V_a–f containing diarylidenecycloalkanone moieties in the main chain has been synthesized by solution polycondensation of 4,4′-bis (chloroacetyl)diphenylether I , with different phenoxides of diarylidenecycloalkanones II_a–d . The model compound III was synthesized from the monomer I with sodium phenoxide in DMF and K₂CO₃, and its structure was confirmed by elemental and spectral analyses. The resulting polyketones and copolyketones were characterized by elemental and spectral analyses, beside solubility and viscometry measurements. The thermal properties of those polymers were evaluated by TGA and DTA measurements and correlated to their structural units. X-ray analysis showed that polymers having some degree of crystallinity in the region 2θ = 5–60°. In addition, the biological screening and morphological properties of selected examples of the polymers were tested. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Arylidene polymers

Summary A new class of polyconjugated polymers namely poly(2,5-arylidenecyclopentanone) and poly(2,6-arylidenecyclohexanone) has been obtained by condensation of cyclopentanone or cyclohexanone with terephthaldehyde. Copolymerization of the corresponding monomers were also carried out. The model compounds were prepared from cyclopentanone or cyclohexanone with benzaldehyde and their structures were elucidated by IR, NMR, and elemental analyses. The polymers were charactrized by elemental analysis, IR, UV, viscometry, DSC measurements, thermogravimetric and X-ray analyses. Electrical conductivities in the insulating range 10^-10–10^-12 (ohm cm)^-1 were observed for the polymers 1,2, while the copolymers 3 gave 10^-9 (ohm cm)^-1.Doping with iodine increases the semiconducting values of the polymers 10^-7–10^-8 (ohm cm)^-1, whereas the increase in case of copolymer was more distinct 10^-6 (ohm cm)^-1.Presented in the 3rd International Conference Speciality Polymers 88, 13–15 Sept, Quen College Cambridge University, UK (1988)     

Adhesion of glow discharge polymers to metals and polymers

Adhesion of glow discharge polymers to metals and polymers in an adhesive joint was measured by lap-shear test and immersion in hot water of 70°C °C for an extended time. A glow discharge polymer was deposited onto polymers [polyethylene and poly(tetrafluoroethylene)] and metals (aluminum and stainless steel) prior to when the polymer and metal were joined. It is found that the lap-shear strength is enhanced by coating the surfaces of these substrates with plasma film produced from methane, ethylene, and acetylene, and that deterioration of the adhesive bonding part, when immersed in hot water of 70°C, is strongly dependent on the gas used as well as operational conditions where a polymer film is formed. The adhesion of a polymer produced from methane on the polymer and metal is strong enough to apply for durable, adhesive joints.     

Synthesis and characterization of some new thermally stable polyimides and copolyimides bearing bipyridine side-chain groups

A new series of polyimides and copolyimides were synthesized via reaction of new bipyridine containing diamine, 4, 6-bis(4-aminophenyl)-2, 2′-bipyridine, with commercial dianhydrides. 4, 6-bis(4-aminophenyl)-2, 2′-bipyridine was synthesized starting from condensation reactions of 4-nitro acetophenone, 4-nitrobenzadehyde and pyridacyl pyridinium iodide (Krönke salt) and reduction of the desired dinitro compound. The synthesized monomer and polymers were characterized by FT-IR, NMR and CHN elemental analysis. The physical properties of the polymers, including solubility and viscosity were studied, and the results showed acceptable solubility and good chain growth for polymers. Thermal stability of these polymers was also studied by Thermo Gravimetric Analysis (TGA). The polymers start to lose weight because of thermal degradation at about 300 °C. From Differential Scanning Calorimetry (DSC), the polymers were showed T_g between 190 and 230 °C. The morphology of these polymers was also investigated by X-ray Diffraction (XRD), and the results showed only broad reflections originated from their low crystallinities.     

Synthesis and characterization of polyazomethine conducting polymers and oligomers

Conjugated polyazomethine polymers were prepared from the polycondensation of terephthalaldehyde with 4,4′-thiodianiline, and 4,4-thiodibenzaldehyde with 4,4′-thiodianiline, 4,4′-phenylenediamine and benzidine. The polymers showed good stability in air and were soluble in many organic solvents. The electrical conductivities of the undoped and doped (H₂SO₄ and I₂) polymers were studied. Doping the polymers markedly increased their conductivities from 10^?8 ? 10^?11 S cm^?1 (dielectric region) to 10^?3 ? 10^?5 S cm^?1 (semiconducting region). The polymers were characterized by IR spectroscopy, elemental analyses, viscosity measurements and X-ray diffraction. Furthermore, polyazomethine oligomers were prepared and a comparative study of the physical properties of the oligomers and their corresponding polymers was performed. The electrical behavior of the oligomers was studied. It was found that oligomers with a minimum of eight aromatic (Ar) rings gave almost the same electrical conductivities as long-chain polymers.     

Reduction of dissolved oxygen in boiler water using new redox polymers

New polymers were used as catalysts for the removal of dissolved oxygen in boiler water. These polymers, based upon hydroquinone‐quinone redox system, were prepared by polymerization of methyl 4‐(2,5‐dimethoxybenzyl)cinnamate and copolymerization of this monomer with 4‐(4′‐vinylphenethyl)‐1,10‐phenanthroline. The resulting product was used to synthesize polymers containing transition metal ions. Nuclear magnetic resonance, infrared spectroscopy, and elemental analysis were achieved to characterize monomers and/or electron‐transfer polymers. These polymers were used for the removal of oxygen from water. It was shown that the oxygen content was reduced to less than 0.1 mg L^?1 in ～ 70 s. Based on the obtained results, the redox capacity of two polymers were determined. It was established that the poly‐4‐(2,5‐dihydroxybenzyl)cinnamic acid reached a redox capacity of 69.7 mg of O₂ per gram of polymer. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Processable heat-resistant polymers: 14. Polyamides and polyamideimides containing azo linkages

Diamines containing azo groups were synthesized by reacting sulphanilamide or p,p′-di(aminophenyl) sulphone with aniline. These diamines were used for the synthesis of polyamides and polyamideimides by interfacial and solution polycondensation techniques. The polymers were characterized by elemental (N and S) analyses and by i.r. and u.v. spectroscopy. The physical, chemical, thermal and electrical properties of the polymers were studied. The polymers were found to be soluble in highly polar solvents. The thermal stability of polyamideimides is superior to that of polyamides. X-ray diffraction and electrical behaviour of the polymers were also reported.     

Effect of electrodeless glow discharge on polymers

The effects of gas plasma generated by electrodeless (inductive coupling) glow discharge on polymers were investigated as functions of gas pressure, discharge power, exposure time, and type of plasma gas. A remarkable similarity between the plasma susceptibilities of low molecular weight organic compounds and polymers was observed; i.e., polymers which have ether, carbonyl, ester, or carboxylic acid attached to a nonaromatic structure are very susceptible to plasma. The weight loss was proportional to the exposure time and exposed area. The discharge power and type of gas were found to have a great influence on both the rate of weight loss and the morphology of the exposed surface. The predominant effect of plasma on polymers was found to be degradation (manifested by weight loss). The crosslinking effect was found to be marginal with many polymers; however, significant crosslinking was observed with double bond-containing polymers. The crosslinking was examined by swelling the treated films. With copolymers of styrene–butadiene, 4-vinylpyridine–butadiene, methacrylic acid-butadiene, and acrylic acid–butadiene, the crosslinking was greatly dependent on the discharge power, the butadiene content of the copolymers, and the exposure time. Both degradation and crosslinking by gas plasma were generally limited to the exposed surface; however, the propagation of crosslinking in the direction of thickness was observed with copolymers of styrene–butadiene. The plasma of organic vapor also cause degradation of plasma-susceptible polymers, particularly at high wattage, although the deposition of polymer occurs simultaneously.