Heat-resistant Resin Research Articles

Soluble and fusible polyamides and polyimides containing pyrazoline moieties and their crosslinking to heat-resistant resins

3-(4-Aminophenyl)-5-(3-aminophenyl)-2-pyrazoline as well as the 1-acetyl- or 1-benzoyl-substituted derivatives of this compound were synthesized and used for preparing a new series of polyamides and polyimides. Characterization of polymers was accomplished by inherent viscosity, 1H-NMR, 13C-NMR, x-ray, DTA, TMA, TGA, and isothermal gravimetric analysis. The properties of polymers were correlated with their chemical structures. They were amorphous or microcrystalline and soluble in polar aprotic solvents, CCl3COOH, and m-cresol. The polyamides showed an excellent solubility being soluble even in o-dichlorobenzene, 1,2-dichloroethane, and chloroform. The polymers displayed Tg at 127–163°C and softening at 150–195°C. The polyamide bearing unsubstituted pyrazoline moieties was remarkably more hydrophilic than those containing 1-acetyl- or 1-benzoyl-substituted pyrazoline segments. Upon curing, crosslinked polymers were obtained and their thermal stability was evaluated. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1353–1361, 1997

A novel type of low dielectric and heat-resistant resin for printed wiring boards

We developed a novel type of low dielectric and heat-resistant resin. The resin was synthesized from dehydrating reaction between fused aromatics and 1,4-benzenedimethanol, therefore, it was called advanced polyCOndensed fused PolyNuclear Aromatic Resin (advanced COPNA-Resin). The advanced COPNA-Resin exhibited characteristic properties for an electrical insulator: e.g., high Tg (250/spl deg/C), low dielectric constant (3.1 for 1 MHz), and low water absorption (0.37 wt.%). We studied fabrication and properties of prepregs, double-sided copper-clad laminates, printed wiring boards with copper-plated through-holes using advanced COPNA-Resin as an insulating material. Prepregs were fabricated by the dipping process of E-glass or T-glass fiber woven fabrics into the resin solution. Copper-clad laminates were obtained by hot-press fabrication of advanced COPNA-Resin prepregs. The laminates reinforced by E-glass fiber woven fabric exhibited characteristic properties for multilaying printed wiring boards. Tg was 255/spl deg/C. The dielectric constant was 4.2. Advanced COPNA-Resin laminates exhibited higher Tg and lower dielectric constant than polyimide laminates known as heat-resistant and low dielectric materials. The linear thermal expansion coefficient of advanced COPNA-Resin laminates for xy-axis was 4-5 ppm, and that for z-axis was 29 ppm. Advanced COPNA-Resin printed wiring board exhibited outstanding reliability of electrical connection of copper-plated through-holes in comparison with the epoxy or the polyimide system. From those analysis for Tg, dielectric constant, linear thermal expansion coefficients, and through-hole reliability, the advanced COPNA-Resin was regarded as novel type of advanced material for high-density interconnects such as fine-pitch surface mount and multichip modules.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Dynamic mechanical properties of multi-functional epoxy resin filled with aramid short fibers

Three heat resistant multi-functional epoxy resin were filled with Aramid (Technora®) short fibers (AFP) by 2.4 wt% using four kinds of hardeners. AFPs observed by SEM on the fracture surface were dispersed randomly. Dynamic mechanical properties and flexural strength of those composites were measured. Although the glass transition temperatures Tg of the multi-functional epoxy resin matrix varied when combined with different hardeners, they were all high (over 200° C) and the highest temperature reached 260° C. The storage modulus E' of the material increased when AFP was added and remained at over 2 GPa even at 150° C. The value of E' in the glassy region was higher than the estimated value by the rule of mixtures which shows that the effect of AFP filling was remarkable. The relative modulus at Tg and the ratio of the peak height of tan δ implied that the affinity of epoxy resin with AFPs was large. The flexural strength of the matrix (epoxy resin) for less tough materials was larger than that for tough...

Heat-resistant resins derived from cyano-substituted Diels-Alder polymers

Two structurally different monomers bearing furan terminal groups and cyano pendant groups were synthesized and polymerized with 4,4′-bismaleimidediphenylmethane (BMDM) through a Diels-Alder type reaction. In addition, furfurylamine reacted with half molar amount of terephthaloyl dichloride in the presence of triethylamine and the product obtained reacted with BMDM to yield a reference polymer. The starting materials as well as their intermediate compounds were characterized by FT-i.r., 1H-NMR spectroscopy and elemental analyses. The curing behaviour of monomers was investigated by DTA. It was shown that the Diels-Alder reaction between the maleimide and furan segments occurred at considerably lower temperature than that required for crosslinking of BMDM itself. Crosslinked resins were obtained upon curing the Diels-Alder polymers through their pendant cyano groups. They displayed higher thermal stability than that of reference polymer.

Processable heat-resistant resins based on novel monomers containing o-phenylene rings: 2. Ordered benzoxazole- and benzthiazole-imide copolymers

Highly processable heat-resistant resins containing o-phenylene rings have been prepared with high molecular weight from the reaction of simple aromatic dianhydrides with aromatic diamines containing preformed bisbenzoheterocyclic groups connected by an o-phenylene ring. Thus, 2,2′- o-phenylene-bis(5-aminobenzoxazole) was polycondensed with 3,3′4,4′-benzophenone dianhydride to yield a polyamic acid precursor, which was converted to an ordered benzoxazole-imide copolymer via cyclodehydration. Polymers can be prepared from diamines that are structural isomers, e.g. the amino groups can be in the 6-position instead of the 5-position. Additionally, polymers have been prepared from diamines, e.g. 2,2′- o-bis(6-aminobenzothiazole), having structurally similar heterocyclic units such as benzothiazole in place of benzoxazole rings. The preparation of the dinitro precursors to the bisbenzoheterocyclic diamines and their reduction is described along with nuclear magnetic resonance data. Polymers were characterized by differential scanning calorimetry, thermogravimetric analysis and inherent viscosity measurements of the polyamic acid precursors.

Synthesis, characterization, and curing of unsaturated polyamides derived from 2,6‐di(4‐carboxystyryl)pyridine and 2,6‐bis(4‐carboxybenzylidene) cyclohexanone

AbstractTwo new series of heat‐curable polyamides were prepared utilizing the unsaturated dicarboxylic acids 2,6‐di(4‐carboxystyryl)pyridine (DCSP) and 2,6‐bis(4‐carboxybenzylidene)cyclohexanone (BCBC) as starting materials. They were prepared from the condensation of 4‐carboxybenzaldehyde with a half molar amount of 2,6‐dimethylpyridine or cyclohexanone, respectively. The dicarboxylic acids reacted with various aromatic diamines, utilizing triphenyl phosphite and pyridine as condensing agents, to yield polyamides. In addition, two model diamides were prepared by condensing the dicarboxylic acids with aniline. Characterization of starting materials, polyamides, and model compounds was accomplished by IR and 1H–NMR spectroscopy. The curing behavior of polyamides was investigated by DTA. Upon heat‐curing, the unsaturated polyamides were crosslinked through their olefinic bonds to afford insoluble, heat‐resistant resins. The thermal stability of the resins was evaluated by TGA and isothermal gravimetric analysis (IGA). The cured resins were stable up to 310–322°C in N2 or air and afforded anaerobic char yield of 57–69% at 800°C.

Heat‐resistant adhesive resins derived from bismaleimides and bisnadimides containing amide linkages

AbstractA novel class of bismaleimides and bisnadimides containing amide linkages in their backbones were synthesized and characterized. The synthesis of these polymer precursors was carried out by reacting a diamine containing amide linkages with maleic/nadic anhydride. They were alternatively prepared by reacting the monomaleamic/monoadiamic acid of an aromatic diamine (1 mol) with terephthaloyl chloride (0.5 mol) and subsequent cyclodehydration. The latter new preparation method circumvented the hydrogeneration necessary in the first method of synthesis. The monomers were characterized by infrared (IR) and proton nuclear magnetic resonance (1H‐NMR) spectroscopy. Differential thermal analysis (DTA) of monomers showed that bisnadimide and bismethylnadimide were polymerized at lower temperatures than the corresponding bismaleimide. Thermogravimetric analysis (TGA) in nitrogen and air atmosphere revealed that all polymers were stable up to 321–363°C. Their char yield at 800°C under anaerobic conditions was 49–67%.

複合材料母材としての耐熱性ポリイミド樹脂

複合材料母材としての耐熱性ポリイミド樹脂

Corrosion is lost profit

Corrosion is lost profit. A statement constantly made and always relevant. To the layman the food industry presents the most innocent and trouble free of all major industries, regrettably this is not the case. Corrosion is as serious and costly as in the chemical industry attack on steel and concrete are commonplace and many solutions have been tried. One approach which has been found to give excellent cost effective results is the lining of steel and concrete with resin based materials. Development over many years has produced an extensive range of filled and reinforced corrosion and heat resistant resin materials which can be applied to give protection to steel and concrete substrates.

Pressure Balanced Type Membrane Covered Polarographic Oxygen Detectors for Use in High Temperature-High Pressure Water, (I)

A pressure balanced type membrane covered polarographic oxygen detector was developed to determine directly oxygen concentrations in high temperature, high pressure water without cooling and pressure reducing procedures. The detector is characterized by the following features: 1. The detector body and the membrane for oxygen penetration are made of heat resistant resin.2. The whole detector body is contained in a pressure chamber where interior and exterior pressures of the detector are balanced.3. Thermal expansion of the electrolyte is absorbed by deformation of a diaphragm attached to the detector bottom.4. The effect of dissolved Ag+ on the signal current is eliminated by applying a guard electrode. As a result of performance tests at elevated temperature, it was demonstrated that a linear relationship between oxygen concentration and signal current was obtained up to 285°C, which was stabilized by the guard electrode. The minimum 02 concentration detectable was 0.03 ppm (9.4×10−7 mol/kg).

Pressure balanced type membrane covered polarographic oxygen detectors for use in high temperature-high pressure water, (I) Application of guard electrode to improve detector performance at temperatures above 200.DEG.C.

A pressure balanced type membrane covered polarographic oxygen detector was developed to determine directly oxygen concentrations in high temperature, high pressure water without cooling and pressure reducing procedures. The detector is characterized by the following features: 1. The detector body and the membrane for oxygen penetration are made of heat resistant resin.2. The whole detector body is contained in a pressure chamber where interior and exterior pressures of the detector are balanced.3. Thermal expansion of the electrolyte is absorbed by deformation of a diaphragm attached to the detector bottom.4. The effect of dissolved Ag+ on the signal current is eliminated by applying a guard electrode. As a result of performance tests at elevated temperature, it was demonstrated that a linear relationship between oxygen concentration and signal current was obtained up to 285°C, which was stabilized by the guard electrode. The minimum 02 concentration detectable was 0.03 ppm (9.4×10−7 mol/kg).

Heat-resistant resins obtained by polycondensation of aromatic aldehydes with methylpyridines

Polycondensation of terephthalic aldehyde with 2,4 — or 2,6-dimethyl -, or 2,4,6 — trimethylpyridine leads to a new kind of heat-resistant resin with aromatic-heterocyclic structure. These resins are mixtures of thermosetting oligomers. A few components have been identified after separation by size-exclusion chromatography. Although infrared spectroscopy sheds some light on certain aspects of their heat-curing mechanism, this has not yet been fully elucidated. Derivatives of trimethylpyridine (symmetrical collidine) appear to be particularly interesting in view of their possible use with reinforcing fibre materials for prepreg fabrication. These derivatives lead to composite materials whose high mechanical properties remain unaffected for several thousand hours at 250°C and a few hours at 350°C. These products are being developed on an industrial scale under the name of PSP resins.

Pressure balanced type membrane covered polarographic oxygen detector for use in high temperature-high pressure water.

A pressure balanced type membrane covered polarographic oxygen detector was developed to determine directly oxygen concentrations in high temperature, high pressure water without cooling and pressure reducing procedures. The detector is characterized by the following features: 1. The detector body and the membrane for oxygen penetration are made of heat resistant resin. 2. The whole detector body is contained in a pressure chamber where interior and exterior pressures of the detector are balanced. 3. Thermal expansion of the electrolyte is absorbed by deformation of a diaphragm attached to the detector bottom. 4. The effect of dissolved Ag+ on the signal current is eliminated by applying a guard electrode. As a result of performance tests at elevated temperature, it was demonstrated that a linear relationship between oxygen concentration and signal current was obtained up to 285°C, which was stabilized by the guard electrode. The minimum 02 concentration detectable was 0.03 ppm (9.4×10−7 mol/kg).

Megabit bubble memory process using a new type resin and TaMo alloy-Au conductor

A newly developed heat resistant resin, ladder type organosiloxane polymer, is applied to 8 μm period 1 megabit bubble memory devices. Propagation bias margin and reliability are discussed, comparing with the conventional SiO lift-off planar process. TaMo alloy-Au system is also introduced for the conductor. Interdiffusion, electromigration, and corrosion resistance of Au and refractory metals are studied.

耐熱性樹脂による繊維強化プラスチック

耐熱性樹脂による繊維強化プラスチック

Thermal barriers for rocket motors

AbstractThe very high temperatures associated with rocket motors have necessitated the development of new materials and techniques for thermally insulating various rocket components. Refractory fibres, in combination with heat resistant resins, have proven to be most promising. Composite materials such as metal‐ceramic combinations have also been used to meet the needs of special applications. Techniques developed at the Canadian Armament Research and Development Establishment for using these new materials in a 17‐inch diameter solid propellant rocket motor are described in detail.

Hazards to health. Epoxy resins.

DURING the past decade hard, tough, heat-resistant resins of the epoxy or epoxide type have been used with increasing frequency in surface coatings (for cans, tanks and washing machines), adhesives, plastic capsules for electronic components, castings and structural laminates. The basic resins are viscous, sticky materials that may be cured or hardened by the addition of various polymerizing agents known as hardeners, catalysts, accelerators or curing or crosslinking agents. Before solidification the resin-catalyst mixture may be brushed or sprayed on surfaces or cast in molds. It may be successively alternated with sheets of fiber glass in strong, durable laminates, which . . .