Thermostable epoxies

Amino-terminated oligomers are used for hardening cyclocarbonate-terminated oligomers [29-31], Today, for thermostable epoxy compositions, aryl amines are used, which are toxic and require curing temperatures of more than 80°C. For thermostable epoxy and cyclocarbonate compositions, combinations of these oligomers are used with silicones [29],... 

The physico-mechanical, thermal, and adhesion properties of the synthesized polyfunctional PSs are dependent on the nature of functional groups in the aromatic ring. In this case, the following are properties of the chlorohydrin and epoxy groups highest elasticity, resistance to strike, and adhesion properties with carboxyl and olefinics. Furthermore, the—CO—CH=CH-—COOH group was provided new properties such as the photosensitive capability. Functionalized PSs obtained are characterized by their high thermostability, adhesion, and photosensitivity. 

Monooxygenase Assays. Incubation media contained the following (final concentrations) 0.05M phosphate buffer, pH 7.A, glucose-6-phosphate (G-6-P, 2.3 mM), G-6-P dehydrogenase (3 units), NADP (0.23 mM), and KC1 (2.8 mM), and various tissue preparations. Substrates were added in small volumes (25 yl or less) of MeOH. Samples (1.1 ml) were shaken in a thermostated (usually at 22°C) water bath and reactions terminated by enzyme denaturation. Specific analytical procedures for aldrin epoxi-dation (13), 1 CH30-p-nitroanisole 0-demethylation (1A), and 3H-benzo(a)pyrene oxidation (15) have been described. 

Crosslinking has no specific direct effect on thermal degradation crosslinks can be either weak points (e.g., tertiary carbons in polyester or anhydride-cured epoxies) or thermostable structural units (e.g., trisubstituted aromatic rings in phenolics, certain epoxies, or certain thermostable polymers). Indirect effects can be observed essentially above Tg crosslinking reduces free volume and thus decreases 02 diffusivity. It also prevents melting, which can be favorable in burning contexts. 

Chemical resistance and thermostability of nano-heterogenic coatings with fluorine surface active additives (FSAA) are approximately 5%-10% higher than for unmodified ones. At the same time, addition of about 3 mass% of metal oxides in epoxy-rubber nanostructured compositions significantly decreases their permeability and increases their chemical resistance in water and water solutions of acids, salts, and alkalis (Figure 6.3) [8],... 

Although the data concerning these polymers are quite limited, both TCBP euid TCBS (as well as some of their appropriate derivatives) have been incorporated into thermoplastic and thermoset resin systems including polycarbonates (9,10,11), polysulfones (12), thermostable (aromatic) polyesters (13), alk polyesters ( ), unsaturated polyesters Tl5,16) and epoxy resins (16). 

High temperature polymers may be defined as those macromolecules which retain useful physical properties for periods >10,000 hours at 450 F or for >1,000 hours at 500-550 F. Stated alternately, these polymers perform satisfactorily at temperatures above the limits of epoxies or phenolics liqtllcit in the designation "high temperature" or "thermostable" polymer are two basic criteria ... 

G. Das and N. Karak, Thermostable and flame retardant Mesua ferrea L. seed oil based non-halogenated epoxy resin/clay nanocomposites . Prog Org Coat, 2010,69,495-503. 

Epoxy-modified Mesua ferrea L. seed oil-based polyurethane/clay nanocomposites at different loadings (1-5 wt%) have been studied as biocompatible biomaterials. The partially exfoliated nanocomposites were prepared by an ex situ solution technique under high mechanical shearing and adequate ultrasonication at room temperature. The nanocomposites exhibited enhanced mechanical properties such as tensile strength (twofold) and scratch hardness (five-fold), thermostability (to about 40°C), and an increase in the rate of biodegradation between five- and ten-fold. All the nanocomposites showed RBC haemolysis inhibition observed by anti-hemolytic assay carried out on the sterilised films. 

Bisphenol-A-based epoxy with a poly(amido amine) hardener system cured Mesuaferrea L. seed oil-based hyperbranched polyurethane (HBPU)/ clay nanocomposites obtained by an ex situ solution technique, was also reported. The partially exfoliated nanocomposites showed a two-fold improvement in adhesive strength and scratch hardness, 10 MPa increments in tensile strength and thermostability at 112°C with little effect on impact resistance, bending and elongation at break compared to a pristine epoxy-modified HBPU system. However, similar epoxy-cured Mesua ferrea L. seed oil-based HBPU/clay nanocomposites exhibited a two-fold increase in tensile strength, a 6°C increase in melting point and thermostability at 111°C after nanocomposite formation using an in situ technique. An excellent shape recovery of about 96-99% was observed for the nanocomposites. The above observations confirm that the performance characteristics of nanocomposites are influenced by their preparation technique. 

This epoxidised oil/nanoclay mixture is used as an efficient reactive diluent in commercial bisphenol-A-based diglycedyl ether epoxy, enhancing performance characteristics such as cure rate, tensile strength, impact and scratch resistance, thermostability and chemical resistance. ... 

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