Epoxy aromatic amine-cured

This paper will deal mainly with this type of polymers, focussing on the glassy state of epoxy-aromatic amine-cured polymers. However, many aspects of network glasses cannot be understood without considering the chemistry of their formation, degree of crosslinking, and behaviour in the rubbery state, which will be briefly referred to. 

Polystyrene insulation on magnet wire 0.29 Encapsulated with B-staged aromatic amine cured aliphatic amine cured bisphenol A-epichlorohydrin epoxide (epoxy transfer moulded). Impregnate. 

The complex sorption behavior of the water in amine-epoxy thermosets is discussed and related to depression of the mechanical properties. The hypothesized sorption modes and the corresponding mechanisms of plasticization are discussed on the basis of experimental vapor and liquid sorption tests, differential scanning calorimetry (DSC), thermomechanical analysis (TMA) and dynamic mechanical analysis. In particular, two different types of epoxy materials have been chosen low-performance systems of diglycidyl ether of bisphenol-A (DGEBA) cured with linear amines, and high-performance formulations based on aromatic amine-cured tetraglycidyldiamino diphenylmethane (TGDDM) which are commonly used as matrices for carbon fiber composites. 

Temperature-resistant two-part, elevated-temperature curing epoxy adhesives can be formulated with aromatic amines, such as metaphenylenediamine (MPDA), methylene dianiline (MDA), or a eutectic blend of the two. These adhesives will provide relatively high temperature strength, but they are generally brittle. When mixed with epoxy resin at concentrations of about 15 pph for MPDA and 26 pph for MDA, they provide complete cure in about 30 min at 175°C. The aromatic amines also provide a working life of several hours at room temperature. Starting formulations for aromatic amine cured epoxy adhesives are shown in Table 12.4. 

In conclusion to the short analysis on curing chemistry of epoxy-aromatic amine networks (for more detailed analysis see papers of K. Dusek and B. Rozenberg in this volume), one can say that the chemical structure of the polymers under consideration is mainly determined by the curing reaction in Eq. (I). Equation II becomes important only for polymers with an excess of epoxy groups at T 150 °C. This rather simple situation makes the analyzed polymers very suitable for basic investigations. 

Post-cure thermal treatment of epoxy-aromatic amine polymers stabilizes mechanical properties to a certain extent. However, the embrittlement makes the treatment harmful from the point of view of engineering material properties. 

The most common cure conditions for the networks under consideration are Tcure < T and Tcure = const. Under these conditions, the most important feature of the thermosetting process is the vitrification of the reacting mixture which practically quenches chemical crosslinking (see Sect. 2) and changes the physical and mechanical properties of the reacting mixture. In this section, we shall mainly consider the properties of epoxy-aromatic amine glasses prepared at Tcure = 40-110 °C. 

SOLVENT RESISTANCE OF AROMATIC AMINE-CURED HYDANTOIN EPOXY RESIN... 

TtMiOK i [Uniroyal] Aromatic amine curing agent, fixtifier fix epoxy resins fix molded mechanical goods. 

One possible adhesive formulation contains 20 pbw (parts by weight) of epoxy resin, 70 pbw of filler, and 10 pbw of a reactive diluent and an aromatic amine curing agent such as diamino diphenylsulfone (DADS) whose amine-equivalent weight is 62. If the resin is Epon 825 or DER 332, having an epoxy equivalent of 174, the modified EEW will be ... 

Because of the excellent cooperation of a major oil company, buried oil field flow lines in Crane County, Texas are the most thoroughly documented application of fiberglass pipe. In 1961 and 1962 oil field flow lines in this major production area were installed using unlined aromatic amine cured epoxy, filament wound pipe. At that time, this type of pipe was a relatively new product, which had a good short term record as an economical solution to corrosion problems in oil field applications. Prior to the development of epoxy fiberglass pipe, cement lined steel with cathodic protection was the standard piping system for this type of oil field service. 

Two lines, installed in 1962, were selected by the owner and the pipe manufacturer as a site for obtaining much needed data which could be used to determine the long term corrosion resistance of unlined aromatic amine cured epoxy fiberglass pipe in typical oil field flow line service. It was agreed that sections of pipe would be removed at regular intervals and tested so that the physical properties could be compared with the original properties of the pipe. This section documents the results of the 25 year history of these pipelines. 

IR spectroscopy was used to follow the ageing processes of two types of epoxy resins. Resin samples were exposed to ionising radiation and the effects at the molecular level were determined. Aromatic amine cured resins were oidy slightly affected by the radiation, but those cured by alkyl diamines were more sensitive and thus absorbed more water molecules (41). 

Staychip 3100/ Cookson High-Tg, aromatic-amine cured epoxy (sihca filled) <1 Ceramic, laminates Dispense, capillary underfill FUp-chip in package or flip-chip on board... 

Toughening oftetrafiinctional epoxies has proven especially difflcult. However, by use of specially formulated polysulfones and polyetherimide thermoplastics, toughening and improvement in hot/wet properties have been achieved for two tetrafunctional epoxies cured with an aromatic amine curing agent. 

Fig. 3.1. Effect of water on the fracture energies of bonded joints, as a function of time, (a) Aromatic amine cured epoxy, b) Aliphatic amine cured epoxy, (c) Epoxy polysulphide.

Adhesive A = aromatic amine-cured epoxy Adhesive B = aliphatic amine-cured expoxy... 

Combined tertiary/secondary amine curatives, prepared from ter-tiary/primary diamines and epoxy resins, have been used as accelerators for primary aromatic amine cures of DGEBA-type epoxy resins. For example, diethylaminopropylamine/DGEBA resin adducts have been used in m-phenylenediamine-cured epoxy resin systems to provide relatively low temperature cures (50-160°C). The cured resin systems have good toughness and heat distortion temperatures near 130°C. 

Table 18.4 Comparative Chemical and Thermal Resistance of Bisphenol A, Aromatic Amine-Cured vs. Bisphenol F (Epoxy Novolac)...

Dyakonov T, Chen Y, Holland K, Drbohlav J, Burns D, Velde D V, Seib L, Solosky E J, Kuhn J, Mann P J and Stevenson W T K (1996), Thermal analysis of some aromatic amine cured model epoxy resin systems - I Materials synthesis and characterization, cure and post-cure , Polym Degrad Stab, 53, 217-242. doi 10.1016/0141-3910(96)00085-7. 

Polyhalogenated aromatic amine curing agents for epoxy resins that impart flame retardance [151],... 

Kim and Robertson [203] studied the toughening of an aromatic amine-cured diglycidyl ether of bisphenol A epoxy with particles of crystalline polymers. The crystalline polymers chosen were polyfbutylene terephthalate) (PBT), nylon-6, and polyCvinylidene fluoride) (PVDF). Each of these was found to be capable of un-... 

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