4,4 -diaminodiphenylmethane hardener

Figure 12.5 shows an example of the cured structure of a thermoset resin using two different epoxide monomers with two different amine hardeners. The epoxies are triglycidyl p-aminophenol (TGAP) and tetraglycidyl 4,4-diaminodiphenylmethane (TGDDM), which are tri- and tetra-fiinctional, respectively (n = 3 and n = 4, respectively) and the two hardeners are 4,4-diamino-diphenylsulphone (DDS) and dicyandiamide (DICY). 

Aromatic poly amine hardeners These mostly solid hardeners include metaphenylenediamine, diaminodiphenylmethane, and diaminodiphenyl sulfone. In general, these hardeners provide poorer bond strengths and are more sensitive to temperature cycling than the aliphatic amines. Shrinkage is also high. 

Trimellitic anhydride is used as a raw material for plasticizers, as a component in polyesterimides and as a hardener for epoxy resins. High-temperature resistant and high-strength polyimides are produced by the reaction of trimellitic acid chloride with an aromatic diamine, such as 4,4 -diaminodiphenylmethane (e.g. Torlan, Amoco),... 

A widely studied nanohybrid system is based on epoxy-siUca [148,149], which is generally prepared upon blending the epoxy monomer and siUca nanoparticles, followed by the addition of a hardener to perform the curing reaction (e.g., diaminodiphenylmethane [150], diaminodiphenylsulfone [151], diethylphosphite [150], PA-amine [152, 153], or hexahydro-4-methylphthalic anhydride [154]). The compatibility between the epoxide compounds and the colloidal silica was optimized upon mixing the diglycidylether of bisphenol-A together with colloidal suspensions of silica nanoparticles dispersed in methylisobutylketraie [150]. 

Synonyms Tonox HT 972 MDA DDM 4,4 -diaminodiphenylmethane methylenebis(aniline) 4,4 -methylenebisbenzeneamine diaminodiphenylmethane p,p -diaminodiphenylmethane bis(p-aminophenyl)methane DADPM DAPM dianilinomethane 4,4 -diaminoditan 4-(4-aminobenzyl)aniline Ancamine TL araldite hardener 972 curithane dianilinemethane 4,4 -diphenylmethane-diamine Epicure DDM Epikure DDM Jeffamine AP-20 Sumicure M... 

Aromatic Amines. Because of conjugation, aromatic amines have lower electron density on nitrogen than do the aliphatic and cycloaliphatic amines. Consequently, they are much less reactive toward aromatic epoxies. They have longer pot-lives and usually require elevated temperature cures. Aromatic amines are usually solid at room temperature. These hardeners are routinely melted at elevated temperatures and blended with warmed resins to improve solubility. Eutectic mixtures of meto-phenylenediamine (MPD) and methylenedianiline (MDA or DDM) exhibit a depressed melting point resulting in an aromatic hardener that remains a liquid over a short period of time. MDA or 4,4 -diaminodiphenylmethane (DDM), 4,4 -diaminodiphenyl sulfone (DDS or DADPS), and MPD are the principal commercial aromatic amines. A new aromatic amine, diethyltoluenediamine (DETDA) has gained more significant uses in recent years. 

Fig. 17. TAS-tiansfer of aromatic and cycloaliphatic amines hardened bisphenol A epoxy resins from alkaline fusion. Experimental details see Tables 10 and 12. Reference mixture V5 a) di-phenylmethane, b) diphenylsulfone, c) aniline, d) 4.4 -bisC4-hydroxyphenyl]methane, e) 4.4 -diaminodiphenylmethane, D m-phenylenediamine, g) 4.4 -diaminodiphenylsulfone, h) metlw-lenbisl 2-cyclohexylamine]...

It will react with appropriate hardeners (aromatic amines, aliphatic amines, acid anhydrides) to produce a crosslinked product. Two hardeners of practical importance are triethylenetetramine and 4,4 -diaminodiphenylmethane... 

Hardeners are DAPEE = di(l-aminopropyl-3.ethoxy)ether, TETA = triethylenetetramine, DAB = 1,3-diaminobenzene, DDM = 4,4 -diaminodiphenylmethane, DMP = tris(dimethylaminomethyl)phenol, BF3MEA = borontrifluoride monoethylamine... 

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