Polymerisation von n‐substituierten maleimiden in epoxidverbindungen, 1

Abstract

ZUSAMMENFASSUNGN-substituierte Maleimide polymerisieren in Glycidethern rnit einer Reaktion erster Ordnung, ausgelirst durch eine Startreaktion zweiter (pseudo-erster) Ordnung. Die Aktivierungsenergie der Startreaktion liegt rnit fast 70 kJ/mol oberhalb, die der Polymerisation mit 48 kJ/mol weit unterhalb der Werte der rein thermischen Maleimidpolymerisation von etwa 60 kJ/mol. Die Werte werden durch DSC-Untersuchungen von Bismaleimiden in Diepoxiden bestatigt. Die Startreaktion verlluft ab 100 "C mit deutlicher Exothermie unter Epoxidverbrauch, Rotfarbung und Bildung von Radikalen rnit g = 2.0034.Die Polymerisation wird durch SBuren und nicht durch Radikalfanger abgebrochen.Es werden Maleimid-Oligomere rnit P, = 5 -7 erhalten, die glycidether-spezifische Gruppen tragen und katalytisch wirken. Eine anionische Initiierung wird diskutiert. SUMMARY:The polymerization of N-substituted maleimides takes place in epoxy compounds according to a first-order reaction initiated by a starting reaction of second (pseudofirst) order. The activation energy of this starting reaction is nearly 70 kJ/mol and is much more as the value of the pure thermal polymerization of maleimides (60 kJ/mol). However, the value of the polymerization reaction of 48 kJ/mol lies far below the pure thermal polymerization. The results were obtained by dilatometry and DSC measurements. The starting reaction shows above 100 OC exothermic effects, consumption of epoxide, red coloration and formation of radicals of g = 2.0034. The polymerization breaks off by acids but not by radical trapping. The obtained maleimide-oligomers with a degree of polymerization P, = 5 -7 contain specific groups of the origin epoxidecompounds and they show catalytic activity. Anionic initiation is discussed. EinleitungN-substituierte Maleimide zeigen das charakteristische Verhalten von 1 ,Zdisubstituierten Ethylenen' -3. Die beiderseits nachbarstiindigen Carbo-0 1990 Huthig t Wepf Verlag, Basel CCC 0003-3 146/90/$03.00

Synthesis and characterization of a thermosetting resins based on 4-(N-maleimidophenylester) hydroxypropylmethacrylate

“…The values of the activation energy obtained for the first reaction peak of the tested systems were in the 57 to 105 kJ/mol (Kissinger method) range, and were comparable with values presented in the literature [30][31][32][33][34]. The activation energy of the second reaction peak of the tested systems, presents was estimated to have values from 65 to 147 kJ/mol (Kissinger method), which are higher than those obtained for the first reaction peak.…”

“…As a consequence of the MDA presence, the Michael-type reaction appears and a small shoulder to the main exotherm of all systems is observed, with the exception of the MPEHPM sample. The literature data for epoxy/BMI/MDA system shown that the homopolymerization is favoured over Michael-type reaction due to the formation of Zwitterions' adduct between the oxirane ring and BMI double bond, even at temperatures as low as 120°C [29][30][31]. The absence of the signal around 915 cm -1 corresponding to the epoxy ring suggests that at this molar ratio there are no unreacted epoxy groups.…”