Über CH‐aktive polymerisationsinitiatoren. XIII. Mitt. Polymerisationen und polymerisationsinitiatoren

Abstract

ZUSAMMENFASSUNG:Verbindungen der allgemeinen Formel A-CH(R)-B, wobei A und B elektronenanziehende Gruppen, R ein Wasserstoffatom oder eine Alkylgruppe darstellen, wirken bei der Polymerisation von Monomeren (Methacrylsiuremethylester, Acrylnitril, Styrol, Vinylacetat u. a.) in Gegenwart von Cu++, C1-und Luftsauerstoff oder Peroxyden als Initiatoren. Die =CHR-Gruppe kann auch Glied eines carbo-oder heterocyclischen Ringes sein, z.B. in cyclischen P-Oxocarbonsaureestern, p-Oxolactonen, P-Diketonen, Pyrazolonen oder Barbitursiuren. Die Polymerisationsauslosung wird auf eine Autoxydation der aktiven CH-Gruppe zum Hydroperoxyd zuruckgefuhrt, das die Polymerisation auslost. SUMMARY:Compounds with the general formula A-CH(R)-B (A and B mean electron attracting

Multi-purpose Bonding Performance of Newly Synthesized Phosphonic Acid Monomers

“…This ternary initiator system markedly reduced the adverse effects on both polymerization and adhesion 23) , without undesirable salt formation 16,23) between the [-P(C=O)(OH)2] moiety and amines, and hence increased the cohesive force of adhesive resin between the adherends 15) . Much attention has been paid to the use of barbituric acid derivatives for dental resins, derived from their C-H active and amine-free polymerization initiating ability, since a study by Bredereck et al 25) . However, little attention has been paid to evaluate the effect of 5-monosubstituted barbituric acid (5-MSBA) in combination with an aromatic sulfinate amides (ASA) and t-BPMA on adhesion 23) .…”

“…To date, details of the polymerization initiation mechanism of these ternary initiator systems are still unknown. Nonetheless, the initiating behavior of 5-MSBA could be triggered by autooxidation of C-H at the 5-position of barbituric ring in the presence of a base 23,25) . Thus, the barbituric acid derivatives that can exhibit polymerization initiating function are restricted by the C-H active 5-MSBA 25) , such as CEBA 23) and BPBA 23) .…”

“…Nonetheless, the initiating behavior of 5-MSBA could be triggered by autooxidation of C-H at the 5-position of barbituric ring in the presence of a base 23,25) . Thus, the barbituric acid derivatives that can exhibit polymerization initiating function are restricted by the C-H active 5-MSBA 25) , such as CEBA 23) and BPBA 23) . As for sulfinate amide, i.e., p-TSMo 23) , it could be synthesized by the reaction between an amide compound and an aromatic sufinate chloride, which could be prepared from an aromatic sulfinate sodium salt such as p-TSNa.…”

“…As for CEBA (white needle crystals, mp 115-117.5 ), it was synthesized according to a method previously reported 23,25) . As for t-BPMA, it was purchased from Nihon Oil and Fat Co. Ltd. (Tokyo, Japan) and used without further purification.…”

Compact polymeric 3D prints of high stability

“…To guarantee that this process starts exactly when the ink hits the powder, a two-component initiator system was used, comprising barbituric acid that was premixed with the powder and copper(II) ions dissolved in the ink. [16][17][18] (iii) It is particularly important that the ink distributes controllably within the powder bed. The entire height of a print layer must be filled with the ink, so that the resulting monomer-polymer mixtures of successive print layers interdiffuse and form a stable connection.…”