Hybrid dual curing

Another development has been the advent of the dual-cure resin cements. These are hybrids of glass polyalkenoate cements and methacrylates that set both by an add-base cementation reaction and by vinyl polymerization (which may be initiated by light-curing). In these materials, the solvent is not water but a mixture of water and hydroxyethylmethacrylate which is capable of taking dimethacrylates and poly(acrylic add)-containing vinyl groups into solution. In the absence of light these materials set slowly and... 

One of the most interesting recent developments has been the advent of the resin glass polyalkenoate cements (Antonucci, McKinney Stansbury, 1988 Mitra, 1989 Wilson, 1989, 1990 Mathis Ferracane, 1989 Minnesota Mining Manufacturing Company, 1989 Albers, 1990). They are dual-cure hybrids that set by a combination of acid-base and polymerization reactions, and there are several types. Polymerization is effected by either chemical or light initiation. 

Another mode of dual curing involves the simultaneous occurrence of free radical and cationic radiation-induced cross-linking polymerization of formulations containing appropriate initiators [20, 23, 28]. This method, which is called hybrid curing, leads to coatings with imique properties. A typical hybrid-cure system contains a diacrylate and a diepoxide, the former polymerizing by a free radical and the latter by a cationic mechanism. Exposure of the system to in-... 

S. Peeters, Overview of Dual-Cure and Hybrid-Cure Systems in Radiation Curing, Chapter 6 in Vol. Ill of [7j. 

Peeters, S., Overview of dual-cure and hybrid cure systems in Radiation Curing in Polymer Science and Technology, Vol. 3. Fouassier, J.P. and Rabek, J.F. (Eds.) (pp. 177-217), Chapman and Hall, Andover, 1993. 

Another hybrid system has been proposed for resist applications the simultaneous chain polymerization of N-methylolacrylamide and the acid-catalyzed crosslinking of the resulting polymer with poly(vinyl alcohol) In dual cure plastisols, finally, a solid thermoplastic resin is dispersed in a multifunctional aciyrlate mixture which contains a thermal and a photoinitiator. These plastisols have been proposed for the encapsulation of integrated circuits... 

Organic-Inorganic Hybrid Materials Obtained by the Dual Cure Process... 

Modem approaches in the field of hybrid materials for advanced applications use dual cure processing which, depending on the nature of components, may be (a) a UV-cure followed by a thermal treatment, or (b) a UV-cure followed by a... 

Multicomponent hybrids containing zirconium propoxide, tetraethoxysilane and dimethyl-diethoxysilane, intended for dental restorative or adhesive materials, were successfully obtained by the dual-cure [272]. Zirconium-containing species proved to be highly effective in catalyzing the epoxy polymerization/crosslinking reactions, as compared to those containing Ti, and enhanced mechanical properties, as well as thermal stability of nanocomposites. 

Perfectly transparent hybrid films were obtained by UV/sol-gel dual cure starting from a fiuorinated hydroxyl acrylate monomer, tripropylene glycol diacrylate (TPGDA) and tetraethoxysilane (TEOS) [276]. The hybrids were characterized by an almost complete double bonds conversion, high hydrophobicity and increased surface hardness, Tg values, and tensile modulus. Increased TEOS amounts entailed extensive interfacial interactions through a chemically formed organic-inorganic interphase. 

Malucelli, G. Hybrid organic/inorganic coatings yhrough dual-cure processes state of the art and perspectives. Coatings 6, 10 (2016). doi 10.3390/coatings6010010... 

Malucelli, G., Priola, A., Sangermano, M., et al. Hybrid nanocomposites containing silica and PEG segments preparation through dual-curing process and characterization. Polymer 46, 2872-2879 (2005)... 

Recently, Endo and coworkers have developed novel sulfonium type initiators that can initiate polymerization either upon irradiation or upon thermal treatment. In addition, these photoinitiators are shown to be functional for both cationic and radical polymerizations. This dual activity is particularly important in hybrid curing systems for coatings and adhesions [28]. Scheme 11.6 contains the general steps for the synthesis of these photoinitiators from sulfides. 

Dual polymer network formed by UV-curing and polyaddition of a hybrid acrylate/isocyanate resin. 

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