Photocurable acrylates

V. B. McKoy and A. Gupta. Photocurable acrylic composition, and UV curing with development of. US Patent 5 141990, assigned to California Institute of Technology (Pasadena, CA), August 25, 1992. 

Tooth >1 month Filling Resin Photocuring acrylic resin... 

Yasmuno H, Yoshinaga T, Nakano T (1981) Photocurable acrylic phoshate esters of epoxidized polybutadiene. US Patent 4250007... 

Acrylic resins - [MAGNESIUMAND MAGNESIUM ALLOYS] (Vol 15) - [COATING PROCESSES - POWDER TECHNOLOGY] (Vol 6) -photocuring [RADIATION CURING] (Vol 20) -plasticization of [PLASTICIZERS] (Vol 19) -thiols m [THIOLS] (Vol 24)... 

Reaction-induced phase separation is certainly also the reason for which an inhomogeneous structure is observed for photocured polyurethane acrylate networks based on polypropylene oxide (Barbeau et al., 1999). TEM analysis demonstrates the presence of inhomogeneities on the length scale of 10-200 nm, mostly constituted by clusters of small hard units (the diacrylated diisocyanate) connected by polyacrylate chains. In addition, a suborganization of the reacted diisocyanate hard segments inside the polyurethane acrylate matrix is revealed by SAXS measurements. Post-reaction increases the crosslink density inside the hard domains. The bimodal shape of the dynamic mechanical relaxation spectra corroborates the presence of a two-phase structure. 

As discussed in Chapter 7, radical polymerization can induce marked inhomogeneities, easily observable by DMTA. For example, in photocured polyurethane-acrylate networks, two a peaks corresponding to distinct phases, separated by about 40-100 K, depending on composition and cure conditions, can be observed in the DMTA dissipation spectrum at 10 Hz (Barbeau et al., 1999). 

Curing by light irradiation can be apphed to a variety of polymers. The acrylic family is a typical example of photosensitive monomers. A well-documented review has recently been dedicated to the curing of composites by ultraviolet radiation [45], Photocuring time is much shorter than for traditional thermal curing (minutes rather than hours), leading to a significant reduction in the cycle time. 

Recent concerns over the residual concentration of free thioxanthone photoinitiators and amine coinitiators in coatings and inks on food packaging have resulted in the evolution of macroinitiators <2002PLM4591, 2003JPH(159)103> or polymeric photoinitiators <1996MI379> wherein the thioxanthone unit and, in some instances, the amine coinitiator are covalently bound to a copolymer which is formulated with the ink or coating and then photocured in the normal way. Several copolymers, for example, 636, based upon the polymerization of acrylate esters derived from 4-hydroxythioxanthones with either acrylamide or 2-acryloxyethyltrimethylammonium iodide co-monomer have been explored as water-soluble photoinitiators <2005JPH(169)95>. 

Title Multifunctional (Meth)Acrylate Compound, Photocurable Resin Composition and Article... 

Trifunctional (meth)acrylate fluorine-containing cyclic and acyclic silane compounds have been prepared that form photocurable resin compositions. Coatings from these resins are anti-fouling and resist organic stains from oil mist and fingerprints without detracting from surface mar resistance. 

The reaction of glycidyl acrylate with a-(2-carboxyethyl)benzoin methyl ether has allowed one to obtain [101] the corresponding acrylic monomer which, upon copolymerization with different amounts of MMA, butyl methacrylate and 2-(V, V-dimethylamino)ethyl methacrylate, gives rise to polymeric photoinitiators, containing side-chain benzoin methylether moieties, for photocurable coatings ... 

The polymer-bound photoinitiators have been used to prepare photocurable formulations with epoxyacrylates, urethaneacrylates, trimethylolpropane triacrylate (TMPTA) and HDDA [108]. The above formulations have been UV irradiated on film matrix and the extent of photocuring evaluated in terms of degree of residual acrylic unsaturation at a fixed reaction time. As reported in Table 20, the polymer-bound BAE systems display an appreciably higher photoinitiation activity as compared with that of the low-molecular-weight analogue benzoin isobutyl ether (BIBE) ... 

Several studies have concentrated on the photocrosslinking of epoxy-based resins. Using differential scanning calorimetry the photocuring of epoxy and acrylic prepolymers has been disturbed by the... 

---