Urethane acrylic monomer

Figure 3.84. Voxel obtained by irradiation of a mixed urethane acrylate oligomer and a urethane acrylate monomer in the presence of a mixture of benzoyl cyclohexanol and morpholino phenyl amino ketones at 780 nm using a 150-fs pulsed Ti sapphire mode-locked laser operating at 76 MHz, where light was focused by a 1.4 numerical aperture objective lens (a) scanning electronic microscopic images of the voxel and (b) longitudinal and lateral voxel size as function of the exposure time. (From Ref. [580] with permission of the American Institute of Physics.)...

Analysis of fluorescence of urethane acrylic monomer copolymerized with trans-4-(2-methacryloyloxyethylcarbamoyloxymethyl)stilbene (SUM) was performed (Figure 3.19) [73]. 

Liquid organic rubbers with reactive functionality can be prepared by several methods. End-functional oligomers are preferred. Chains attached to the network at only one end do not contribute as much strength to the network as those attached at both ends [34], Urethane chemistry is a handy route to such molecules. A hydroxy-terminated oligomer (commonly a polyester or a polyether) can be reacted with excess diisocyanate, and then with a hydroxy methacrylate to form a reactive toughener [35]. The methacrylate ends undergo copolymerization with the rest of the acrylic monomers. The resulting adhesive is especially effective on poIy(vinyl chloride) shown in Scheme 2. 

There are two approaches to forming urethane-acrylic hybrids. First, an acrylate terminated urethane oligomer can be used [147]. Alternatively, polyisocyanate and benzoyl peroxide can be combined in one side of the adhesive, and methacrylate monomers and urethane curatives (especially polyols) in the other [148]. 

Urethane acrylates Urethane acrylates are formed by the reaction of isocyanates with hydroxy-functional acrylate monomers. After UV cure, they produce tough, flexible materials, which exhibit a good abrasion resistance. 

Structural adhesives are formulated from epoxy resins, phenolic resins, acrylic monomers and resins, high temperature-resistant resins (e.g., polyimidcs), and urethanes. Structural adhesive resins arc often modified by elastomers. 

Figure 11.3. By choosing a suitable monomer, the degree of branching, and molecular weight of the polyester, one can customize the properties of the resulted polyester acrylate oligomers, such as flexibility (Tg), viscosity, functionality, reactivity, and other end properties of the final coatings. The performance properties of polyester acrylates lie between those of epoxy acrylates and urethane acrylates (Table 11.2).

Chem. Descrip. Aliphatic urethane diacrylate oligomer with acrylate monomer (30%) diluent... 

Uses Urethane-acrylic, solv. resist, aid, abrasion resist, aid in coatings, screen inks, overprint varnishes, wood coatings, plastic film, laminating adhesives, floor tile, and metal coating finishes Features Resilient, nonyel. supplied as base resin or as resin/monomer blends which offer resilience, water-wh. clarity, and exc. heat and light stability to UV/EB-cured prods. 

Chem. Descrip. Aliphatic urethane diactylate/monomer blend Uses Urethane-acrylic in plastic and wood coatings Features Dilution of urethane oligomer with Photomer 4061 (TPGDA) to facilitate easier handling and applic. tough and abrasion resist. Properties High m.w. 

Chem. Descrip. Waterborne aliphatic polyurethane polymer Uses Urethane, film-former for automotive vinyl coatings Features U V-curable no free acrylate monomer forms a hard, high gloss, chem. resist, film when dried and UV cured Properties Translucent dens. 8.80 Ib/gal vise. 150 cps pH 7.8 tens. str. 5300 psi elong. 140% (break) hardness (Sward) 44 VOC 266 g/l 35% solids 9.19% NMP Sancure 853 [Noveon]... 

Chem. Descrip. Etherified acrylated melamine/formaldehyde resin (62-68%) in tripropylene glycol diacrylate Uses Crosslinking agent in radiation-cure applies, such as polyester and epoxy acrylates, unsat. polyesters, aliphatic and aromatic urethane acrylates, and most acrylate monomer diluents imparts hardness and gloss, stain and chem. resist, to coatings, paper coatings Features Cured by free radical polymerization initiated by U V or thermal processing... 

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