Polyurethane acrylated

Whilst the aliphatic nylons are generally classified as being impact resistant, they are affected by stress concentrators like sharp comers which may lead to brittle failures. Incorporation of mbbers which are not soluble in the nylons and hence form dispersions of rubber droplets in the polyamide matrix but which nevertheless can have some interaction between mbber and polyamide can be most effective. Materials described in the literature include the ethylene-propylene rubbers, ionomers (q.v.), polyurethanes, acrylates and methacrylates, ABS polymers and polyamides from dimer acid. 

Table 10.3 Properties of polyurethane/acrylic IPNs compared with blends and homopolymers...

The potential of using extrinsic (fluorescent) probes for monitoring the initial stages of oxidation was explored for the photo-oxidation of a UV-cured aliphatic polyurethane-acrylate-based adhesive [68]. The two probes investigated were p-dimethylamino salicylic acid (p-DASA) and 2, 7 -difluorescein (Oregon Green... 

The conversion versus time profiles were recorded by RTIR spectroscopy for a polyurethane acrylate (PUA) formulation (Actilane 20/HDDA in a 1/1 weight ratio) exposed to UV radiation of various intensities (I0). It can be seen in Figure 3 that, after a short induction period due to the inhibitory effect of the oxygen dissolved in the formulation, the rate of polymerization rises rapidly up to a maximum value,... 

Fig.3 Influence of the light intensity on the photopolymerization of a polyurethane-acrylate (PUA) film. — IR response time...

Fig.4 Variation of the rate of polymerization of a polyurethane-acrylate resin with the exposure time.

Table 1 Influence of the temperature on the photopolymerization of a polyurethane-acrylate resin (Light intensity 11 mW cm 2) ...

Polyurethane-acrylic coatings with interpenetrating polymer networks (IPNs) were synthesized from a two-component polyurethane (PU) and an unsaturated urethane-modified acrylic copolymer. The two-component PU was prepared from hydroxyethylacrylate-butylmethacrylate copolymer with or without reacting with c-caprolactonc and cured with an aliphatic polyisocyanate. The unsaturated acrylic copolymer was made from the same hydroxy-functional acrylic copolymer modified with isocyanatoethyl methacrylate. IPNs were prepared simultaneously from the two-polymer systems at various ratios. The IPNs were characterized by their mechanical properties and glass transition temperatures. 

Figure 3. IR spectra of a polyester-acrylate photoresist exposed for various times to nitrogen-laser pulses in the presence of air. (--- polyurethane-acrylate).

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). 

Kansai Paint Polyurethane Acrylic acid ester Solid Dilute sodium hydroxide... 

Polyurethane-acrylate films cured by an electron beam has been... 

Among the countless number of applications of polymers, the construction industry is one which utilises several polymeric materials. In this book I cover those polymeric materials which are single or bicomponent systems and are cured at ambient temperature either with the aid of curing agents or atmospheric moisture. The various polymers used in manufacturing such products include epoxies, polyurethanes, acrylics, silicones, polysulphides, alkyds and polyesters. As a result of innovation, new technologies exist which utilise more than one polymer in a single product. Such systems are discussed in Chapter 10, on hybrid polymers. 

Polycarbonate Conventional adhesives recommended include epoxies, modified epoxies, polyurethanes, acrylics, RTV silicones, cyanoacrylates, one-part elastomers, some epoxy-polyamides, and hot melts (13). 

UV stabilizer particularly effective in styrenic polymers, PVC, unsaturated polyesters, polyurethanes, acrylic polymers and polycarbonates. 

Since the introduction of the first commercial thermoset, Bakelite, based on phenol formaldehyde condensation, a wide range of thermoset materials have been introduced. These are typically designed for specific properties related to their chemistry and processability. Some commercially important thermosets include phenolics, ureas, melamines, epoxy resins, unsaturated polyesters, silicones, rubbers, polyurethanes, acrylics, cyanates, polyimides, and benzocyclobutenes. ... 

MAJOR POLYMER APPLICATIONS alkyd resin, polyurethane, acrylic... 

MAJOR POLYMER APPLICATIONS alkyd, polyurethane, acrylic, rubber, melamine resins, phenoxy, polyester,... 

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