Crosslinked acrylate

Covalent crosslinking. Acrylic polymers can be covalently crosslinked through direct reaction between functional monomers in the polymer itself or by the addition of a crosslinking reagent, which typically reacts with the functional groups or polymer backbone in the PSA. In general, acrylic polymers are very... 

Instead of using thermal energy to trigger the hydrogen abstraction mechanism, photo-induced reactions can be also be used to successfully crosslink acrylic PSAs [74-76], In this case, photoactive compounds, such as for example those containing benzophenone, anthraquinone or triazine nuclei are compounded with the polymer or copolymerized as one of the monomers. After drying, the adhesive... 

Earlier, successful attempts at physically crosslinking acrylic PSAs have been disclosed in the work of Husman et al. [98], Mancinelli and colleagues [99,100] and others. Instead of making ABA type structures, these authors studied and developed the use of high macromers in acrylic copolymers. Macromers are... 

The demands on the PSA performance for these types of applications can be very high, especially in the areas of creep, shear resistance and long-term durability. For these reasons, crosslinked acrylics and stabilized block copolymer adhesives have become the main PSA material choices. 

Crosslinked acrylic microgels in aqueous and non-aqueous media were patented as paint constituents in 1979 to improve the orientation of aluminum flake pigments, restrict the flow of the liquid coating on the substrate and restrict sagging [324]. As the patent speaks of emulsions, insolubility of the microgels and particle sizes up to 200 nm, it is questionable whether these polymers consisted of microgels only. 

Fujimura, T., Inoue, M. and Uemura, I. (1990). Durability of wood with acryl-high-polymer II. Dimensional stability with crosslinked acryl polymer in wood. Mokuzai Gakkaishi, 36(10), 851-859. 

Swelling data indicate that crosslink density in the continuous phase of the 70 30 and 60 A0 networks is high. Crosslink densities were estimated from the data in Table III by the method of Hill and Kozlowski ( ). Results were for 80 20, "Vg = 10" moles of elastically effective network chains/cm for 70 30, Vg = 2.5 x lO" chains/cm for 60 AO, Vg = A.3 x 10" chains/cm. These estimates suggest that the crosslink densities are within the range reported for conventional, highly crosslinked acrylic HMMM and polyester HMMM enamels (19,20). 

Superabsorbent Polyelectrolyte based on a Crosslinked Acrylic Acid Copolymer... 

Various crosslinked acrylate resists have been reported in the literature, mainly based on methacrylic acid anhydride (MANH) crosslink units. In the simplest case, the anhydride crosslinks may be formed by baking methacrylic acid (MAA) homopolymer, although this... 

CNC FLEX 492 is a self-crosslinking acrylic emulsion whose air dried films are clear, hard and water resistant. CNC FLEX 492 is of particular interest in textile applications because of the very firm hand it imparts to cellulosic or synthetic fabrics. 

Another interesting procedure for obtaining a two-layer system involves [97] the formation of a base layer of the polymeric photoinitiator, through a spin coated film onto different substrates, followed by their immersion, under UV irradiation, into multifunctional acrylic formulations dissolved in solvents unable to remove the base layer from the substrate. By this method, a top layer of crosslinked acrylic resin is obtained, having strong adhesion to the substrate. The replacement of the polymeric photoinitiator by a low-molecular-weight analogue... 

Particle Shape. The delineation of two families of materials on the basis of particle shape is very clear from the electron microscope evidence. That the families are xx, lx and xl, 11 points directly to the presence or absence of crosslinking in the PBMA as a source of particle shape differentiation. Overall concentration of the PBMA precursors is not a strong factor, since the irregular particles were observed in all three of the xx compositions, but an examination of the effect of crosslinker concentration alone was not carried out. In related work on an epoxy-butyl acrylate system in which component polymerization rates and the simultaneity of the reactions were matched, it was reported (3) that, prior to gelation of the matrix, irregular particles of crosslinked acrylate were formed but spherical particles were found in the absence of crosslinker. Together with the observation of an apparent bimodal size distribution, our results are similar, even though our system and conditions are markedly different from those in the earlier study. 

Examples of synthetic polymers include crosslinked acrylate copolymers (carbomers) [67-69] and modified acrylate derivatives (acrylates/alkyacrylate crosspolymers) [70],... 

Choice of the method of separating such superabsorbents is critical for control of their storage stability. Separation is usually achieved by precipitation with a solvent. For example, it was reported that ethanol was superior in this respect, having the additional benefit of increasing the water absorbance of the precipitate.3013 Ethanol, acetone, and 2-propanol did not perform as well as methanol. It was also reported that the precipitate should be neutralized before precipitation and should be dried under conditions preventing moisture loss.3013 The superabsorbency could be increased by the use of crosslinked acrylic acid for grafting to starch.3014 Random, intermolecular hydrogen-bonds were responsible for this effect. 

Abco Binder. [Alx Industries] Nonyellowing, self-crosslinking acrylic enuilsion pigrttent printing binders for textile printing. 

Burco Acrylic DC L. [Burlington Chem.] Self-crosslinking acrylic emul-si(Mi polymer for textile coating indus-try. 

Macrylk. [Ivax Ind tries] Self-crosslinking acrylate emulsion shrinkage and abrasitm improver. 

Traiispalite SS. [Stanley Plastics Ltd.] High grade crosslinked acrylic material. 

Dura Seal. [SchoUer] Crosslinking acrylic resin emulsions dimension stabilizers, body builders, binders, washable and drycleanable finishes for textiles. 

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