Crosslinked methacrylate copolymer

Polymerization of styrene or methyl methacrylate by macroazoinimers having two vinyl groups (MIM-2v) resulted in crosslinked block copolymers, while macroazoinimers with one vinyl end (MIM-1 v) group to polymerize vinyl monomers yielded branched block copolymers. 

Figure 3. Time dependence of the fraction R of unreacted aminostyrene residues during acetylation by 0.14 M acetic anhydride at 30°C. Methyl methacrylate copolymer in acetonitrile solution (0) linear poly-(methyl methacrylate-co-butyl methacrylate) swollen with acetonitrile Cd) methyl methacrylate copolymer crosslinked with 1 mole% ( ) and with 15 mole% ( ) ethylene dimethacrylate poly(methacrylate crosslinked with 3 mole% ethylene dimethacrylate containing entrapped poly(methyl acrylate-co-aminostyrene) ( ).

Murray et al. (2) prepared permeable membranes for selectively removing phosphate, nitrate, and ferric cations by polymerizing and crosslinking with the modified matrix monomer, (bis-acrylamindo-phenanthroline)dinitrate, (IV), to produce an ion permeability substrate. Kulkami et al. (3) selectively removed cobalt cations from solution using 2-hydroxy ethyl methacrylate copolymers,... 

F14. —, and S. Loshaek Cross-linked polymers. I. Factors influencing the efficiency of crosslinking in copolymers of methyl methacrylate and glycol dimethacrylates. J. Am. Chem. Soc. 75, 3544 (1953). 

The preparation of cellulose copolymers with vinyl monomers, which have functional groups that are hydrophilic in nature, has given textile products with improved soil release properties. For example, as shown in Figure 5, crosslinked cellulose-poly (methacrylic acid) copolymer fabrics exhibited both increased oily and aqueous soil release during washing compared with the crosslinked control fabrics. However, for oily soil, when softeners were added to the wash water, this improvement in soil release decreased. Crosslinked cellulose-poly (hydroxyethyl methacrylate) copolymer fabrics exhibited no improvement in oily soil release and only slight improvement in aqueous soil release compared... 

The internal cross-linking of styrene copolymers is dealt with in the chapter of R. N. Haward, B. M. Parker and E. F. T. White, who prepared a copolymer of styrene and hydroxyethyl methacrylate and crosslinked the copolymer with hexamethylene diisocyanate. 

Figure 2. Reproducibility of the viscosity change for replicate crosslinking runs. Styrene-hydroxyethyl methacrylate copolymer (2.2 mole % HEM A) concentration in toluene 0.09% (gram/dl.) [NCO- 0 [OH- 0 = l...

Table I. Light Scattering for Styrene—Hydroxyethyl Methacrylate Copolymer (3.8 mole % HEM A) before and after Crosslinking with Hexamethylene Diisocyanate...

To study the internal crosslinking of styrene-hydroxy ethyl methacrylate copolymers, it was necessary to prepare a range of well characterized materials containing only low concentrations of hydroxyethyl methacrylate. To ensure that the copolymers were of uniform composition, only low monomer conversions were used so that the composition of the monomer mixtures did not change appreciably during the reaction. Low polymerization temperatures were used to obtain high molecular weight copolymers. 

In a related patent (46) Amagi et al. synthesized a triple latex IPN. In brief, polymer 1 was a crosslinked SBR, polymer 2 was a crosslinked styrene-methyl methacrylate copolymer, and polymer 3 was a crosslinked poly (methyl methacrylate). All three were sequentially synthesized on the same latex particle. The latex material was then mechanically blended with linear poly (vinyl chloride). Also, Torvik (47) blended together four polymers that had different glass transition temperatures. 

Of the reported materials, the only commercially available resists are one of the MMA-MAA/MMA-MACl compositions and a t-butyl methacrylate copolymer material (13). In this work, we have chosen to examine the copolymer mixture, which crosslinks at a temperature of 160°C compared to 250 C for the single copolymer. We have carried out experiments to optimize its use for direct write electron beam lithography. 

Copolymer with styrene and 1,4-divinylbenzene, 10% alkaloid incorporation, 20% crosslinking. d Copolymer with hydroxyethyl methacrylate and ethylene glycol dimcthacrylate, 10% alkaloid incorporation, 20% crosslinking. 

Smets reviewed the topic of photoinitiated cationic polymerisation at the Kyoto meeting and described some novel interesting work from his own laboratory. Diazonl-um salts were used to photoinitiate the polymerisation of N-vinylcarbazole or to crosslink linear copolymers of methyl methacrylate and glycidyl methacrylate through the epoxy groups of the second comonomer. 

Fig. 17. Dependence of rates of crosslinking and scission on the composition of methyl methacrylate copolymers irradiated in the form of films and A chain scission, crosslinking [reproduced from Ref. 89].

Kiura, M. Atarashi, J.I. Ichimura, K. Ito, H. Ohtani, H. Tsuge, S. Tacticity of methacrylic copolymers and their crosslinked polymers studied hy pyrolysis-gas chromatography. J. Appl. Polym. Sci. 2000, 78, 2140-2144. 

Latex with hydroxyl functionalised cores of a methyl methacrylate/butyl acrylate/2-hydroxyethyl methacrylate copolymer, and carboxyl functionalised shells of a methyl methacrylate/butyl acrylate/methacrylic acid copolymer was prepared by free radical polymerisation. The latex was crosslinked using a cycloaliphatic diepoxide added by three alternative modes with the monomers during synthesis dissolved in the solvent and added after latex preparation and emulsified separately, then added. The latex film properties, including viscoelasticity, hardness, tensile properties, and water adsorption were evaluated as functions of crosslinker addition mode. Latex morphology was studied by transmission electron and atomic force microscopy. Optimum results were achieved by introducing half the epoxide by two-step emulsion polymerisation, the balance being added to the latex either in solution or as an emulsion. 8 refs. 

Details are given of the synthesis of a crosslinked isopropylacrylamide-butyl methacrylate copolymer which has thermo-sensitive swelling behaviour. The copolymer was studied for applications as a thermal on-off switch for a pulsatile drug release system. 2 refs. 

In general, swelling in water increases with increased content of 2-HPMA in the copolymer. Exceptions are the copolymers of HPMA (0.668)-EA (0.332) and HPMA (0.632) -BA (0.368). This was confirmed by repeated experiments. The reason for this strange behaviour is unknown. Compared toacrylate copolymers, swelling of methacrylate copolymer in water is significantly high, for crosslinked as well as for uncrosslinked copolymers. 

Consistent with our prediction, the dienyl methacrylate copolymers crosslinked rapidly on exposure to air-Jto form coatings with excellent appearance and durability. The 2,5-cyclohexadienylmethyl methacrylate copolymer with butyl and methyl methacrylate is an interesting exception. The only reaction of the cyclohexadiene groups which we could see was their oxidative conversion to benzene rings. 

Fig. 7.17. Crosslinking on baking methyl methacrylate copolymer resist (see...

If crosslinking or copolymer precipitation occurs, bulk polymerization may be difficult to handle. A suspension process may then be the only feasible way in which the copolymerization can be carried out [4]. Suspension processes also provide a means of investigating copolymerization kinetics at high conversion. The monomer sequence in styrene-methyl methacrylate copolymers at high conversion have been found to differ from those observed at low conversion [77]. 

PEX crosslinked polyethylene SMMA styrene methyl methacrylate copolymer... 

Ethylene-Glycidyl methacrylate copolymer (E-GMA) Epoxide 3-8% GMA Moderate high reactivity with carboxyl group of PA Lg, hardness limit achievable toughness Crosslinking tendency... 

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