Toluene hydroxyethyl methacrylate

ABA type poly(hydroxyethyl methacrylate) (HEMA) and PDMS copolymers were synthesized by the coupling reactions of preformed a,co-isocyanate terminated PDMS oligomers and amine-terminated HEMA macromonomers312). Polymerization reactions were conducted in DMF solution at 0 °C. Products were purified by precipitation in diethyl ether to remove unreacted PDMS oligomers. After dissolving in DMF/toluene mixture, copolymers were reprecipitated in methanol/water mixture to remove unreacted HEMA oligomers. Microphase separated structures were observed under transmission electron microscope, using osmium tetroxide stained thin copolymer films. 

Figure 1. Variation in specific viscosity of a toluene solution of a styrene-hydroxyethyl methacrylate copolymer (2.2 mole % HEM A) on reaction with hexamethylene diisocyanate at 80°C. Polymer concentration 0.047%, (gram/dl.) [NCO] 0 [OH] 0 = 9.5...

Figure 4. Comparison of viscosity changes on reaction between styrene-hydroxyethyl methacrylate copolymer (2.2 mole % HEMA) and butyl isocyanate ( ) and hexamethylene diisocyanate (O) in toluene at 80°C.

Figure 7. Viscosity changes and polymer concentration for the reaction between hexamethylene diisocyanate and sty-rene-hydroxyethyl methacrylate copolymers in toluene at...

Figure 10. Change in viscosity over long times during reaction between styrene-hydroxyethyl methacrylate copolymer and hexamethylene diisocyanate in toluene at 80° C. Curves 1-4 (copolymer 0.7 mole % HEM A, 0.134% (gram/dl.) solution) had [NCO] 0 [O//] 0 = 102, 1.5 X 102, 10s, and 10u, respectively. Curve 5 (copolymer 2.2 mole % HEM A, 0.047% (gram/dl.) solution) had [IVCO]0 [OH]0 = 10. All solutions have approximately the same [OH]0...

Figure 16. Zimm plot for a styrene-hydroxyethyl methacrylate copolymer (3.8 mole % HEM A) after reaction with hexamethylene diisocyanate, -q0 — rj/rj0 = 0.14. Measurements in toluene at 25°C.

We therefore conclude that the styrene-hydroxyethyl methacrylate copolymers used in this work have a relatively. broad molecular weight distribution and that the effect of increasing hydroxyl content on the properties of dilute toluene solution is to contract the polymer molecule and decrease the polymer-solvent interaction without causing appreciable aggregation by intermolecular hydrogen bonding. 

Most research into the study of dispersion polymerization involves common vinyl monomers such as styrene, (meth)acrylates, and their copolymers with stabilizers like polyvinylpyrrolidone (PVP) [33-40], poly(acrylic acid) (PAA) [18,41],poly(methacrylicacid) [42],or hydroxypropylcellulose (HPC) [43,44] in polar media (usually alcohols). However, dispersion polymerization is also used widely to prepare functional microspheres in different media [45, 46]. Some recent examples of these preparations include the (co-)polymerization of 2-hydroxyethyl methacrylate (HEMA) [47,48],4-vinylpyridine (4VP) [49], glycidyl methacrylate (GMA) [50-53], acrylamide (AAm) [54, 55], chloro-methylstyrene (CMS) [56, 57], vinylpyrrolidone (VPy) [58], Boc-p-amino-styrene (Boc-AMST) [59],andAT-vinylcarbazole (NVC) [60] (Table 1). Dispersion polymerization is usually carried out in organic liquids such as alcohols and cyclohexane, or mixed solvent-nonsolvents such as 2-butanol-toluene, alcohol-toluene, DMF-toluene, DMF-methanol, and ethanol-DMSO. In addition to conventional PVP, PAA, and PHC as dispersant, poly(vinyl methyl ether) (PVME) [54], partially hydrolyzed poly(vinyl alcohol) (hydrolysis=35%) [61], and poly(2-(dimethylamino)ethyl methacrylate-fo-butyl methacrylate)... 

Acyl-oxygen bond in 2-hydroxyethyl methacrylate is activated by the reaction with Ti(0-z -Pr)4 in toluene solution at room temperature to give a pentanuclear aggregate, Ti5(0-z-Pr)9(p-0-z-Pr)(0C2H40)5 [62]. 

Recently [54] a series of IPNs has been synthesized from oligourethane methacrylate (OUMA) and DCEBA by a combined in-situ sequential photo/thermo curing. First, oligourethane diisocyanate, OUDI was s)mthesized by reaction of poly(butylene glycol adipate with toluene diisocyanate at molar ration 1 2. Then, OUMA was synthesized by reaction of OUDI with 2-Hydroxyethyl methacrylate (HEMA) at molar ration 1 2. Next,... 

Methacryloxyethyl Terminated Oligomer. A suspension of 8.0 g of Amberlyst 15 (38.6 mequiv of H ) in a solution of 8.703 g (46.24 mmol) of azelaic acid, 5.004 g (34.70 mmol) of 1,4-cyclohexanedimethanol and 30 ml. of toluene was reacted for 16 hours in a manner similar to the previous example. Then the suspension was cooled, 3.10 g (23.8 mmol) of 2-hydroxyethyl methacrylate was introduced with 0.15 g. of hydroquinone and a partial vacuum adjusted so diat the mixture would reflux at 50-60 C. After 9.3 hours the mixture was cooled to room temperature, diluted, the resin beads filtered and the solution was washed with water. Tht resulting solution showed a tendency to gel on storage at room temperature The polymer was therefore immediately separated from a sample by precipitation with excess methanol. 

The Hquid is basically a methacrylate monomer having a suitable inhibitor to ensure adequate shelf life. A/Ai -Dimethyl-/)-toluidine [99-97-8] is probably the most common polymerization accelerator although A/A/-bis(2-hydroxyethyl)- -toluidine and/or a sulfinate salt, eg, sodium -toluene sulfinate [873-55-2], also maybe used. 

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