Functional macroporous polymers have been synthesized from copolymers of trimethylolpropane trimethacrylate (TRIM) and glycidyl methacrylate (GMA). The accessibility of the epoxy groups has been investigated by reaction with dialkylamines and diamines of different chain lengths. The obtained yield of reacted amine was approximately 80% for small molecules. The yield, and accessibility, decreased when the chain length or bulkiness of the reagent increased. The swelling ability in water of the functional polymers increased compared with the original copolymer.

SYNOPSISTrimethylolpropane trimethacrylate (TRIM ) was homopolymerized and copolymerized with methyl methacrylate (MMA) , glycidyl methacrylate (GMA) , and acrylamide ( AA) , respectively, in various solvents and at various temperatures. For comparison, poly (styreneco-divinyl benzene) [ poly (S-co-DVB) ] gels were selected. The mechanical stability was measured by compression of the swollen gels. The porogen served as swelling agent. The compression moduli increased with increasing TRIM concentration in the polymerization. The compression moduli of poly (TRIM) could be increased by copolymerization with low concentrations of comonomer. Low polymerization temperature decreased the mechanical strength of poly (TRIM ) . A good solvent increased the compression modulus. TRIM-based gels were a t least as mechanically stable as were poly ( S-co-DVB ) gels. I N T R O DU CTI 0 NPorous materials used as the stationary phase in high-performance size-exclusion chromatography (HPSEC) should be mechanically stable. To achieve fast separation, high flow rates through the column are necessary. Because an increase in flow rate increases the pressure drop over the column, a compromise among particle size, flow rate, and mechanical stability of the gel structure is necessary.Conventional polymer materials used as the stationary phase in SEC and HPSEC based on dextran, acrylamide-bisacrylamide, 2*3 and agarose show good separation properties at low flow rates. Styrene-co-divinyl benzene-based have much better mechanical stability. Each material has an optimal flow rate vs. pressure drop curve that depends on the particle size. Above a certain flow rate, the pressure increases asymptotically and the column material "collapses." This is due to deformation of the gel particles and "plugging" of the void spaces.The mechanical properties of porous materials has been investigated by the resonance method6-8 (dynamic mechanical measurements) and by * To whom correspondence should be addressed.Journal of Applied Polymer Science, Vol. 45, 1995-2004 (1992) EXPERIMENTAL PretreatmentThe monomers trimethylolpropane trimethacrylate (TRIM) (technical quality containing more than 98% TRIM, Merck) , methyl methacrylate (MMA) , (pure, Fluka) , glycidyl methacrylate (GMA) , (technical quality, Fluka) , styrene ( S ) (pure, Merck) , and divinyl benzene (DVB ) (60% isomers and 35% ethyl vinyl benzene, Merck) were passed through a column of basic aluminum oxide to remove inhibitors. PolymerizationThe monomers were dissolved in various porogens: toluene (maximum impurities 0.3%, Riedel-de 1996Riedel-de 1996 SCHMID, WALENIUS, AND FLODIN Haen), ethyl acetate (maximum impurities 0.005% Pronalys analytical reagent), p -xylene (pure, Merck), and heptane (pure, Merck). The solution polymerizations were initiated with a,a'-azoisobutyronitrile ( AIBN ) (analytical grade, Fluka) after purging with nitrogen for 1 min. Cylindrical gel pieces were obtained after polymerization for 8 h in vials with rolled rims and flat bottoms (34 X 24 mm 4). For mor...

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