Porogen Type Research Articles

Characterization of crosslinked, macroporous, monosized polymer particles

Macroporous, monosized poly(meta-divinylbenzene) and poly(para-divinylbenzene) beads have been prepared by the two-step activated swelling method with toluene or 2-ethylhexanoic acid as pore-forming agents. The type of divinylbenzene isomer as well as the type of porogen has a large effect on both physical and chemical properties of the monodisperse beads. Large pores are obtained with 2-ethylhexanoic acid as porogen while beads prepared in the presence of toluene consist of only small pores and exhibit a shrinking behavior upon drying. The beads have considerable amounts of residual vinyl groups at the end of polymerization, as determined by bromination and Fourier transform IR analysis. The morphology and texture of the particles have been investigated by scanning electron microscopy and atomic force microscopy. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 152–169, 2000

Effects of experimental variables on the synthesis of porous matrices

Macroporous beads, poly(ethylene glycol dimethacrylate-co-acrylic acid) [poly(EGDMA-co-AAc)], and poly(ethylene glycol dimethacrylate-co-hydroxyethyl methacrylate) [poly(EGDMA-co-HEMA)] were prepared by the suspension polymerization technique in the presence of a porogen agent. Different experimental conditions such as amount of initiator, porogen type, and temperature were studied to optimize the polymerization systems. These hydrophilic copolymers were characterized by IR spectroscopy, scanning electron microscopy, specific surface area, and swelling in water. A new parameter, H, defined as the ratio between the equilibrium weight swelling ratio (q w ) and equilibrium volume swelling ratio (q v ), allowed to select the reaction conditions from which matrices with high capacity of water sorption and low stretching degree were reached.

The influence of porogen type on the porosity, surface area and morphology of poly(divinylbenzene) PolyHIPE foams

Download options Please wait... Article information DOI https://doi.org/10.1039/B003596N Article type Paper Submitted 03 May 2000 Accepted 10 Aug 2000 First published 12 Sep 2000 Download Citation J. Mater. Chem., 2000,10, 2466-2471 BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions The influence of porogen type on the porosity, surface area and morphology of poly(divinylbenzene) PolyHIPE foams N. R. Cameron and A. Barbetta, J. Mater. Chem., 2000, 10, 2466 DOI: 10.1039/B003596N To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page. If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given. If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page. Read more about how to correctly acknowledge RSC content. Search articles by author Neil R. Cameron Andrea Barbetta

Preparation by suspension polymerization of porous beads for enzyme immobilization

AbstractPorous beads have been prepared by suspension polymerization of acrylic monomers and divinyl benzene in the presence of a porogen. The porosity varies greatly with the polymer composition, with the amount and type of porogen and with the conditions for the preparation. The enzyme binding capacity and activity has been determined for a lipase. The best results are found for crosslinked poly(methyl methacrylate) beads while other polyacrylates are less effective. Compositions based on poly(methacrylic acid) are not suitable for enzyme binding.

Protected porous polymers

This study was designed to answer the question whether the chromatographic performance of porous polymers — serving here as a model system for pressure-sensitive separation media of relatively large mass transfer resistance — could be improved (a) by imposing on them a chromatographically favorable, extrinsic macrostructure and (b) by protecting that macrostructure against physical deformation. Packed-column gas chromatography was used as the test system.Protected porous polymers (PPP's) were synthesized from pure divinylbenzene (DVB) inside conventional diatomaceous supports, using various amounts and types of porogens. The non-extractable polymer loads ranged from 10 to 40% and conformed to (i.e. formed layers on) the diatomaceous macrostructures. The best plate numbers were in excess of 4000/m on a 100/120 mesh Chromosorb W base. The mass transfer resistance of these materials was very low and permitted high flow rates. The PPP's could be used up to 280 °C and did not appear to suffer deformation; in fact, the polymer appeared to shield the diatom supports from abrasion. The data indicate that the porous polymer deposits had relatively high specific surface areas, and produced a relatively large value for the free energy of sorption per methylene group, as compared with conventional porous polymer beads. Otherwise, protected and unprotected types of porous polymers had similar chromatographic characteristics. Keywords: porous polymer, poly(divinylbenzene), gas chromatography, protected polymer, diatoms.