Porous copolymers

PolyHIPE materials have also been prepared by polycondensation in high internal phase emulsions [153]. Thus, a resorcinol-formaldehyde (RF) porous copolymer was synthesised from an o/w HIPE of cyclohexane in an aqueous solution of resorcinol, formaldehyde and surfactant. Addition of an acid catalyst to the emulsion, followed by heating, resulted in copolymerisation. Other systems prepared included urea-formaldehyde, phenol-formaldehyde, melamine-formaldehyde and a polysiloxane-based elastomeric species. 

Sydor, R. Pietrzyk, D.J. Comparison of porous copolymers and related adsorbents for the stripping of low molecular weight compounds from a flowing air stream. Anal. Chem.,... 

Abstract Porous copolymers have been prepared by suspension-emulsion polymerization of divinylbenzene with styrene or some methacrylic monomers di(methacryloyloxymethyl)naphthalene, methacrylic ester of p,p -dihydroxy-diphenylpropane diglycidyl ether, and dimethacrylglycolethylene in the presence and absence of chemically modified fillers (fumed silicas with grafted methyl and silicon hydride groups). The results of investigations of the unfilled and filled polymeric systems by IR and 13C NMR spectroscopies combined with AFM are presented. 

Keywords porous copolymers, divinylbenzene, styrene, methacrylic monomers, chemically modified silicas, fillers... 

B. Gawdzik and J. Osypiuk, Reversed-phase high-performance liquid chromatography on porous copolymers of different chemical structure, J. Chromatogr. A 898(1), 13-21 (2000). 

B. Gawdzik and T. Matynia, Thermal properties of porous copolymers of 1,4-di(metha-cryloyloxymehyl)naphthalene with divinylbenzene, React. Polym. 5, 197-202 (1987). 

In the area of hydrometallurgy, Cu2+ and Au(CN)2 salts could be selectively sorbed from aqueous solutions with polyacrylamide-based copolymers containg aminoguanidine units. Porous copolymers of acrylonitrile, divinylbenzene and vinylacetate were derivated with aminoguanidine.15 Alternatively, methacrylate-based copolymers were transamidated with the same base16 to give polyacrylamide-type resins (Figure 11). 

Haeupke et al. found that gel and half-porous copolymers may become porous after being modified with a second monomeric phase containing an inert diluent. Such modified copolymers are called double porous copolymers (Haeupke et al. ) or hybrid copolymers (Barrett and Clemens ). 

Recent developments in coating technology have enabled cross-linked styrene divinylbenzene porous copolymers to be successfully immobilised on the silica wall of a capillary column. These PLOT columns have similar retention properties to the packed column equivalents but with higher resolution. PoraPLOT columns with Porapak Q, S or U stationary phases are general purpose columns suitable for the analysis of C) -C4 hydrocarbons, chlorofluorocarbons and atmospheric pollutants [35,36]. 

Sydor, R., Pietrzyk, D. Comparison of Porous Copolymers and Related Adsorbents for the Stripping of Low Molecular Weight Compounds from a Flowing Air Stream, Anal. Chem. 50,1842(1978)... 

Hradil, J., Kfivakova, M., Stary, P, and Coupek, J. Chromatographic properties of macro-porous copolymers of 2-hydroxyethyl methacrylate and ethylene dimethacrylate. J Chro-matogr, 79, 99-105 (1973). 

K., Preparation of Bimodal Porous Copolymer Containing P-Cyclodextrin and Its Inclusion Adsorption Behavior. J. Appl. Polym. Sci. 2010,118, 2176-2185. Zhao, W. Fierro, V. Pizzi, A. Celzard, A., Bimodal Cellular Activated Carbons Derived from Tannins. J. Mater. Sci. 2010, 45, 5778-5785. 

B. N. Kolarz, Ion Exchangers XIX. Some Properties of the Carboxylic Cation Exchangers Obtained by Intermesh Polymerization of Methacrylic Acid into Styrene and Divinylbenzene Porous Copolymers, /. Polym. Sci. 47C, 197 (1974). PS/PMA IPNs. Both polymers crosslinked with DVB. Effect of porosity of network I. Effect of crosslink density of network I. Ion exchange properties. 

The porous copolymer volume often is higher than the liquid phase volume (consisting of monomers and inert medium) because the network monomers adsorption on the swollen network determines the network s volume expansion. 

Mohamed Mohamed H., and Wilson Lee D. Porous copolymer resins Tuning pore structure and surface area with non-reactive porogens. Nanomaterials. 2 no. 2 (2012) 163-186. 

Synthetic active carbons are a new type of carbon sorbent prepared from porous copolymers and spherical granulated resins by their pyrolysis and subsequent vapour-gas activation. The sorbents obtained have improved properties including increased mechanical strength as well as a highly specific pore structure. 

---