Polymeric resins, covalent immobilization

One way to use surfactants in synthesis is to immobilize them. For example surfactant moieties can be bound covalently to a solid polymeric support [176]. Alternatively a surfactant or a hydrophobic cation can be supported on a solid support such as an ion-exchange resin [106] or silica gel [177]. 

A series of close-to-spherical styrene/DVB resins of varying particle size and pore diameter were employed as supports for non-covalent adsorptive attachment of CALB by hydrophobic interaction. The effect of matrix particle and pore size on CALB i) adsorption isotherms, ii) fraction of active sites, iii) distribution within supports, and iv) catalytic activity for s-CL ring-opening polymerizations and adipic acid/l,8-octanediol polycondensations is reported. Important differences in the above for CALB immobilized on methyl methacrylate and styrene/DVB resins were found. The lessons learned herein provide a basis to others that seek to design optimal immobilized enzyme catalysts for low molar mass and polymerization reactions. 

Blechert et al. described the covalent bonding of Grubbs and Hoveyda-Blechert type metathesis catalysts to a support material via the N-heterocyclic carbene (NHC) ligands [33-35]. They used a Merrrfield-type resin as the polymeric backbone of the immobilized catalysts (cf. Figure 3a,b)). 

---