(156c) Heat Induced and UV Induced Grafting of Poly(glycidyl methacrylate) on PBT Nonwovens for Bioseparations

Polybutylene terephthalate (PBT) nonwovens were successfully grafted with poly(GMA) using a heat induced grafting (HIG) approach using the thermal initiator benzoyl peroxide. The grafting method resulted in uniform and conformal grafted layers around the PBT fibers that were functionalized as anion and cation exchangers for protein capture. Equilibrium protein binding capacities as high as 200 mg of protein per gram of fabric were observed. The equilibrium binding capacities for protein adsorption to the HIG grafted materials were reached within minutes, compared to UV grafted polyGMA ion exchange fabrics which reached equilibrium protein binding capacities in hours, even though they had the same weight % of grafted layers. However, UV grafted ion exchange nonwoven fabrics were capable of binding between 5 to 7 times more protein per mass of fabric at equilibrium than the HIG materials. It was found that the HIG materials showed a decrease in binding capacity with increased molecular weight of the solute that was much steeper than the drop observed with UV grafted materials. These observations indicate that even though the weight % of grafting is the same for HIG and UV grafting, the HIG grafted layers are significantly thinner and have a lower porosity in solution than the UV grafted brush layers.