Effects of composition and polymerization conditions on crosslinked polymer supports based on N ‐acrylyl pyrrolidine and N , N ‐dimethyl acrylamide for peptide synthesis

Poly( N ‐acrylyl pyrrolidine‐co‐ N , N ′‐bis(acrylyl) 1,2‐diaminoethane‐co‐ N ‐Acrylyl 1,6‐diamino hexane HCl) with 2,5,8,11,12,15, and 20% degrees of crosslinking (DC) and poly‐( N , N ′‐dimethylacrylaminde‐co‐ N , N ′‐bis(acrylyl) 1,2‐diaminoethane‐co‐ N ‐acrylyl 1,6‐diamino hexane HCl) with 2,5,10, and 15% DC have been synthesized in an entirely beaded form by reverse‐phase suspension polymerization. The monomer‐to‐water ratio was kept constant for all these polymers. With the exception of 2% crosslinked resins in the PAP and PDMA groups, all the resins exhibited favorable swelling properties in solvents normally used for peptide synthesis and the percent incorporation of the first amino acid residue was close to 100 for DC of up to 20%. This is explained as due to the flexible and polar characteristics of the crosslinking agent, N , N ′‐bis(acrylyl) 1,2‐diaminoethane. Between 5 and 20% DC the degree of swelling of the resins changes only slightly with increasing DC. This effect of DC on the swelling and percent incorporation of the first amino acid residue is more favorable for peptide synthesis than in the case of divinyl benzene crosslinked poly(styrene).