Synthesis and structural characterization of dendritic-linear PMA-APM-r-PS copolymers for a self-assembled microporous matrix

Abstract

A set of dendritic-linear copolymers, poly(maleic anhydride-grafted-3,3′-dimethyl-(4-aminophenylazanediyl)bis(2-methylpropanoate))-random-polystyrene (PMA-APM-r-PS), was successfully prepared by copolymerization of the novel dendritic macromonomer, 4-(4-(bis(3-(4-(bis(3-methoxy-2-methyl-3-oxopropyl)amino)phenylamino)-2-methyl-3-oxopropyl)amino)phenylamino)-4-oxobut-2-enoic acid (MA-APM), with styrene monomer. The dendritic MA-APM macromonomer dendron 3,3′-dimethyl-(4-aminophenylazanediyl)bis(2-methylpropanoate) (APM) was then grafted by using the divergent growth method. FTIR, 1H NMR, and 13C NMR spectra were used to identify the structures of the dendron, the dendritic macromonomer, and the dendritic-linear PMA-APM-r-PS copolymer. Furthermore, microporous dendritic-linear PMA-APM-r-PS copolymer films were prepared by using solvent-induced phase separation at room temperature. We investigated the phase separation behavior and morphological structures of the dendritic-linear copolymer film as functions of dendritic GMA-HPAM segments in the content using SEM. Self-assembly of the dendritic-linear PMA-APM-r-PS copolymer in the MG2-X system, which represented the second generation dendron containing X wt % of the dendritic MA-APM segment, resulted in submicron phase segregation. Interestingly, the submicron phase segregation morphology of the MG2–43 sample presented a uniform size distribution of ordered-array structures. The results of this study demonstrate that controlling the appropriate macromonomer content via the grafting of a three-dimensional structure results in a self-assembly process that is capable of providing an ordered-array microporous morphology in a polymer film. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3290–3301, 2010