Self-Assembling Microporous Matrix from Dendritic−Linear Copolymers Based on a Solvent-Induced Phase Separation Mechanism

Abstract

A set of dendritic−linear copolymers, poly(glycidyl methacrylate-grafted-dimethyl 3,3′-(4-hydroxyphenylazanediyl)bis(2-methylpropanoate))-random-polystyrene (PGMA-HPAM-r-PS), were successfully prepared by copolymerization of the novel dendritic macromonomer dimethyl 3,3′-(4-(2-hydroxy-3-(methacryloyloxy)propoxy)phenylazanediyl)bis(2-methylpropanoate) (GMA-HPAM) and a styrene monomer. The dendritic GMA-HPAM macromonomer dendron 3,3′-(4-hydroxyphenylazanediyl)bis(N-(2-aminoethyl)-2-methylpropanamide) (HPAM) was then grafted using the divergent growth method. 1H NMR and 13C NMR spectra were used to identify the structure of the dendritic−linear GMA-HPAM-r-PS copolymer. Microporous dendritic−linear PGMA-HPAM-r-PS copolymer films in this system were prepared by using solvent-induced phase separation at room temperature. The phase separation behavior and the morphological analyses of the dendritic−linear copolymer film as functions of dendritic GMA-HPAM segment contents were investigated by using AFM, TEM, and SEM. Self-assembly of the dendritic−linear PGMA-HPAM-r-PS copolymer in a G2−37 system containing 37 wt % of the dendritic GMA-HPAM segment, which exhibits the second generation dendron, showed submicrometer phase segregation with the main chain styrene segment. Interestingly, the submicrometer phase segregation morphology of the G2−37 sample represented a uniform size distribution of the hexagonally ordered structures. Our results prove that controlling the appropriate macromonomer content by grafting a three-dimension structure results in self-assembly and provides a honeycomb ordered microporous copolymer matrix.