Double Networks Based on Amphiphilic Cross-Linked Star Block Copolymer First Conetworks and Randomly Cross-Linked Hydrophilic Second Networks

• DOI: 10.1021/acs.macromol.5b02490
• Publication Date: 2016-02-25T13:59:34Z
• Authors: Maria Rikkou-Kalo...; Elina N. Kitiri; Costas S. Patrickios; Epameinondas Leon...; Marios Constantinou; Georgios Constant...; Xiaohan Zhang; Christine M. Papa...
• Keywords: Aqueous photopolymerization; Amphiphilic polymethacrylate conetwork (APCN); X ray scattering; Star block copolymer; Double network (DN); Hydrophobicity; Phase separation; Mechanical properties; 02 engineering and technology; Strain; Ethylene; Polymer blends; 2-(dimethylamino)ethyl methacrylate; Stresses; Group transfer polymerization; Hydrophilicity; Ethylene glycol; Hydrophobic content; Photopolymerization; Polyacrylates; Microphase separation; Mechanical Engineering; Monomers; Ethylene glycol dimethacrylate; Block copolymers; Amides; Short range ordering; Engineering and Technology; Hydrophobic monomers; 0210 nano-technology

This study presents the preparation and characterization of double networks (DN) based on a first amphiphilic polymethacrylate conetwork (APCN) and a second polyacrylamide network. The APCN first network comprised interconnected “in–out” star copolymers of 2-(dimethylamino)ethyl methacrylate (DMAEMA, hydrophilic ionizable monomer) and 2-ethylhexyl methacrylate (EHMA, hydrophobic comonomer) or lauryl methacrylate (LauMA, second hydrophobic comonomer), synthesized using group transfer polymerization, following one-pot, sequential, monomer, and hydrophobic cross-linker (ethylene glycol dimethacrylate, EGDMA) additions. The second network was prepared by the aqueous photopolymerization of acrylamide (AAm) at two different concentrations, 2 and 5 M, and N,N′-methylenebis(acrylamide) cross-linker in the presence of the fully ionized (via HCl addition) APCN. After synthesis, all DNs and single (first and second) (co)networks, equilibrium-swollen in water, were characterized in terms of their mechanical propertie...