A feasible method of preparation of block copolymer latex films with stable microphase separation structures

作者：Yang Lei^*; Sun Peng; Yang Hai; Qi Dongming; Wu Minghua

来源：Progress in Organic Coatings, 2014, 77(2): 305-314.

DOI：10.1016/j.porgcoat.2013.10.004

• RAFT polymerization
• Miniemulsion polymerization
• Structured latex
• Nanostructured latex film
• Mechanical properties

RAFT (reversible addition-fragmentation chain transfer) miniemulsion polymerization was engaged to engineer latex particle morphology. With this approach, a macromolecular amphiphilic RAFT agent with epoxy groups was synthesized that assembled onto the surface of monomer mini-droplets. It caused the polymer chains to grow inwards gradually in particles as polymerization proceeded. The batch polymerization of n-butyl acrylate (BA) followed by addition of styrene (St) led to the formation of PBA-b-PSt diblock copolymer shell-core latex, where epoxy groups were enriched on the particle surface. The shell-core ratio was varied feasibly by changing the mass of St. When the structured latexes were dried, epoxy groups underwent efficient curing reactions triggered by a thermal-latent curing agent (dicyandiamide) in a controlled manner, leading to the formation of bonded PBA blocks connecting the PSt blocks in adjacent particles. Mechanical tests show that the films behaved like ductile materials, whose modulus and elongation at break were functions of copolymer compositions. Furthermore, curing reaction was a very robust method of preserving film morphology which correlated well with that observed for the latex particles. The results demonstrated a feasible method of preparation of latex films with stable microphase separation structures and thus improved mechanical properties.

• 出版日期2014-2
• 单位浙江理工大学