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Author(s): |
Teng-teng Hou, Key Lab of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science,
Cheng-bo Zhang, Key Lab of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science,
Pei-pei Zhang, Key Lab of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science,
You-liang Zhao, Key Lab of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, |
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Abstract: |
A trifunctional initiator 3-hydroxymethyl-5-prop-2-ynyloxybenzyl-2-bromo-2-methylpropionate (HPB) was synthesized and used for synthesis of alkyne-mid-functionalized diblock copolymers by sequential ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). Diblock copolymers were comprised of polycaprolactone (PCL) and other segments such as poly (methyl methacrylate), poly (tert-butyl acrylate), poly (butyl acrylate) and polystyrene (PSt). Click reaction between alkyne-functionalized block copolymers and azide-modified silica particles was performed to obtain silica particles grafted with V-shaped copolymers. Diblock copolymers were characterized by GPC and 1H NMR, and silica-polymer hybrids were characterized by FT-IR, TGA, DSC, SEM and TEM. The hybrid materials comprising amphiphilic PCL-PAA block copolymers could be efficiently dispersed in water and organic solvents. As compared with their linear precursors, diblock copolymers grafted onto silica particles exhibited significantly decreased melting point and glass transition temperature, which could be ascribed to relatively weak interactions between polymeric chains and thin film thickness (less than 20 nm) of grafted polymers at the surface of solid supports originating from a mezzo grafting density (0.05-0.08 chains/nm2).
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