Abstract
A robust approach for modification of TiO2 nanoparticles with polymer brushes by atom transfer radical polymerization (ATRP) is presented. TiO2 surface was first coated with polydopamine (PDA) followed by immobilization of an ATRP initiator, α-bromoisobutyryl bromide (BiBB). Poly(methyl methacrylate) (PMMA) and poly(butyl acrylate) (PBA) were then grafted from the PDA-modified TiO2 of different size (25 and 300 nm) in DMF at room temperature via supplemental activator reducing agent (SARA) ATRP using only 100 ppm of the copper catalyst. Hybrid core-shell particles with high organic contents (40–88 wt%) and grafting densities (0.16–0.25 nm−2) were obtained. Reaction conducted in the presence of sacrificial initiator confirmed excellent control over the polymerization and produced PMMA and PBA with narrow molecular weight distributions (Mw/Mn < 1.25). Obtained particles were tested as lubricating additives in pipe dope compositions. Addition of polymer-grafted TiO2 to the base grease resulted in a reduced coefficient of friction (COF) and wear over uncoated TiO2 as revealed by reciprocating pin-on-disc tests. The model pipe dopes with PMMA-grafted particles were found to perform on par with commercial American Petroleum Institute (API) dope.
Original language | English |
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Pages (from-to) | 291-296 |
Number of pages | 6 |
Journal | European Polymer Journal |
Volume | 106 |
DOIs | |
Publication status | Published - Sept 2018 |
Funding
This research was performed within the framework of the 4TU.High-Tech Materials research program: ‘New Horizons in designer materials’ (www.4tu.nl/htm). We would like to thank Shell Global Solutions BV for giving us the opportunity to publish our work and acknowledge the support of Shell Lubricants Hamburg in preparing the base greases.
Keywords
- Grafting from
- Lubrication
- Nanocomposites
- Polydopamine
- SI-ATRP
- Titanium dioxide
ASJC Scopus subject areas
- General Physics and Astronomy
- Organic Chemistry
- Polymers and Plastics
- Materials Chemistry