Drying of Waterborne Polymer Coatings Studied by NMR Techniques
- Research Group
- Soft Condensed Matter
The student will be based at International Paint in Felling, Gateshead, and will undertake a taught element at the University comprising approximately 25% of the overall programme, with the remaining time being spent on the research project. The majority of the experimental work will take place internally at International Paint, where the student will prepare polymers and paint test materials and will apply light scattering techniques. Some experiments will use the specialist gradient-field NMR facilities of the University’s Soft Matter Physics Group, which has developed expertise in the study of polymer colloids over the past 15 years.
International Paint is the name of AkzoNobel’s Marine & Protective Coatings (M&PC) business unit, which encompasses operations in the marine, protective coatings and yacht paint markets. International Paint has a proud history stretching back to 1881 and currently has operations in 54 countries worldwide and more than 5,500 employees.
International Paint is part of the AkzoNobel company. With headquarters in Amsterdam, the Netherlands, AkzoNobel supplies a huge range of paints, coatings and specialty chemicals - pro forma 2009 revenue totalled €13.9 billion. In fact, AkzoNobel is the largest global paints and coatings company and is a major producer of speciality chemicals supplying industries worldwide with quality ingredients for life’s essentials.
The company operates under an ethos of environmental and social responsibility and has been recognized as one of the industry leaders on the prestigious Dow Jones Sustainability World Indexes (DJSI), reflecting the company’s commitment to improving its sustainability performance.
The student will spend time working at the Technology Centre (TC M&PC) at International Paint’s main research and development site at Felling in Gateshead in the north east of England. The Technology Centre undertakes longer term research projects on behalf of the company’s business units aimed at new product development and new technology evaluation and development. The group is equipped with state-of-the-art coatings technology equipment and facilities and is located in a new, purpose-built facility on the Felling site.
- Techniques used
One of the main experimental techniques will be magnetic resonance profiling, which is a non-invasive method of measuring the distribution of water in a coating. The technique applies a magnetic field gradient across the coating, so that each position has a different magnetic resonance frequency, which encodes the position. The strength of the signal is proportional to the local water concentration. There is a permanent magnet with shaped pole pieces at the University of Surrey, called GARField, which has been particularly designed to study coatings.
The project will aim to correlate the final film properties with the physics of drying and film formation as described in recent models. The relationship of these parameters to paint industry tests such as dry track and open time as well as the final film quality, will provide valuable information. Coatings testing using a recently acquired Horus film formation analyser will also be of interest.
- Student will require
The ideal candidate will have a good undergraduate degree (first or upper-second class honours) or a Master’s degree in a subject with some physical sciences content (e.g. chemistry, physics, materials science, or nanotechnology). The candidate will need to demonstrate good practical and analytical skills. Some knowledge of NMR would be advantageous, but training will be provided. Good written and presentation skills are essential, as is the ability to work as a team member.
The coatings industry is under significant regulatory pressure to reduce the amount of solvent emitted to atmosphere as a result of the application and drying of its products. One of the principal routes for reducing organic-solvent emission is through the use of waterborne coatings. This type of coating, which is deposited from a colloidal dispersion of polymers in water (called a latex), now finds widespread use in many domestic and industrial applications. A major factor limiting their use is drying under conditions of low temperature and/or high humidity (below 5 °C and above 80% RH).
What is the problem to be addressed?
• Drying under cold and/or humid conditions leading to incomplete coalescence, poor film integrity, mechanical properties, water resistance, etc;
• Drying at high ambient temperatures leading to poor film appearance or cracking;
• The inability of waterborne coatings to disguise imperfections in the underlying substrate (compared with solvent-borne coatings and some waterborne coatings based, for example, on polyurethane dispersions). Solving this problem may require some study of binder flow after drying.
- Funding source
Funding will be provided by Surrey's Industrial Doctorate Training Centre and by International Paint.
- Funding amount
- £19,500 p.a. salary
This Engineering Doctorate (EngD) project will study the drying of waterborne coatings using advanced techniques of nuclear magnetic resonance (NMR) profiling and imaging in parallel with novel methods of light scattering. The project aims to understand the factors that affect the water loss and spatial distribution in films deposited from polymer colloids in water in the form of a latex dispersion. Results will be interpreted with the aid of recent models of the drying process. Materials will be provided by International Paint, which is a world leader in marine coatings.
Course fees will also be paid by the studentship. Significant funds are available for travel and conference attendance.