SNAP - Innovative coatings for paper (2008 - 2011)

Production and characterization of imidised styrene-maleic-acid-anhydride (SMI) nano particles

This project runs in cooperation with the company Topchim that is responsible for the production of imidised styrene-maleic-acid-anhydride (SMI) nano particles. These SMI-particles are produced in a stable water based dispersion and are applied mainly in the paper industry to make the paper glossier.

This project aims – amongst other things- at getting a better understanding of the imidisation reaction in order to improve the stability of the dispersion, as well as the reproducibility of the shape and size of the nano particles.  The average diameter aimed for is 50 nm.


Figure 1: the imidisation reaction of styrene-maleic-acid-anhydride (SMA)

In order to achieve this, a reaction at lab scale is performed under varying conditions (quantity of NH3, temperature, pressure) and with several types of SMA, differing in molecular weight and composition.

The chemical properties of the different types SMA and SMI are investigated with different techniques, such as: Differential Scanning Calorimetry (DSC), Gel Permeation Chromatography (GPC), Thermogravimetric Analysis (TGA), Fourier Transform Infrared Spectroscopy (FTIR), RAMAN Spectroscopy en Nuclear Magnetic Resonance (NMR) Spectroscopy.

Topchym is also responsible for the production of different types of oil-filled SMI dispersions, especially with vegetable oils that play an important role because of their environment-friendliness. These oil-filled nano-particles provide the paper with an even better gloss and hydrophobia.

Final aim is to replace the paraffin waxes that are currently widely applied in the paper industry by this more environment-friendly alternative. Additionally the maintenance of the paper production machines will also be simplified, as well as the production of pulp out of paper that is treated with oil-filled SMI-coatings.

Supported by: IWT

Duration: 09/2008 - 08/2011

Contact: Prof. Dr. Paul Kiekens