The vast scale of mining sites can be hard to comprehend. Everything is oversized, from the mine itself, which can rival the magnitude of Sydney Harbour, to tip trucks rumbling across it on wheels as tall as a human, and ore-carrying conveyor belts that can be tens of kilometres long. 

When one of these conveyor belts gets damaged by the rough ore it is carrying, throwing away such a large piece of rubber is not economically or environmentally optimal. If the belts were repaired, traditionally, a two-part product that had to be mixed just prior to application was used. But this product was time-consuming to apply, and as the conveyor belt is subject to a lot of force, it often only provided a temporary fix.

An innovative research team at 91���� has helped develop a one-part polymer resin product called RubbaFixTM that can quickly and effectively fix the damage. Not only does this avoid replacing a vast length of serviceable rubber belt; the repair product itself is bio-sourced from waste such as vegetable cooking oil, making it an environmentally friendly product, according to Dr Patrice Castignolles, a polymer chemist at Western’s School of Science and Health.

The project began in 2013, when Imatech, a Sydney-based industrial solutions company, approached Dr Richard Wuhrer, Research Manager of Western’s Advanced Materials Characterisation Facility, to test certain properties of RubbaFixTM. Wuhrer soon brought Castignolles and fellow polymer chemist, Dr Marion Gaborieau, into the conversation. 

Castignolles and Gaborieau had previously worked together as part of a team, making and assessing the chemical characteristics of polymers for controlled release delivery systems for anticancer drugs, among other projects. They brought the same skills to the rubber repair product.

The project quickly expanded from testing specific aspects of the new product’s properties to actually helping to develop certain additives for it. The Western team was charged with finding additives to make the repair resin a uniform black colour, and to ensure it had the correct electrical resistivity. “The moving belt creates a lot of electrostatic friction that builds up electricity,” says Castignolles. The effect is like an extreme version of rubbing a balloon against woollen fabric. “You could have an electrical discharge if you are not conducting the charge well enough,” he adds, which has potential to trigger an explosion in the mine. 

The additive the team selected to make the product black showed excellent chemical compatibility with the resin and dispersed homogeneously through it. Moreover, when mixed in the right proportion, the additive also gave the resin the desired electrical resistivity. “Using one additive instead of two is obviously good for cutting down the cost and complexity of manufacturing,” Castignolles says. 

In most environmental conditions, the product the partners developed, offers a permanent damage repair. The next step — and the subject of an ongoing PhD project funded by Imatech — is to cover all conditions. “Mining is carried out from the depths of the Canadian winter, to the Saudi Arabian summer,” explains Russell Eggers, Imatech’s CEO. “The work we are doing is to give us positive product attributes at the extremes of temperature and humidity, as well as in the middle of the range,” he says.

The company’s ultimate aim is to be able to dial up the ideal formulation and produce bespoke products for any environmental conditions, Eggers says. In the interim, a range of off-the-shelf products for different conditions is planned. “We could not do this without the University,” Eggers says. “One of the big benefits of the relationship is that we get access to state-of-the-art capabilities. As a small company we don’t have the capacity to achieve that in any other way,” he says. 

The benefits flow both ways, Castignolles says. “This project is an opportunity for us to teach students what is required to work with industry,” he says. “That is not really something you can do in a lecture.” In addition to the PhD project, Masters students and undergraduates have also been involved, helping test the resin’s resilience in acidic, alkaline and other potentially corrosive conditions. 

“It’s a valuable mutually beneficial relationship,” Eggers concludes. “I personally enjoy working with the University and look forward to commercialising the end-user benefits we are jointly targeting.”    

I have made significant contributions to the understanding of polymerization kinetics and the separation and characterization of polymers, especially branched polymers, polyelectrolytes and polysaccharides.

In terms of polymerization kinetics, using a combination of theory, simulation and experiment, I showed that certain reactions (viz., transfer) with dead polymer chains play a major role in the (radical) polymerization of alkyl acrylates, widely used industrially (in adhesives, coatings and paints). It was published in several seminal papers, including one on benchmark rate coefficients, under the auspices of IUPAC (the interntional governing body in chemistry).

I have made important contributions to the understanding of the separation of polymers by liquid chromatography (particularly size-exclusion chromatography, SEC, also knonw as GPC). I showed that SEC is generally applied in a limited and too often also incorrect way. I showed how these problems could be corrected by proper use of apparent molar masses (e.g. polystyrene -equivalent or pullulan-equivalent molar masses) determined by SEC  in controlled/living polymerization or for the determination of transfer coefficients in radical polymerization. I derived the first rigorous expression for the signals of multiple detectors in SEC, and showed how such data can be processed correctly for complex polymers. I have applied this theory to the first accurate characterization of branched poly(alkyl acrylates), branched glucans and amphiphilic and double-hydrophilic block copolymers (pH-responsive and thermoresponsive) , studies which give considerable insight into the (bio)syntheses of these important classes of polymers. I showed that the local dispersity can be determined using multiple-detection SEC and used to estimate the accuracy of the molecular weight determined by SEC. In the cases  where the accuracy of the moleclar weight is low (e.g. 100 % error), I have shown that hydrodynamic volume distribution can lead to meaningful and accurate information.

I have proposed free solution capillary electrophoresis as an alternative to liquid chromatography in the critical conditions for the separation and characterisation of polyelectrolytes and polysaccharides by their structure such as composition (copolymer) or branching. The method, capillary electorphoresis in the critical condtions, can be used even to characterize soluble fractions in suspensions (no flitration needed) as in the case of gellan gums. it can separate conjugates according tothe functionalization for example chitosan conjugates.

I graduated in Paris, University Pierre and Marie Curie under Prof Jean-Pierre Varion and Prof Bernadette Charleux in 2003. My first post-doc was in the Max Planck Institute for Polymer Reserach, Minaz, in 2004-2005. I was then research Fellows in the Key Centre for Polymer (and) Colloids (KCPC) in the University of Sydney (2005-2006), the Centre for Nutrition and Food Sciences (CNAFS) in the University of Queensland (2006-2008) and the Insitute of Physical Chemistry at the University of Mainz (2009).  In 2010, I joined UWS and the Australian Centre for Research on Separation Science (ACROSS).