Robac SRM102: Questions and Answers

What is Robac SRM102?
Robac SRM102 is a multifunctional accelerative curative molecule which has been designed by Robinson Brothers' Robac Technology team to be utilised during the process of polychloroprene vulcanisation.

How does this differ from what is currently available?
At present, the option that provides the best curative properties is ethylene thiourea (ETU), but this has been classified as a CMR product - Carcinogenic/Mutagenic/Toxic for Reproduction - under the European Union's (EU's) REACH regulation. It has been added to the List of Substances of Very High Concern (SVHC) and as a result, is likely to be subject to restrictions on its use in the near future. The rubber industry has been searching for a viable alternative for some time, but the accelerators produced have generally tended to be too expensive to be used in the majority of applications or have failed to match ETU's curing characteristics. Robac SRM102 is different in that it is a safe alternative and industry validation trials conducted by the SafeRubber Consortium have proven the product has equal or better curative properties when compared to ETU.

What is the SafeRubber Consortium?
This comprises 12 key stakeholders keen to address issues facing the European synthetic rubber community, including industry associations, small and medium-sized enterprises (SMEs) and research and technological development (RTD) partners. In total, these partners covered five nations and represent more than 360,000 businesses, with a combined turnover of more than €3.2 billion (£2.55 billion) across Europe.

When did the process begin?
Robinson Brothers became involved with the search for a compound to replace ETU in 2007 and applied for funding under the EU's Framework 7 programme. This is a prestigious scheme that provides financing for projects that produce "European added value". The application process is highly competitive and proposals are assessed for their ability to strengthen the European scientific and technological base, and the ways in which they will boost the EU's performance international markets. In 2010, the company was awarded the esteemed grant, which facilitated further progress.

How was Robac SRM102 developed?
Before it was possible to create an alternative to ETU, it was first necessary to understand how the accelerator works during the polychloroprene vulcanisation process. As a result of the Framework 7 grant, Robinson Brothers was able to utilise its long-standing relationship with local educational institutes to sponsor PHD students from Aston University to conduct this research, which then facilitated the development of an alternative. Dr Keith Berry was one of these students and his findings have been published and exhibited at the Institute of Materials' RubberCon 2014 exhibition.

Following the discovery of a new polychloroprene vulcanisation mechanism, the Robac Technology team was able to theoretically propose 20 molecules that could be used as alternatives to ETU. These were then subjected to Quantitative Structure Activity Relationships (QSAR) screening, which indicated 12 were non-CMR and so suitable for further development.

The proposed molecules were synthesised and small-scale testing was conducted. Robac SRM102 proved to be the best candidate and was scaled-up to one kilogramme quantities for industrial validation trials. These trials were conducted by members of the SafeRubber Consortium and showed Robac SRM102 to have curative characteristics equal or better than ETU.

Robac SRM102 has been manufactured by Robinson Brothers on a 500kg production scale and samples will be available as a polymer bound masterbatch in Q3 of 2014.To find out more, please contact [email protected]