Dennis left school at 16 to take up a position with the Distillers Company in Barry Dock, Cardiff and pursued his education at night school. After obtaining an HNC in chemistry he was accepted at the University of Wales, Cardiff from which he gained his Honours Degree in Chemistry and subsequently his PhD in Physical Chemistry in 1959. He was accepted for a two year postdoctoral fellow at Cornell University, Ithaca from which he gained an academic appointment at the then Royal College of Advanced Technology in 1961.
He remained at the University of Salford until 2003, being awarded his chair during the late 1990s. Dennis was 'instrumental' in bringing mass spectrometry to Salford and, during the 1970-80 period, his research at Salford focussed on this and on flash photolysis of gas-phase systems such as hydrocarbons and petroleum additives such as tetraethyl tin. His interest in the application of mass spectrometry to pyrotechnic systems enabled him to establish an international reputation within the field of time-of-flight mass spectrometry, studying the kinetics of fast reactions, which during the 1980's he applied to studies of fire retardant systems.
His work during this time was marked by active publication. of his research including a number of advanced texts, not least one of the few recent studies of bromine "Bromine Compounds: Chemistry and Applications" co-authored and co-edited with Dr Brian Iddon and Dr Basil Wakefield in 1988.
His association with the University of Bolton started in 1984 when he and Professor Richard Horrocks agreed to collaborate, initially within the flame retardant textile field. This enabled a number of final year Bolton students to transfer to the Salford MSc by Research prior to continuing to a PhD while undertaking research at Bolton. Under this arrangement, industrial interest and funding was attracted, which was helped by the implementation within the UK of the requirement for cigarette ignition resistance of furnishing fabrics following the Manchester Woolworth's fire in 1979, plus the international requirement for fire resistant seating in all commercial aircraft precipitated by the 1985 Manchester Airport fire.
Sponsorship from the then Albright and Wilson, Ciba, Schill & Seilacher and Courtaulds companies followed as did a Research Council full-time research project and research student grants. During this period the combined Salford-Bolton group produced papers on the quantification of textile burning behaviour as well as on investigations of the associated mechanisms when different flame retardants were present; many of these have stood the test of time and are referred to still by researchers 25 years later.
During the 1990 period, as the reputation of the Bolton-Salford collaboration grew, Dennis was at the forefront of founding the UK Fire Chemistry Technical Interest Group under the aegis of the Society of Chemical Industry and he was chairman for the first 10 years or more. This group involved both universities and industry and met twice yearly, at Easter and as near to the 5th of November as possible - during this period meetings were held across the UK, and the reputation of the Group enabled Dennis to attract the biennial European Fire Retardant Polymer Materials conference to Salford and the UK for the first time in 1995, to Greenwich in 1999 and to Bolton in 2007. His SCI work included membership of the Macro Technical Interest Group and the Liverpool and North West Regional Interest Group, as well as the SCI Technical Development Committee (2000 and 2009) and SCI Council (now Board of Trustees) (2000 -2005). More recently, he revitalised the SCI's former UK Fire Chemistry Group into its current form, the Fire Materials Technical Interest Group.
In 2003, the University of Salford closed its Department of Chemistry and Applied Chemistry which meant that Dennis, although semi-retired by then, would be redundant along with his former student and staff colleague Richard Hull and experimental officer, John Milnes. A transfer of the group to the University of Bolton was secured with the assistance of funding from HEFCE (£100,000) to enable a new fire laboratory to be built. Thus, Dennis became a Professor at the University of Bolton and remained so until his unexpected death.
At Bolton the enlarged group prospered and extended its research interests across the whole materials area including fibres, textiles, polymers and composites. During this time, Dennis supervised Bolton students and postdoctoral fellows, contributed to two Research Assessment Exercises and published many papers, and worked with Professor Horrocks to produce their two co-edited texts in 2001 (Flame Retardant Materials) and in 2008 (Advances in Flame Retardant Materials).
He will be remembered across the world of fire science for many years to come as his 200 scientific papers and numerous books bear witness to his life's work, but his loss to the group at Bolton is immediate and will be difficult to bear over the coming months. It is fitting that 12 days before his death on 30 December 2013, his most recent paper co-authored with Professor Baljinder Kandola and Dr John Milnes was published 2 days before his death, and his last supervised PhD student was awarded her PhD 12 days before his death.
Dennis leaves a wife, Delphine, a daughter, Rebecca and two grandchildren Jake and Thomas. His son Vaughan died in 2005.
Written by Professor Richard Horrocks and Dr Brian Iddon, January 2014