Alexis Chopin, Eurostar Engineering Plastics, presented radiation-activated cross-linking processes which can improve polymer heat stability and fire performance. In addition to reducing polymer decomposition and improving heat resistance, cross-linking modifies char characteristics. A combination of cross-linking and PIN organo-phoshorous flame retardant in polyamide enabled to achieve UL94-V0 (0.4mm) and EU railway EN 45545 smoke emission R23 HL3. Eurostar now offer PIN-FR radiation crosslinkable polyamide both with and without glass fibre reinforcement.
Severine Bellayer, UMET/ISP Lille, presented tests of sol-gel application to polyurethane foams of phosphorus and silicon based flame retardants (DEP, APTES, TEOS), showing a 1/3 heat release rate reduction. Bio-sourced molecules (adenosine triphosphate, chitosan, cysteine) were tested as replacements for DEP, but showed to be less effective.
Andy Goodwin, First Graphene Ltd., Perth, Australia, presented the company’s large platelet graphene product (20-40 µm), mined in Sri Lanka and processed by exfoliation. This graphene has been tested, in combination with inorganic PIN flame retardants, as a fire protection surface treatment for e.g. paper and wood. It functions by generating an intumescent char layer, acting as an oxygen barrier and also limiting toxic gas release in fire.
Bansi Kaul, MCA Technologies, presented the company’s triazine products (see previous pinfa Newsletters: 61, 72, 76, 80). He considers that these can act in synergy with various PIN FRs including metal hydroxides, calcium carbonate, kaolin and organo-phosphorus FRs.
Hans-W. Marx, Linseis Messgeräte, presented different methods and equipment for thermal conductivity measurement in fire testing, underlining the need to take into account that thermal conductivity changes in samples with temperature and with polymer decomposition.