Processing and Upscaling of Fire-Resistant Nano-Filled Thermosetting Polyester Resin

The Polyfire ProjectProject Aims:

• Develop and scale-up fire-retardant polyester-nanoclay resin systems and processing techniques• Eliminate halogenated fire-retardant additives• Reduce weight and cost• Improve safety in a number of fire-critical sectors including construction and marine

Key Facts:

• A collaborative European project, funded by the European Commission 7th Framework Programme.

•11 partners from 5 countries (5 SMEs, 3 research institutes, 2 large companies, 1 association)•3 years (1 September 2009 – 31 August 2012)

The Challenges

• To achieve good fire performance, the clay must be correctly dispersed in the resin

• Evidence suggests that an intercalated structure is preferable for fire-retardant properties, because these ideally require the clay platelets to be in parallel to create a consistent barrier

• Organomodification of the clay surface is required in order to increase platelet-platelet separation and increase compatibility with the UP resin

• Polymer molecules can then enter the clay gallery and start to overcome the inter-layer attractive forces

• Mechanical mixing is then needed, to provide the required level of dispersion

• The Polyfire project will develop and optimiseboth the organomodification and mixing processes.

• Both processes will be scaled-up to demonstrate industrial production feasibility.

• A comprehensive health and safety evaluationwill be carried out, taking into account the entire life-cycle of the materials.

This project has received funding from the European Community's Seventh Framework Programme FP7/2007-2013 under grant agreement n° 229220.

www.polyfireproject.eu

Industrial Interest GroupOrganisations interested in the Polyfire project are invited to join our Industrial Interest Group:

• Exchange the scientific and technological information necessary for the successful direction of the project and the achievement of its objectives

• Cooperate with industrial researchers and technologists regarding the innovative concepts developed

• Keep informed on the progress of the Polyfire project

For More Information

Case Studies• At least three demonstration composite panels will be produced and tested to showcase the

materials and process developed in the Polyfire project.

• The parts selected to date are a passenger ferry balcony floor, a train interior panel and a passenger lift wall panel.

Balcony of Passenger Ferry Train Interior Panel Passenger Lift Wall Panel

BackgroundUnsaturated Polyester Resins

• Extensive use in fibre-reinforced composites and coatings

• Low cost, good processability and balance of properties

• But, burn vigorously and generate dense smoke

• Fire performance improved by using fire-retardant additives

Fire Retardant Additives

• Halogenated compounds, antimony-based systems and non-combustible fillers (such as aluminium trihydrate, ATH) are the most common

• Halogentated systems can generate large quantities of toxic and corrosive combustion products, so tend to perform poorly in more modern fire tests

• The growing trend is towards halogen-free additives, such as ATH or ammonium polyphosphate (APP)

• But these must be used at high loading to achieve the desired fire performance

• Processability, strength and impact resistance are all reduced and weight is increased

Clay as a Fire Retardant

• Addition of small amounts of well-dispersed, nano-sized particles can result in simultaneous improvement in a range of mechanical and physical properties, including fire retardancy

• The improvement in fire retardancy is attributed to the formation of a continuous, defect-free char

• The char forms a barrier on the surface, protecting the un-burnt polymer beneath

• Synergistic interactions between nano-dispersed clay, resin and traditional fire-retardant additives have been identified

• Previous studies have produced a halogen-free, nanoclay ‘filled’ unsaturated polyester resin (UP NC) which passed UL94-V0

• Cone calorimeter tests showed similar performance to BS476 pt7 class 2 halogenated system

• Achieved equivalent performance to halogenated UP resin with 20-25% cost reductionComparison of Heat Release Rate for clay-filled

unsaturated polyester (UP NC) and unfilled unsaturated polyester (UP).

FEG-ESEM showing the clay/carbon char layer on the surface of Nylon 6,6 polymer.

Char Layer

Polymer

Dr Ben HargreavesNetComposites Ltd4A Broom Business Park, Bridge WayChesterfieldS41 9QG, UK

Phone: +44(0)1246 266244Fax: +44(0)1246 266249

email: info@netcomposites.comWeb: www.polyfireproject.eu

Polymer

“Traditional” phase-separated microcomposite

Ordered intercalated

nanocompositeDisordered exfoliated

nanocomposite

Cationic Surfactant

Clay Layer