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Synergic combination of high performance flame retardant based on nano-layered hybrid particles as real alternative to halogen based flame retardant additives

Final Report Summary - PHOENIX (Synergic combination of high performance flame retardant based on nano-layered hybrid particles as real alternative to halogen based flame retardant additives)

Executive Summary:
PHOENIX consortium was created in order to find a solution to substitute the halogenated flame retardant (HFR) additives employed in the fabrication of flame retardant (FR) thermoplastic and thermoset materials, used in a wide range of commercial products, applications and markets, such as electrical/electronic devices (E&E), low-voltage wires or household appliances. HFR have revealed to be dangerous to health and environment, and their use and recyclability is explicitly addressed by several EU directives such as WEEE and RoHS.
Non-halogenated flame-retardants alternatives are commercially available, but due to the high filler content (>30% or even >60%) needed to provide the same FR properties than traditional HFR (filler content >15%), the processability and final product properties are significantly reduced whilst the cost of the parts is considerably increased, severely limiting the range of applications and hindering non-Halogenated FR market introduction to replace dangerous HFR.
PHOENIX project was an ambitious multidisciplinary innovative threefold approach to develop:
(i) A new concept of FR nanostructured materials, based on new non-halogenated flame-retardants applying nanotechnology to replace hazardous chemicals to produce sustainable FR additives based on nanolayered structures produced using innovative green chemical routes and modified lignins, produced with innovative and green chemical routes, for thermoplastic and thermoset applications.
(ii) Innovative processing routes, providing solutions to the demands of the EU Industry regarding FR, finding a true cost-effective and sustainable alternative to existing non-environmentally friendly HFR, which allows simultaneously a significant improvement of mechanical properties and processability, highly limited with the existing non-halogenated FR available in the market for compounding, extrusion and injection moulding processes. New compounding techniques such as Nanodirekt process, and high innovative systems, such as ultrasounds mixing systems coupled to extrusion and injection equipments, will assure high nanoparticles dispersion in the polymer nanocomposites and in the final pieces, thus achieving optimal properties.
(iii) Simulation and modelling of compounding processes for producing optimal nanocomposites, avoiding aggregates and achieving the best dispersion of the nanoparticles in the polymer matrix.

Project Context and Objectives:
The most conventional fire retardants are halogen-based compounds, due to the low price and the capability to enhance fire-retardancy of polymers without degrading their physical properties, such as impact strength. They have the 30% w/w of the current FR market. However, toxic species such as dioxins and furans , which are generated during the combustion of halogen-containing composites, could cause serious environmental contamination.
Therefore, developing halogen-free, low-smoke generating, and environmentally-friendly fire retardant composites has become increasingly important in recent years, based on a diverse range of chemicals classified as: 1) Inorganic hydroxides, such as Al(OH)3 and Mg(OH)2, representing 57% w/w of the market, 2) Phosphorus based organic and inorganic phosphates and phosphonates (8% w/w of the market), 3) Nitrogen based: typically melamine derivatives (3% w/w of the market).
In the industry, a combination of them are also employed. However, high levels of loading (30-60 wt%) are required, leading to additional costs, processing difficulties and a decrease in physical properties of polymers. Hence the development of new highly effective, “green” fire retardants has prompted much attention during the last decade.
PHOENIX flame-retardants were produced via a water-based sustainable production method exploiting the capacity to form, by self-assembly technology, “nanoplatellets structures” by a synergic combination of different types of nano-layered nanoparticles, hollow nanoparticles (containing organic phosphonates or melamine phosphate) and modified lignins with different fire retardant mechanism.
To minimize the amount of required FR and to enhance the dispersion of the nanoparticles in the thermoplastic resins, different technologies were investigated and optimized such as Nanodirekt compounding, ultrasound and static mixers in the injection unit and multilayer co-extrusion and co-injection. Moreover, the incorporation of developed FR was also incorporated in epoxy resins, in order to study the compatibilization and content needs for this kind of thermoset materials.
The main industrial sector in which PHOENIX developments will have major impact is the Electrical and electronic (E&E) sector, including housings, wire and cable, and internal parts such as connectors. The E&E is the largest market for flame retardants (FR) in plastics globally; the total EU plastics demand being estimated around 2.6 million tons in 2010. This demand is expected to grow, as the need for FR is increasing due to electronics miniaturization and higher usage temperatures. As E&E parts become smaller and thinner, FRs must withstand higher processing temperatures without compromising the thermoplastic material's flow and mechanical properties. As described in the Impact section, PHOENIX developments on low-voltage electric wires and injected and extruded thermoplastic parts will have impact not only to the E&E sector, but also to all other industrial sectors making use of them, such as household appliances, automotive, computers, white goods, construction, among others.
PHOENIX main objectives to fulfil the requested fire safety standards were:
1) Producing sustainable flame retardant nanoparticles that can be acceptable in terms of industrial hygiene, consumer safety, and environmental impact. The solvents employed were mainly based in water and the products involved are inorganic salts from natural sources. The synthesis was based in pH changes and the use of templates to model the size and shape of the nanoparticles. The templates employed were non-toxic and natural organic compounds such as lauryl sulphate or urea. Nanoparticles fulfil the safety and health test according the current state of the technique.
2) Nanotechnology approach. Self-assembly molecules (SAM) technology was used to functionalize nano-layered FR particles and form ordered nanostructures, as a new approach to develop functional nanocomposites with enhanced FR properties.
3) New FR additives from renewable source based on modified lignins with synergic effect with proposed nano-layered FR particles. Lignin were modified to incorporate non-polar groups (to improve polyolefin compatibility) and various phosphorous- and boron-containing reagents to increase their fire retardancy capacity. Base lignin was a by-product of the paper industry.
4) Reduction of FR content. A maximum 15% w/w FR content compounds produced thanks to the use of different types of nano-layered particles and organic phosphonate placed in ordered structures. The synergy is achieved by a combination of silica encapsulated phosphonates with different fire-action nanoparticles (metallic hydroxides and graphenes). This reduction of FR needs will be also achieved by innovative processing technologies (objectives 5, 6 and 10).
5) NanoDirekt Process contributes to improve nano-layered flame retardant dispersion without aggregation because water removing is not required for twin screw extruder feeding. This new technology contributes to a cost reduction compounding process and a reduction of the necessary amount of FR additives to fulfil the proposed requirements.
6) New module for Ludovic software was specifically developed to simulate nanofilled FR thermoplastic compounds.
7) Good processability in conventional plastic production equipment, thanks to the particular characteristics of the self-assembled nanoparticles that will provide a suitable matrix-nanoparticle interaction and the capacity to improve the nanoparticles dispersion of standard machines by using ultrasound devices and static mixers.
8) Competitive cost, less than 20% cost increase regarding current HFR compounds and cost competitive in comparison with currently available non-halogenated FR, but improving the final properties
9) Processing routes using multilayer co-extrusion (in wire and thermoformed parts) and co-injected (housing parts) structures, to create a protective layer by maximizing the amount of the FR additives in the skin layer and reducing the percentage in core, depending on the application, without reduction of FR and mechanical performance of the final part.
10) Development of a stable epoxy pre-pregs containing FR nanoparticles that fulfil the fire requirements in the electric-electronic industry (mainly household appliances). Commercial fireproof halogen free formulations of epoxy resins are based on ammonium polyphosphate, organo phosphorous and Aluminium hydroxide.
11) Increase mechanical and thermal properties in comparison with HFR by at least 10% for the selected materials.
12) Fully recyclable compounds, up to a 30% of recycled materials will be added to the virgin material without significant loss of mechanical properties (less than 10%).
13) Methodology development and standardization of quick or in-line test to evaluate the fire resistance of develop compounds.
14) Positive environmental impacts (by a LCA preparation in accordance with the ILCD handbook), in comparison with non-halogenated flame retardants formulations.
15) Technical, performance, health, environmental and economic factors must be duly considered in the justification of the choice of the optimum novel flame retardant material for the selected applications.
Assessment of PHOENIX objectives at the end of the project:
Objective Achieved? Any deviation? Partners involved
Definition of the needs and requirements of the end users of flame retardants and nanocomposites to be developed. YES / NO / ALL
Producing sustainable flame retardant nanoparticles and functionalization (SAM technology) / Partially / Partial desviation *GR1 best candidate *Problems with encapsulated FR for high temperature thermoplastics *Nanohydroxides low thermal stability for thermoplastics *Very good performance for thermoset materials / AIT / AIMPLAS / ENSCL
New FR additives from renewable source based on modified lignins / Partially / Partial desviation / • Good performance at lab scale • Optimization needed for industrial scale-up /FhG-LBF ENSCL
Reduction of FR content → MAX. 15% / Partially / Partial desviation: • Good dispersión for nanomagnesium hydroxide • Not suitable for GR1 suspension at industrial scale (good at pilot plant scale) / FhG-ICT, Bada
Develop new module of LUDOVIC software to simulate nanofilled FR thermoplastic compounds / YES / NO /AIMPLAS, SCC, ALFA
Improvement of dispersion using US device / Partially / Partial desviation: • All tested nanoparticles showed good dispersion without US • New trials with nanoclays to evaluate the influence / FhG-ICT, A&E
Co-extrusion and co-injection of FR/ YES / NO / FhG-ICT, A&E, AIMPLAS, ENSCL
Development of a stable epoxy pre-pregs containing FR nanoparticles / YES / NO / AIT, AIMPLAS, VonRoll
Fully recyclable compounds / YES / NO / Akumplast, Polyraz
Translate the knowledge to industrial scale To demonstrate the potential of the FR nanocomposites / YES / NO / Arcelik, Artic, Revi, Polyrax, Akumplast
Competitive cost, less than 20% cost increase regarding current HFR compounds / Partially / Achieved for PP and HDPE compounds based on PH1 but not for the rest of formulations / Arcelik, AIT, Revi
Positive environmental impacts (by a LCA preparation in accordance with the ILCD handbook), in comparison with non-halogenated flame retardants formulations / YES / NO /TUD
To demonstrate that PHOENIX developments comply with Health, Safety and Regulatory requirements / YES / NO / AIMPLAS, FhG-ITEM
Technology Transfer, Exploitation and Dissemination of knowledge generated in the project. Contribution to standards / YES / Partially achieved: standarization was not possible / ALL

Project Results:
Main results up to date Main Partners involved Support partners
1.- Good results in thermoset composites.- V0 with 3,1% of filler in 3,5 mm VonRoll (Main partner) AIT (support)
2.- Good fire behavior using graphene as synergist for thermoplastic compounds / Main partners: REVI, ARCELIK, ARCTIC, POLYRAZ, AKUMPLAST Support:ENSCL, BADA, ALFA, AIMPLAS, FhG-ICT
3.- Using FR material at the skin of the co-injection and co-extrusion processes; this results with FR behavior; Main partner; AIMPLAS, FhG-ICT ; support: ENSCL
4.- Good FR behavior in ABS and phosphorylated lignin at lab scale ; Main: ENSCL, FhG-LBF ; Support: AIMPLAS
5.- Optimized US equipment, Main partner: FhG-ICT,A&E; support: AIMPLAS
6.- PP and HDPE HFFR formulations very good performance and competitive price - Main partners: ALFA, AIMPLAS, POLYRAZ, REVI, ARTIC, AKUMPLAST, ARCELIK, FhG-ICT
7.- HIPS HFFR formulations very good performance but the price is not competitive - Main partners: BADA,ENSCL, ARCELIK, FhG-ICT, ARTIC

Tables including main achievements in each WP are included as attachment

Potential Impact:
The PHOENIX workplan was focused on providing solutions to the real needs of the Industry regarding flame retardants (FR): finding a true alternative to existing halogenated FR which allows simultaneously a significant improvement of mechanical properties, currently hindered with the existing non-halogenated flame retardants available in the market.
A strong interaction between the whole SMEs partnership/industries and research organisations ensured the complementary fields involvement along the project implementation. The participation of end-users guaranteed high impact and the wide dissemination & exploitation of the project results at National and EU level. The achievement of the results represented a significant advantage to the SME and End User participants demanding halogen-free FR materials to manufacture high-performance parts.
The impact of PHOENIX project affects nanoparticles producers (synthesis and functionalization), compounders, thermosetting parts manufacturers, sheet extrusion, thermoforming, software & machine manufacturers and injection moulders.
The expected impacts regarding to different segments of the value chain directly represented in the project are:
- Nanoparticles producers (AIT): Production of graphene as FR synergist for thermoplastic compounds, technology that can be adapted to new markets in order to optimize their adhesion to different plastic matrices. Production of PH1 mod encapsulated particles for thermoset resins and low temperature thermoplastic polymers (HDPE)
- Compounders and thermoset formulations (ALFA, BADA, VONROLL): Production of graphene as FR synergist for thermoset and thermoplastic composites. Use of PH1mod for thermoset resins and low temperature thermoplastic polymers (HDPE)

- Plastic processors (AKUMPLAST, POLYRAZ, REVI): will develop an optimized process to produce more innovative and environmentally friendly products with better properties production of FR synergist for thermoplastic compounds and competitive price. Reduced costs, sustainable products and an increased and differentiated portfolio will result in a higher turnover. Using FR material at the skin of the co-injection and co-extrusion processes; this results with
- Compounding simulation Software: LUDOVIC manufactured by SCC is adapted to new FR materials
- End users (ARCTIC, ARCELIK, REVI, AKUMPLAST, POLYRAZ): will be able to differentiate from competitors by introducing a new line of products employing sustainable FR plastics with better properties. They will improve their environmentally-friendly image by using the new materials containing lignin from biowaste, helping them to increase their business.
- Academic and Research centers (ENSCL, FhG-LBF, TUD): further research is also available with the promising results of the FR behavior in ABS and ,phosphorylated lignin at lab scale.
The sector addressed in PHOENIX project was E&E appliances. As collected in the tables from below, PP and HDPE formulations and compounding studies showed Phoenix compounds give promising results and have potential to replace current commercial products in terms of cost. However, total HIPS material cost is higher than current material.

Total Prices of Phoenix Materials
Compounds Total Price of Phoenix compounds (€/mt) Prices of Current Material (€/mt)
PP- PH1 %15 / 2200 / 2500-3000
PP- PH1 %18 2272 / 2500-3000
PP-APPÇ / 3109 / 2500-3000
HIPS PPO 5435 / 1800-2500
HDPE PH1 2124 / 1600-2500

Table 15. Comparison of Component Price
Compounds Total Price of Component (€/mt) / Price of Custom Material (€/mt)
PP- PH1 %15 / 2200-2250 / 2500-3000
PP- PH1 %18 / 2272-2302 / 2500-3000
PP-APP 3109-3159 /2500-3000
HIPS PPO 5435-5700 /1800-2500
HDPE PH1 2124-2200 / 1600-2500

The developed PHOENIX materials may be suitable for other application sectors. Optimum flame retardant properties have been achieved for HDPE, PP and HIPS compounds. HDPE and PP based formulas resulted in a very competitive price and the content of flame retardant additive is very low compared to commercial ATH and HOM halogen free formulations. HIPS compounds price was less competitive but it could find other markets and applications with less price restrictions. It has to be pointed out that the final product can be produced by co-injection and co-extrusion which means that the final content of the HFFR compounds will be reduced. Therefore, the final costs could be decreased by creating multilayer structures.
Taking this facts into account, PHOENIX partners have identified the following applications in which the developed compounds could be competitive:
1. Transport
2. Building and construction
3. Upholstered Furniture and Textiles
4. Electrical and Electronic Devices

List of Websites:
Project Coordinator: AIMPLAS
C/ Gustave Eiffel, 4
València Parc Tecnològic
46980 Paterna (Valencia)
Tel: +34 961 366 040 Ext. 150
Fax: +34 961 366 041