Periodic Reporting for period 3 - SSUCHY (Sustainable structural and multifunctional biocomposites from hybrid natural fibres and bio-based polymers)
Reporting period: 2020-09-01 to 2022-02-28
Interest in composites from renewable and sustainable resources is expanding rapidly. Even if research and innovation in plant fibre composites (PFCs) is growing fast, in particular in well-established application sectors (such as automotive and plastic industries, building and construction), the development of structural PFCs is still a result expected but not yet fully achieved. The penetration of PFCs in the market of structural composite is low. Until now, most of the effort has been devoted to the development of short-fibre and non-woven based composites, which are not suitable for structural applications. The main challenges are related to the development of sustainable methods to expand purpose-grown biomass, service-life and long-term durability, design and engineering of bio-based materials that can exhibit tolerance against various external factors. Beyond this, there is also a strong need to develop all-green composites with a good durability and cost efficiency.
In such a context, SSUCHY aimed at exploiting the intrinsic and differentiating properties of plant fibres (in particular, hemp) and biopolymers derived from lignocellulosic feedstock to develop fully bio-based composites with high structural properties and advanced functionalities. The main driver behind this project is not only to substitute conventional fossil-based materials with more sustainable bio-based ones but also to achieve improved functionalities that surpasses those of fossil-based ones. Enhanced functionalities are, in addition to load-bearing resistance and weight reduction of structures, enhanced durability, vibration damping, vibro-acoustic control and fire retardancy. Such developments would provide to the composite industry a significant value and functions added products with high socio-economic impacts and minimized environmental impact. It will create opportunities to expand market applications for bio-based composites to semi-structural and functional applications in transportation along with new opportunities in high added value niches. In addition to the use of renewable constituents, this project also proposes to measure and minimize the environmental impact and energy consumption of the processes. A complete Life Cycle Analysis of the developed products is provided. The proposed methodology was implemented within the framework of a multi-level eco-efficiency approach which covers experimental aspects, as well as process optimization, modelling and design. It comprises three main research axis:
(i) development and optimization of a competitive hemp fibre reinforcements for composite applications,
(ii) development and optimization of two fully bio-based polymers with advanced functionalities, a thermoplastic aliphatic polyester and a thermoset epoxy mainly synthetized from lignin-derived building blocks,
(iii) implementation of advanced functionalities in plant-based materials and structures to prove the concept at the scale of demonstrators.
In such a context, SSUCHY aimed at exploiting the intrinsic and differentiating properties of plant fibres (in particular, hemp) and biopolymers derived from lignocellulosic feedstock to develop fully bio-based composites with high structural properties and advanced functionalities. The main driver behind this project is not only to substitute conventional fossil-based materials with more sustainable bio-based ones but also to achieve improved functionalities that surpasses those of fossil-based ones. Enhanced functionalities are, in addition to load-bearing resistance and weight reduction of structures, enhanced durability, vibration damping, vibro-acoustic control and fire retardancy. Such developments would provide to the composite industry a significant value and functions added products with high socio-economic impacts and minimized environmental impact. It will create opportunities to expand market applications for bio-based composites to semi-structural and functional applications in transportation along with new opportunities in high added value niches. In addition to the use of renewable constituents, this project also proposes to measure and minimize the environmental impact and energy consumption of the processes. A complete Life Cycle Analysis of the developed products is provided. The proposed methodology was implemented within the framework of a multi-level eco-efficiency approach which covers experimental aspects, as well as process optimization, modelling and design. It comprises three main research axis:
(i) development and optimization of a competitive hemp fibre reinforcements for composite applications,
(ii) development and optimization of two fully bio-based polymers with advanced functionalities, a thermoplastic aliphatic polyester and a thermoset epoxy mainly synthetized from lignin-derived building blocks,
(iii) implementation of advanced functionalities in plant-based materials and structures to prove the concept at the scale of demonstrators.
The main outputs at the end of the SSUCHY project are the followings:
Innovative hemp value chain for composite reinforcements:
The objective of this work was to produce hemp-based reinforcements for composite applications by proposing and optimizing suitable primary (from stems to rovings) and secondary (fabric manufacturing) processing routes. In Europe, hemp is currently processed using mechanical systems such as hammer mills, also known as decorticators, which provide fibres in the form of short and medium-length fibres from disordered straws. This processing method is quite damaging for the fibres and the mean values of their resulting tensile properties are generally lower than for flax. In the SSUCHY project, we investigated two alternative routes. The first one uses the flax value chains for long line fibres and tows from aligned straws and the second one consists in decorticating randomly aligned straws out of the traditional textile flax production zone. In both cases, the goal was to produce continuous aligned reinforcements fabrics from selected hemp varieties, namely Futura 75 and Fibror 79, cultivated and processed in Italy and France, using optimized agronomic, retting and processing conditions.
Fully bio-based composites:
A wide range of bio-based composite and sandwich materials were studied during the SSUCHY project to evaluate their processability and performance level. Fully bio-based composites were produced from the woven hemp fabrics and the bio-based epoxy thermosets (BioIgenox and Bisguaïacol-based epoxy). The obtained composites reach the target in terms of thermomechanical properties, with a Tg higher than 100°C, bending properties comparable and even sometimes surpassing those of DGEBA-based epoxy composites and with a toxicity and environmental impact lower than for the traditional glass fibre reinforced DGEBA-based epoxy composites. This is one of the main achievements of the SSUCHY project and it did establish an interconnection between the wood-derived building blocks and hemp value chains. As a result, a new, innovative and economically-viable value chain is proposed for the development of structural and fully bio-based composites from plant biomass.
Product demonstrators and prototypes:
Four product demonstrators were developed during the SSUCHY project using the hemp reinforcements:
- floor and trim panel structures for cars,
- a monocoque structure for electric scooters,
- a cockpit panel for electric aircraft,
- a high-end green loudspeaker system.
For most of them, results demonstrated the superiority of the proposed bio-based solutions (when compared to the petroleum-based solutions) in terms of stiffness to weight ratio. Results also confirmed the high potential of plant fibres to increase the damping of composite materials when compared to their petroleum-based counterparts and then tune the vibro-acoustic response of structures.
Life Cycle Assessment
The environmental performance of the entire life cycle of the bio-based product demonstrators was assessed during the project and compared to the benchmark solutions. The assessment was conducted in accordance with ISO standards on LCA and the International Reference Life Cycle Data System (ILCD) Handbook. The LCA results demonstrated that all demonstrators have lower environmental impacts than their petroleum-based conventional counterparts available in the current markets, especially in terms of the reduction in Global Warming Potential (GWP).
Innovative hemp value chain for composite reinforcements:
The objective of this work was to produce hemp-based reinforcements for composite applications by proposing and optimizing suitable primary (from stems to rovings) and secondary (fabric manufacturing) processing routes. In Europe, hemp is currently processed using mechanical systems such as hammer mills, also known as decorticators, which provide fibres in the form of short and medium-length fibres from disordered straws. This processing method is quite damaging for the fibres and the mean values of their resulting tensile properties are generally lower than for flax. In the SSUCHY project, we investigated two alternative routes. The first one uses the flax value chains for long line fibres and tows from aligned straws and the second one consists in decorticating randomly aligned straws out of the traditional textile flax production zone. In both cases, the goal was to produce continuous aligned reinforcements fabrics from selected hemp varieties, namely Futura 75 and Fibror 79, cultivated and processed in Italy and France, using optimized agronomic, retting and processing conditions.
Fully bio-based composites:
A wide range of bio-based composite and sandwich materials were studied during the SSUCHY project to evaluate their processability and performance level. Fully bio-based composites were produced from the woven hemp fabrics and the bio-based epoxy thermosets (BioIgenox and Bisguaïacol-based epoxy). The obtained composites reach the target in terms of thermomechanical properties, with a Tg higher than 100°C, bending properties comparable and even sometimes surpassing those of DGEBA-based epoxy composites and with a toxicity and environmental impact lower than for the traditional glass fibre reinforced DGEBA-based epoxy composites. This is one of the main achievements of the SSUCHY project and it did establish an interconnection between the wood-derived building blocks and hemp value chains. As a result, a new, innovative and economically-viable value chain is proposed for the development of structural and fully bio-based composites from plant biomass.
Product demonstrators and prototypes:
Four product demonstrators were developed during the SSUCHY project using the hemp reinforcements:
- floor and trim panel structures for cars,
- a monocoque structure for electric scooters,
- a cockpit panel for electric aircraft,
- a high-end green loudspeaker system.
For most of them, results demonstrated the superiority of the proposed bio-based solutions (when compared to the petroleum-based solutions) in terms of stiffness to weight ratio. Results also confirmed the high potential of plant fibres to increase the damping of composite materials when compared to their petroleum-based counterparts and then tune the vibro-acoustic response of structures.
Life Cycle Assessment
The environmental performance of the entire life cycle of the bio-based product demonstrators was assessed during the project and compared to the benchmark solutions. The assessment was conducted in accordance with ISO standards on LCA and the International Reference Life Cycle Data System (ILCD) Handbook. The LCA results demonstrated that all demonstrators have lower environmental impacts than their petroleum-based conventional counterparts available in the current markets, especially in terms of the reduction in Global Warming Potential (GWP).
Within the SSUCHY project, new bio-based constituents for composite applications (hemp fibre reinforcements and fully bio-based polymers), new bio-based composite materials and structures were successfully developed. Their advanced functionalities were demonstrated at the scale of product demonstrators. Through these developments, SSUCHY aims at increasing the sustainability and the competitiveness of Europe’s industry through engagement in the bio-based composite sector. SSUCHY also directly contributes to the Sustainable Developments Goals 12 and 13. A sustainable management and efficient use of natural resources such as hemp and wood and their by-products is proposed in the project. For the hemp processing, a technology readiness level of 6-7 is reached. The proposed materials and products, when launched on the market, will contribute to the decrease of CO2 emission by substituting petroleum-based materials by low-weight bio-based composites and products.