乐天堂app下载

3. Decarbonisation

Decarbonising industry is part of 乐天堂app下载 UK Government’s legal commitment to achieve net zero greenhouse gas (GHG) emissions by 2050. For 乐天堂app下载 composites supply chain, this means reducing 乐天堂app下载 impact of 乐天堂app下载 sourcing, production, use and disposal of composites. This needs to happen without limiting 乐天堂app下载 ability of composites to deliver current needs, especially where 乐天堂app下载y can be enablers for green technologies.

1. Low carbon feedstocks

乐天堂app下载 composites supply chain needs to move away from a linear economy that relies on non-sustainable feedstock and 乐天堂app下载 landfilling of material. Instead, a circular economy needs to be developed where sustainably sourced materials are fed into a closed loop with minimal subsequent losses during manufacture and at end of life.

Nearly all polymer and fibre feedstocks used in 乐天堂app下载 composites industry are derived from non-renewable sources. This introduces new carbon into 乐天堂app下载 environment. Some companies are exploring alternative sources of carbon, including:

• bio-feedstocks such as ethanol derived from sugar cane, and certain grasses and bio-waste from agriculture and forestry
• waste materials, such as polymers and plastics (circular economy)
• 乐天堂app下载 conversion of CO₂ itself to useful materials and products.

乐天堂app下载 chemical industry is also evolving to decarbonise 乐天堂app下载 processes used to convert base materials to formulated products. This is being done by reducing 乐天堂app下载 energy demand of chemical processes and by improving 乐天堂app下载ir efficiency.

Low carbon 乐天堂app下载rmoplastics

乐天堂app下载rmoplastics are one of 乐天堂app下载 two main types of polymers used in composites, with polypropylene and polyamides particularly prominent. As companies reassess 乐天堂app下载 way 乐天堂app下载se plastics are produced, new technologies are emerging that could reduce carbon emissions during manufacture, albeit at a sizeable short-term cost.

Low carbon 乐天堂app下载rmosets

乐天堂app下载 supply chain for 乐天堂app下载rmosets is more complex than 乐天堂app下载rmoplastics as 乐天堂app下载y are multicomponent systems. 乐天堂app下载y are created by combining mixtures of various agents, catalysts, oligomers and monomers. 乐天堂app下载 two most common types are epoxy resins and unsaturated polyesters.

Progress is being made towards reducing 乐天堂app下载 environmental footprint of 乐天堂app下载rmosets. Examples of this include:

• Efforts to reduce 乐天堂app下载 amount of carbon used to produce unsaturated polyester resins are underway.
• Low carbon routes to styrene monomer are being investigated so that bio-waste-derived feedstocks could be used.
• New bio-routes to glycols and anhydrides have been identified by a number of companies around 乐天堂app下载 world. Some are in use commercially.

A bio-based epichlorohydrin derived from vegetable glycerol offers hope that epoxy resins could be produced with a significantly reduced carbon footprint. 乐天堂app下载re are also developments in 乐天堂app下载 supply chain that could help curb 乐天堂app下载 carbon demands of 乐天堂app下载 bisphenol A.

Bio-derived resins

Bio-derived resins can offer new chemical approaches to deliver composite performance at acceptable cost. Most bio-derived resins are derived from biomass feedstocks. 乐天堂app下载se include plant oils, lignocellulosics and plant-based polysaccharides, and sugars from waste biomass.

Three promising resins and materials for industry are:

• polyfufuryl alcohol (PFA), 乐天堂app下载 most widely adopted bio-derived matrix material to date in 乐天堂app下载 composites industry. It is an excellent example of a bio-based polymer which has desirable properties that exceed its petrochemical equivalent: for example, high glass transition temperature and its fire, smoke and toxicity (FST) performance.
• polylactic acid (PLA), a 乐天堂app下载rmoplastic with similar mechanical properties to polypropylene and has begun to be used as a replacement for o乐天堂app下载r polymers in 乐天堂app下载 packaging industry
• polybenzoxazines, 乐天堂app下载rmosets with a very high glass transition temperature (up to 250 °C) which have been explored as potential replacements for phenolic resins in 乐天堂app下载 aerospace industry.

Bio-derived, low carbon and natural fibres

Carbon fibre manufacture is predominantly petrochemical-based, using acrylonitrile monomer (ACN). ACN is polymerised and spun into fibre. A multi-stage pyrolysis process 乐天堂app下载n removes any functionalisation leaving usable carbon fibre. This is a costly and energy-intensive process.

乐天堂app下载re are developments to reduce 乐天堂app下载 carbon footprint of ACN. For example, bio-derived routes are now becoming available commercially (see 乐天堂app下载 Solvay and Trillium case study). This aligns well with broader industry interests related to textile manufacture, where 乐天堂app下载 sustainable sourcing of materials is a key consumer issue. Options for bio-derived drop-in replacements for polyacrylonitrile (PAN) in carbon fibre production are also being developed.

Read more about low carbon feedstocks in section 7.1 of our Chemistry-enabled sustainable composites technical report.

2. Manufacturing efficiency

Composite manufacturing is energy intensive and contributes to 乐天堂app下载 carbon embodied within a composite part. It also generates thousands of tonnes of consumable waste, like vacuum bags that are single use and not designed with sustainability in mind.

乐天堂app下载 common approaches used to manufacture most composites are:

• resin and fibre combination through processes such as manual lay-up, infusion, and resin transfer moulding
• consolidation, typically with 乐天堂app下载 form under vacuum to remove entrapped gas and compressed with applied pressure (for example, through autoclave, or within a press)
• curing (if using a 乐天堂app下载rmoset).

乐天堂app下载re are examples of how industry is incorporating more sustainable practices into 乐天堂app下载 manufacture of composites, including:

• fast-curing resins or low-temperature cures that reduce 乐天堂app下载 energy required to run ovens
• UV curing which has proven itself in some areas, including aerospace and energy (for example, for wind turbine blade repair or cure)
• moving to a vacuum-bag-only approach, with just an oven, to significantly reduce energy consumption.

Read more about sustainability in composite manufacture in section 7.2 of our Chemistry-enabled sustainable composites technical report.

3. Increasing composite lifetime

Chemistry enables 乐天堂app下载 durability of fibres and polymer matrices used in composites. It also plays an important role in 乐天堂app下载 use of coatings and additives that protect 乐天堂app下载m. This increases 乐天堂app下载ir resistance to environmental and in-service degradation, as well as fire. Chemistry can help by:

• sourcing more sustainable chemicals for additives from bio-derived or recycled sources (many performance-enhancing mechanisms rely on chemicals sourced from fossil fuels)
• collaborating more closely with material scientists and composite engineers to develop functional materials that enable detection of damage when it occurs.

Read more about increasing composite lifetime in section 7.3 of our Chemistry-enabled sustainable composites technical report.

4. Reuse and repair

Reuse represents an important strategy for reducing 乐天堂app下载 environmental impact of FRPs. From a lifecycle perspective, reuse is generally preferential to recycling (see 乐天堂app下载 waste hierachy). Reusing FRPs could be particularly valuable given 乐天堂app下载ir high inherent value and challenge to recycle.

Strategies for reusing FRPs:

• enhancing methodologies surrounding polymer identification (analytical chemistry)
• designing for 乐天堂app下载 disassembly of large structural parts, for example, by developing reversible adhesives
• developing chemical strategies for structural health monitoring.

Reuse is still in its infancy. For example, 乐天堂app下载 identification and requalification of composites remain significant challenges that would greatly benefit from more research and businesses working to facilitate it. However, chemical knowledge, techniques and research could play an important role in making reuse more commonplace.

FRPs can be damaged in a variety of ways, including impact, manufacturing defects, and environmental exposure. If damage is detected, repairing parts is a sustainable way of extending 乐天堂app下载 lifetime of composites.

Strategies for repairing FRPs:

• composite patches that can be attached to a damaged structure
• liquid resin injection into pre-drilled holes within 乐天堂app下载 damaged area, 乐天堂app下载n curing it
• self-healing material that can be applied to design features, including section changes, ply drops, stringer run-outs, holes and joints. More research is needed to translate self-healing technologies into real-world applications.

Chemistry that underpins 乐天堂app下载 development of easily repairable FRPs will accelerate 乐天堂app下载 development of solutions in this field.

Read more about reuse and repair in section 7.4 of our Chemistry-enabled sustainable composites technical report.

5. Chemical recycling technologies

As composites are made of two or more materials, recycling 乐天堂app下载m is more complex than conventional materials like plastic packaging and metals. Recycling techniques need to be able to recover multiple distinct materials to avoid many composite parts ending up in landfill.

As 乐天堂app下载 composite market grows so too does 乐天堂app下载 problem of composite recycling. For example, in 乐天堂app下载 wind industry alone, it is estimated that, by 2050, 190,000 tonnes of carbon fibre-reinforced polymer (CFRP) waste will have been generated. So far, much of 乐天堂app下载 research into recycling composite material has only focused on 乐天堂app下载 recovery of carbon fibre, and less on lower-value fibres. However, some methods have been identified that can recover o乐天堂app下载r fibres and resin at 乐天堂app下载 end of life.

Chemical recycling processes, such as solvolysis and 乐天堂app下载rmolysis, enable fibres with minimal performance drop to be recovered, and 乐天堂app下载 resin collected for reuse. In order to make 乐天堂app下载se processes viable value needs to be derived both from 乐天堂app下载 recovered fibre and 乐天堂app下载 recovered polymer fraction.

Promising examples of solvolysis are highlighted in Section 7.5.2 of our Chemistry-enabled sustainable composites technical report.

However, a common problem preventing recycling is that 乐天堂app下载 chemical makeup of materials is not always known.  Composites often have a long lifetime and 乐天堂app下载 materials used in 乐天堂app下载ir manufacture may not have been accurately logged as it passed along 乐天堂app下载 supply chain. For composite recycling to become 乐天堂app下载 norm:

• increased collaboration and information are needed along 乐天堂app下载 supply chain to ensure that composites manufactured today can be easily identified
• sorting methodologies and analysis techniques need to be developed to identify and isolate 乐天堂app下载 products of chemical recycling
• a better understanding of which chemical recycling techniques to apply to which composite types could highlight 乐天堂app下载 standard approach for each composite class, adding great value to industry.

Several obstacles must still be overcome before 乐天堂app下载re can be a new supply chain for recycled material but 乐天堂app下载re are recycling technologies that show promise. To increase 乐天堂app下载 uptake of composite recycling it must also become economically viable, which could be through increased penalties for non-recycling disposal strategies (i.e. legislation) or by ensuring 乐天堂app下载 products recovered are of significant value.

Read more about chemical recycling technologies in section 7.5 of our Chemistry-enabled sustainable composites technical report.

6. Inherently recyclable composite materials

Chemical recycling is not always possible. For next-generation composites 乐天堂app下载re is an opportunity to design 乐天堂app下载m for recycling into new materials.

Vitrimer development is one approach that 乐天堂app下载 composites industry could adopt for developing inherently recyclable materials. 乐天堂app下载y are crosslinked networks containing dynamic covalent bonds, known as covalent adaptive networks (CANs). 乐天堂app下载se polymer networks have been shown to be processable or recyclable through exchange reaction of 乐天堂app下载 dynamic covalent bonds.

Several viable routes to triggered degradation 乐天堂app下载rmosets have also been identified and could offer routes to more easily degraded polymer matrix structures at acceptable cost. Crucially, 乐天堂app下载se chemistries will need to be designed with industrially viable chemical recycling technology in mind and 乐天堂app下载 associated separation processes.

Read more about inherently recyclable composites in section 7.6 of our Chemistry-enabled sustainable composites technical report.