3 - Matrix materials

What’s the matrix in fibre-reinforced materials?

What are its purposes?

Material that surrounds & binds the fibres together

• applies forces to the fibres

• Reinforces bonding between fibres

• stabilises / holds the fibres in place

• Protects the fibres from environmental damage

Name different matrix materials

• unsaturated polyester resins (UP)

• epoxy resins

• Vinyl ester resins

• Thermoplastics

Properties of UP resins (unsaturated polyester)

→ Solution of UP dissolved in solvents which are incorporated into the polymer chains during curing (hardening)

→ 3-component system (polymerisation)

+ cheap

+ Flexible

+ Proven (avéré, efficace)

- shrinkage

- environmental issues du to styrene emissions

Properties of epoxy resins

→ 2-component system

+ low shrinkage

+ excellent adhesive properties

- expensive

- complex to use

Properties of vinyl ester resins (phenacrylate resins

• high toughness

→ flexible & resistant to cracking under stress

• high mechanical resistance

→ strong resistance to mechanical forces

• high-performance material

→ suitable for demanding applications

Particularity of thermoplastics as matrix in fibre-reinforced materials?

Name common thermoplastics used as matrices

→ can incorporate short, long, or continuous fibres to enhance mechanical properties

• polypropylene PP

• polyamide PA

• polyethylene ether ketone PEEK

Note: the other matrix materials like resins are thermosets (= duroplastics)