With STRUKTOL® POLYVERTEC® BioResins, Schill+Seilacher "Struktol" GmbH is striving towards its self-imposed goal of developing bio-based, environmentally friendly products in order to increase the environmental compatibility and sustainability of its product range. To this end, the development and production of unsaturated polyester resins (UP resins) based on renewable raw materials obtained by fermentation was started. The organic content of the pure, nearly odorless polyester resin is almost 100%. The product group is supplemented by bio-based tougheners for increasing the impact strength of thermoset matrix resins.

The polyester resin POLYVERTEC® 3830 is suitable for processing in all common UP resin processing methods and shows good mechanical properties:

  • Bio content close to 100% in pure polyester resin, odorless.
  • viscosity adjustable with common reactive dilutants or thickeners
  • no restriction in the choice of radical crosslinkers
  • compatible with common fillers and fibers
  • same mechanical properties as standard polyester resins
  • suitable for processes such as pultrusion or SMC/BMC

Together with our development partner manaomea GmbH, the first applications in the field of writing instruments and the furniture industry have already been brought to market maturity.

Unsaturated polyester resins (UPR) are reaction products of a dicarboxylic acid with a usually polyhydric alcohol. In this case the raw materials are 100% sustainable and renewable. Their respective production is based on biological processes (fermentation).

Bio-based UPR is used to replace classic styrene-based polyester resins. For a better processing the bio-based UPE can be mixed with diluents such as styrene or bio-based diluents. Typical applications are fiber composite systems and their products as well as their corresponding manufacturing processes, such as pultrusion and infusion. By thickening with MgO, SMC compounds and corresponding components can also be produced. It is compatible with both technical fibers (glass, carbon) and natural fibers (e.g. flax, jute, cellulose).

Struktol® Polyvertec® 3830

Bio-based (99%), high viscous polyester resin for mixing with reactive dilutant
application: hand lay-up, pultrusion and SMC processes

  • unsaturated polyester resin based on post-washing raw materials
  • Viscosity can be adjusted using reactive thinner (e.g. styrene)
  • well suited for the formulation of SMC moulding compounds
  • Acid number: 45 g/eq.
  • Dyn. viscosity (25 °C): 115 Pas (115,000 mPas)
  • Appearance: yellowish liquid

The elastomer modified epoxy resins are  rubber-free prepolymers that are created by the reaction of polymers with epoxy resins. The polymers used for this purpose primarily belong to the following groups: dimer fatty acids, polyols, polyurethanes, polyetheramines or thermoplastics.

These products, like CTBN-modified epoxy resins, improve technical characteristics such as impact strength, lap shear strength and adhesive strength. Depending on the modification, the handling of the rubber-free epoxy resins is easier, with an improvement in performance similar to the CTBN-modified epoxy resins.

Typical applications are adhesive formulations, coating systems, casting resins, prepregs and epoxy resin systems in the fiber composite industry.

Struktol® Polycavit® 3632

Dimer acid modified prepolymer (DGEBA)

  • Improving peel strength, flexibility
  • Epoxy-functional prepolymer of higher viscosity for the flexibilization of epoxy resin systems
  • especially suitable for use in coatings and cable sealing compounds
  • Dosage (replaces base resin): 10-40%
  • EEW: 600 g/Eq
  • Toughener content: 40 %.
  • Dyn. viscosity (50 °C): 47 Pa.s
  • Appearance: yellowish, highly viscous liquid
Struktol® Polycavit® 3637

Dimer acid modified prepolymer (DGEBA)

  • "Improving peel strength, flexibility
  • low viscosity version of Polycavit® 3632
  • especially suitable for use in coatings and cable sealing compounds"
  • Dosage (replaces base resin): 10-40%
  • EEW: 470 g/Eq
  • Toughener content: 30 %.
  • Dyn. viscosity (50 °C) : 8 Pa.s
  • Appearance: yellowish-transparent, highly viscous liquid