Strong ultralight foams based on nanocrystalline cellulose for high-performance insulation

Unmet Need: Energy efficient and renewable insulation materials.

Thermal insulation materials play a vital role in energy preservation in buildings and construction, transportation, and packaging industries. Expanded polystyrene has been widely used for commercial lightweight, high thermal conductivity insulation. However, it is petroleum-based, composed of toxic styrene blocks, and exhibits relatively poor fire resistance with substantial tail ash floating in the air after burning. It therefore poses the risk of environmental contamination and health side effects. In addition, polystyrene does not lend itself to easy degradation and adversely contributes to the landfill issue. Aerogels offer lower thermal conductivity; they are however too brittle for many applications. Therefore, there is an urgent need for renewable, greener, and cleaner alternative insulation materials to enhance environmental health and safety.

The Technology: Use of nanocrystalline cellulose for insulation foams.

A method to prepare high-performance composite foams based on plant fibrous materials in Nano and micro dimensions is presented. High-performance composite foams based on cellulose or its nanoparticles is fabricated. The formulation comprises of a mixture of cellulose with one or more crosslinking agent(s). The chemical interaction between the cellulose and crosslinking agent(s) through chemical bonds formation are responsible for the enhanced mechanical properties of foams having uniform cellular structure with smaller pore sizes.

Advantages:

Fabrication process uses only water as the solvent.
Foam has an excellent combination of thermal insulation capability, low density and mechanical properties.
The formulations result in strain values exceeding reported values of nanocellulose-based foams and a superior thermal conductivity.
Maintained structure with some shrinkage after foam burns into ash.
The composite foams exhibit elasticity and stress values similar to regular Styrofoam; and 100+ and 18 times higher values respectively than those of pure NCC foam.
Insulation tests show a 15% greater r-value over regular Styrofoam.

Applications:

High-performance thermal insulation materials contributing to energy savings, less usage of petroleum-based materials and reduction of environmental impacts.

Patent Information:

Provisional patent filed.