Background

Current commercial plastics are lightweight inexpensive materials with excellent mechanical strength, toughness and flexibility, finding application almost in every field of application. However, most of the consumer plastics are fabricated from non-renewable fossil sources, are non-degradable and the impact of their use and disposal on the environment is extremely negative. Bioplastics derived from sustainable feedstock have been identified as a great alternative but they often lack necessary mechanical properties, are brittle and non-flexible.

Technology Overview

The new polymers developed at the University of Birmingham are based on isohexide isomers, which are derived from glucose (a widely available sugar), have excellent mechanical properties (from HDPE to Nylon-6), can be mechanically reprocessed (recycled) or even fully hydrolysed to recover the monomers for further refabrication of the polymers. The recycled polymers demonstrate no loss of mechanical properties.

Blending of different polymers (IIPU ‑ isoidide polyurethane ‑ with IMPU ‑ isomannide polyurethane) achieves a whole range of mechanical properties without compromising on degradability or processability.

Table 1. Thermomechanical properties

The stiffness and ductility of IIPU is comparable to commodity polyolefins, such as HDPE.

Figure 1. Stress-strain curve of IIPU, IMPU, HDPE and Nylon-6

IMPU displayed excellent recovery after deformation

Figure 2. IMPU - recovery after deformation

Figure 3. Predicted seawater degradation values

Benefits

Excellent adjustable mechanical properties
Excellent toughness (higher than Nylon-6 or HDPE)
Recyclable (can be recast at high temperatures)
Degradable by hydrolysis (monomers recovered and can be repolymerised into pristine polymer)
Degradable by seawater (equivalent to polycaprolactone or polylactic acid)
Recycled polymer retains mechanical properties
High thermal stability
Facile processing by heated compression moulding
Sustained optical clarity even at high strain (800%)

Applications

Automotive
Footwear
Consumer electronics casing
Packaging
Fuel tanks
Pipes
Frames and fittings
Gears and fixtures
3D-printing
Furniture
Toys and equipment
Cable insulators
Boats

Tough Reprocessable Thermoplastics from Biorenewable Sources (Sugars)

IP Status

Seeking