Tannins
| The Biopolymer Network has developed new biopolymers derived from pine
bark for industrial applications. Specific pine bark tannin extracts and
modified tannins have been developed as bio-based functional additives
and formulated into industrial polymer products (e.g. plastics and
coatings). Input and support from industry partners is assisting in the
development of biopolymers for some commercial applications such as
speciality coatings. Furthermore, a comprehensive “whole-of-life” cost
model has been developed for the pine bark extraction process. This
model will provide a useful tool for assessing the commercial viability
of various manufacturing and investment scenarios.
|
|
 |
Pine Bark Tannin
Biopolymer Network pine bark tannin is a natural polyphenolic aqueous
extract obtained from the bark of Pinus radiata. It is ideal for a
wide range of applications where phenolic functionality or reactivity is
required along with antioxidant, antimicrobial and UV absorbing
properties.
|
Basic indicative properties
|
|
|
Physical form
|
A fine brown powder
|
|
Polyphenolic content (catechin equivalents)
|
> 65 %[1]
|
|
Carbohydrate content
|
< 20 %
|
|
Moisture
|
< 5 %
|
|
Molecular weight (weight average)
|
5000-7000
|
|
pH (5 % aqueous solution)
|
4.7
|
|
Bulk density
|
|
|
loose
|
0.2 g/ml
|
|
packed
|
0.4 g/ml
|
|
Solubility
|
|
|
Water, hot
|
Complete
|
|
Glycol
|
Complete
|
|
Ethanol
|
Partial
|
|
Acetone
|
Partial
|
|
Toluene
|
Insoluble
|
|
Weight loss on heating under nitrogen[2]
|
|
|
150 °C
|
0 %
|
|
200 °C
|
2 %
|
|
300 °C
|
17
|
[1] Higher contents and more refined grades are also available
[2] Gaugler and Grigsby (2009), Journal of Wood Chemistry and Technology, 29: p. 305-321
|
Functionality
|
|
|
Antioxidant activity (TEAC)
|
|
|
Pine bark tannin
|
5000-6000
|
|
For Comparison
|
|
|
Vitamin C[1]
|
3960
|
|
Antimicrobial activity (MIC)
|
|
|
Staphylococcus aureus
|
0.25 % (w/v)
|
|
UV/VIS absorption
|
|
|
λmax
|
270 nm
|
|
SPF (0.02% solution)
|
3
|
|
Antiprotease activity
|
|
|
Pepsin
|
Yes
|
|
Protex 6L
|
None exhibited
|
|
Trypsin
|
None exhibited
|
Applications
Pine bark tannin HW may find applications in a range of materials, for example as a:
•Phenolic substitute or co-reactant in adhesives and resins for plywood, particle board, MDF other wood or fibre products.
•UV stabiliser, antioxidant, heat stabiliser or corrosion inhibitor in polymer coating formulations.
•UV stabiliser, heat stabiliser, and antioxidant in polymer films and other plastic, foam or composite products or mouldings.
•Functional additive in personal care/cosmetics applications offering high potency antioxidant, antimicrobial and UV absorbing attributes.
•Precursor, co-reactant and multifunctional additive in a wide range of polymer and polymer foam products.
•Absorbent or complexing agent for selected molecules or elements.
Biopolymer Network Ltd has developed technologies to disperse and compatibilise tannin extracts in a wide range of polymer systems, including polyolefins as well as more polar polymers, to attain desired functional attributes. In addition novel derivatisation and co-reaction chemistries have been developed for many polymer and additive applications.
Availability
Test samples available on request.
Other purity specifications and refined extracts are also available on request – some with greater antioxidant functionalities than indicated above.
[1] Gliszczynska-Swiglo (2007), Food Chemistry, 101: p. 1480-1483