Fraunhofer-Institut für Silicatforschung ISC

Multifunctional coatings for a wide variety of materials

ORMOCER^® materials belong to the group of inorganic-organic hybrid materials and were developed at Fraunhofer ISC more than 30 years ago. They are constantly being optimized for many different applications and products, form a own class of materials and are manufactured using the sol-gel process. ORMOCER^® materials combine the advantages of inorganic (glass or ceramic-like) and organic (polymer-like) materials in a new, hybrid material.

This allows them to be used, for example, as very resilient but also extremely flexible protective coatings. The scientists at Fraunhofer ISC are thus in a position to offer customized synthesis, as well as functionalization and further processing of the ORMOCER^® materials according to customer-specific requirements.    

ORMOCER^® is not a classical composite material. The individual components are covalently and irreversibly linked to each other. The resulting parallel network formation of an organic and an inorganic network is responsible for the outstanding properties of the materials.

During synthesis (sol-gel process), an inorganic network is built by the targeted hydrolysis and condensation of organically modified silicon alkoxides. In addition, co-condensation with other metal alkoxides (Ti, Zr, Al alkoxides) is possible. Furthermore, the organic groups of the silicon alkoxides can contribute to an organic functionalization of the inorganic network and thus bring additional functions to the material.

ORMOCER^®: a coating with many advantages

Hybrid polymer coatings possess a wide range of outstanding properties that not only enable but also simplify their implementation on an industrial scale.

In addition to numerous possible combinations of the individual functions, it is relatively easy to apply ORMOCER^® coatings using conventional application methods and to cure the coatings at low temperatures.

Due to the use of non-critical reactants (no critical solvents are used) and the low temperature during curing, ORMOCER^® surface coatings can make their contribution to the careful use of resources and thus to sustainable materials management.

ORMOCER® coatings

The way to new compostable packaging materials

In further developing the classic ORMOCER^® to bioORMOCER^® materials, we took our cue from nature. Horsetails and diatoms build their scaffold structures from bioorganic and silicate building blocks and thus serve as models for the synthesis of bioORMOCER^® formulations. In analogous way, we incorporate biomolecules into the network of the classic ORMOCER^® matrix. These can be of plant origin (e.g. cellulose-based), but can also be of animal origin, such as chitosan.

The special feature of incorporating the biomolecules is that they are not just incorporated as an additive, but are covalently bonded to the matrix. This guarantees that the properties of the ORMOCER^® materials are maintained or even improved.

The bioORMOCER® layers obtained are not only partially biobased, but are also biodegradable. The incorporated biomolecules can be seen as predetermined breaking points through which the network is more easily and quickly attacked.

Since the focus of the application is in the field of packaging, compost tests were also carried out. According to industrial conditions (ISO 14855-1:2013), the degradation of applied layers and also of individually analyzed layers could be confirmed.

Biodegradation is interesting for many applications, e.g. also in the medical environment. However, biobased molecules are often not suitable for this purpose in terms of quality and purity. For this reason, bioORMOCER^® formulations can also be produced that contain polycaprolactone-triol (PCL-T) as a biodegradable component. Although this is fossil-based, it can nevertheless be covalently linked to the ORMOCER^® matrix and is also biodegradable in a similar way to celluloses, for example.