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Triggered Polymerization Resin Blends

Resins, Oligomers, Monomers

Catalysts Systems

In this section we will list a number of catalyst that will trigger it's desired action through an external input. They have different uses and may be triggered through heat, UV-light, visible light, electron beam radiation, moisture exposition etc.

For each catalyst I will describe a number of applications where it can be used, although the list is virtually endless. I have chosen the catalysts for their ease of use, price and availability, and have tried to use the safest available. Nevertheless, all precautions on manipulating chemicals apply! These compounds will probably always be noxious, flammable, irritant, and may even cause cellular damage. Use gloves (plastic or rubber gloves will do fine) and I recommend wearing some kind of protective clothes (painter suit or large aprons).

Ultraviolet Photoinitiators

Benzophenones

These molecules contain two aromatic functional groups that adsorb UV light which puts the molecule in an excited state. Together with amines or even alone, they easily form radicals that trigger the polymerization chain reaction. The average concentration of Benzophenone initiators in the polymer blend lies between 1 and 4 weight percent (wt%). High concentrations speed up the hardening process. Lower concentrations allow a better hardening of deep layers. Benzophenones may be used for hardening of Acrylates (together with tertiary Amines), Polyesters and some Epoxy resins.

Benzophenone

(also: Diphenyl ketone or Diphenylmethanone, CAS Nº 119-61-9)

The adsorption spike at 260nm means that it will be triggered by fairly energetic UV light. Energetic UVs tend to travel less deep into the material and remain in the surface boundary, where it is adsorbed very fast. This initiator is to be used in combination with others that adsorb longer wavelengths. It may also be used together with tertiary Amines for Acrylate blends or any mixes that suffer surface radical scavenging from air-oxygen. Benzophenone is a fairly safe compound to use.

Benzophenone at ACROS Organics

Benzophenone at ABCR

Benzophenone at Sigma Aldrich

Michler's Ketone

(also: 4,4'-Bis(dimethylamino)benzophenone, CAS Nº 90-94-8)

The broad adsorption spike at 380nm and above of this initiator allows it to react at deeper levels of polymer. This is an ideal initiator to mix with Benzophenone, for a fast combined surface and deep curing reaction. Caution! Michler's Ketone has a higher health hazard than Benzophenone. Use gloves and mix it in ventilated areas.

Michler’s ketone at Sigma Aldrich

Michler’s ketone at ACROS Organics

Michler’s ketone at ABCR

Fillers

Go to Fillers section

Formulation Examples

Glossary of Terms and Definitions

Here you will find a short and basic explanation of terms used in all the sections above. If some term used above seems unclear to you, please post a message in the forum and I will see to add the term to this glossary.

Go to Glossary
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