Frontal polymerization

Frontal polymerization (more precisely thermal frontal polymerization) is a method for the production of polymers , which is characterized by the fact that the synthesis reaction spreads in the form of a moving front.

Starting from the first description of the phenomenon, a propagating polymerization reaction, the scientific investigation of the method is of growing interest, especially because of the low energy input. In addition to other special variants, the thermal frontal polymerization of radical polymerization reactions is the most important and most investigated. (Overview of scientific literature on the topic)

Schematic sequence of a frontal polymerization

With a frontal polymerization, a thermal front is generated in a monomer formulation (monomer, initiator, possibly solvent, additives or fillers) at one point by a single input of energy. This propagates itself in the reaction vessel, creating the desired polymeric product.

The method is based on the fact that polymerization reactions are in some cases strongly exothermic. Since small monomer units react to form macromolecules during polymerization , the order in the system increases and the Gibbs-Helmholtz equation has a positive entropy term . Since reactions only take place when the free Gibbs energy is negative, this can only be achieved with a correspondingly high exotherm . If the setting is designed accordingly with regard to heat loss / dissipation, a reaction can maintain itself and spread in a controlled manner.

Web links

http://pojman.com/FP_Bibliography.html

Individual evidence

↑ BB Khanukaev, MA Kozhushner, NS Enikolopyan, NM Chechilo: Theory of the propagation of a polymerization front . In: Combustion, Explosion, and Shock Waves . tape 10 , no. January 1 , 1974, ISSN 0010-5082 , pp. 17-21 , doi : 10.1007 / BF01463779 .

↑ JA Pojman: Frontal Polymerization . In: Polymer Science: A Comprehensive Reference . Elsevier, 2012, ISBN 978-0-08-087862-1 , pp. 957-980 , doi : 10.1016 / b978-0-444-53349-4.00124-2 .

[1] BB Khanukaev, MA Kozhushner, NS Enikolopyan, NM Chechilo: Theory of the propagation of a polymerization front . In: Combustion, Explosion, and Shock Waves . tape 10 , no. January 1 , 1974, ISSN 0010-5082 , pp. 17-21 , doi : 10.1007 / BF01463779 .

[2] JA Pojman: Frontal Polymerization . In: Polymer Science: A Comprehensive Reference . Elsevier, 2012, ISBN 978-0-08-087862-1 , pp. 957-980 , doi : 10.1016 / b978-0-444-53349-4.00124-2 .