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Gel Formation during the Gilch Synthesis of Poly( p ‐phenylene vinylenes): Evidence of an Unexpected Explanation
Author(s) -
Schwalm Thorsten,
Rehahn Matthias
Publication year - 2008
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.200700439
Subject(s) - polymer chemistry , relaxation (psychology) , phenylene , solubility , polymerization , polymer , quantum entanglement , chemistry , materials science , chemical engineering , organic chemistry , physics , quantum , psychology , social psychology , quantum mechanics , engineering
Gelation of the reaction mixture and insolubility of the poly( p ‐phenylene vinylenes) (PPVs) when isolated at this stage, but complete redissolution of the gel and excellent solubility of the resulting PPVs after further stirring for hours or days, is a phenomenon in Gilch polymerizations that has not been explained so far. It is verified that, in agreement with the literature, specific additives prevent gelation. However, it is also shown that chemical crosslinking is certainly not the reason for gel formation. Instead, it seems to be the consequence of a very high entanglement density in the pristine PPVs, which requires time for relaxation. The mentioned additives seem to support this dis‐entanglement process.