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Photopolymerization of difunctional cyclopolymerizable monomers with low shrinkage behavior
Author(s) -
Ruppitsch Larissa Alena,
Peer Gernot,
Ehrmann Katharina,
Koch Thomas,
Liska Robert
Publication year - 2021
Publication title -
journal of polymer science
Language(s) - English
Resource type - Journals
eISSN - 2642-4169
pISSN - 2642-4150
DOI - 10.1002/pol.20200863
Subject(s) - shrinkage , photopolymer , monomer , polymer chemistry , polymer science , chemistry , materials science , chemical engineering , organic chemistry , composite material , polymer , engineering
Cyclopolymerizable monomers (CPM) have been the focus of investigations for over 70 years due to favorably low shrinkage upon polymerization, yet little research dealt with difunctional CPMs, especially in the field of radical photopolymerization. Herein, we synthesized novel difunctional 1,6‐diene CPMs based on the isomeric mixture of (2,2,4)/(2,4,4)‐trimethylhexane‐1,6‐diamine as spacer unit, which undergoes cyclopolymerization forming five‐ or six‐membered ring structures in the polymer backbone upon photopolymerization. Different photopolymerizable moieties (allyl‐, methacryloyl‐, and ester‐activated allyl‐moieties) were chosen for modification of the spacer unit to investigate their influence on reactivity and shrinkage behavior. The (thermo)mechanical properties of the cured difunctional 1,6‐diene CPMs further reveal the effect of reactivity‐enhancing electron‐withdrawing groups (e.g., ester and carbonyl groups) on the final polymer network. For comparison, similar difunctional monoene compounds were are also synthesized and characterized to illustrate the low shrinkage behavior of the novel difunctional 1,6‐diene CPMs.