Influence of oxycycloaliphatic groups in the relaxation behavior of acrylic polymers

Relaxation behavior of acrylate and methacrylate polymers containing dioxacyclopentane rings in the side chains

“…This fact suggests that twist → envelope conformational transitions may not be responsible for the low dielectric activity exhibited by these polymers in the glassy state. It should be stressed in this regard that poly( cis / trans ‐5‐acryloxy‐5‐ethyl‐2‐phenyl‐1,3‐dioxane)30 also exhibits low subglass dielectric activity in comparison with poly(5‐acryloxy‐5‐ethyl‐1,3‐dioxane)31 (see Fig. 11), although the barrier energies associated with the conformational transitions in the 1,3‐dioxane rings are similar for both polymers.…”

Fragmentation of Carbohydrate Anomeric Alkoxyl Radicals: New Synthesis of Chiral 1‐Fluoro‐1‐halo‐1‐iodoalditols

“…Recently, the dielectric activity of polymers containing 1,3‐dioxane groups was analyzed 15, 24, 25. Poly(5‐acryloxymethyl‐5‐ethyl‐1,3‐dioxane)24, 25 presents a single prominent subglass relaxation, the intensity of which sharply decreases if the equatorial hydrogen located in the carbon atom in position 2 is replaced by a phenyl group. Because dielectric activity is related to motions of polar entities, subglass dielectric relaxations displayed by acrylate and methacrylate polymers must be related to motions of the side groups in such a way that the easier these motions are, the higher the subglass absorptions must be.…”

Relaxation response of polymers containing highly flexible side groups monitored by broadband dielectric spectroscopy

“…The complexity of the molecular motions of the side chains is greatly enhanced by the replacement of a hydrogen atom of the methyl group of poly͑methy-lacrylate͒ with the 5-methyl-1,3-dioxacyclohexane moiety. [9][10][11] Since the C͑O͒-O bond of the ester group is restricted to the trans state, dielectric activity may arise from motions about the -CH 2 C͑O͒O-CH 2 -C y bonds coupled with both chair-to-inverse chair-conformational transitions occurring in the methyl-1,3-dioxcyclohexane ring and local motions of the skeletal bonds. The barrier energy involved in the conformational transition of the dioxacyclohexane ring has been calculated using molecular-dynamics simulation methods of 5,5-dimethyl-1,3-dioxacyclohexane.…”

“…A description of the synthesis of both monomer and polymer is given elsewhere. 11 A scheme of the repeating unit of PAMMD is shown in Fig. 1.…”