Composition, hydrogen bonding and viscoelastic properties correlation for ethylene/?,?-alkenol copolymers

The influence of composition of ethylene/alpha,omega-alkenol (alpha,omega-alkenol = 10-undecen-1-ol or 9-decen-1-ol) copolymers on comonomer distribution and dynamic rheological properties were investigated. Thermal fractionation revealed formation of multiple peaks corresponding to the presence of methylene sequences of different length in copolymers. The share of fraction with shorter methylene sequence increased with increasing comonomer content. It turned out that viscoelastic behavior of ethylene/alpha,omega-alkenol copolymers was dependent on comonomer content incorporated into the polymer chain. The relaxation time of reptation increased with increasing comonomer content what confirmed that comonomer units acted as physically crosslinking agent. FTIR investigation proved the appearance of inter- and intramolecular hydrogen bonds in ethylene copolymers with alpha,omega-alkenols. Higher relative content of inter- and intramolecular hydrogen bonds was observed in alpha,omega-alkenol with a longer hydrocarbon chain. In addition, activation energy of flow increased with increasing of the comonomer content. Moreover, incorporation of alpha,omega-alkenols into the polymer chain resulted in a decrease of the packing length of copolymers with increasing comonomer content, what proved that the inter- and intramolecular hydrogen bond played a significant role in viscoelastic properties.

Automated summary

The influence of the composition of ethylene/alpha,omega-alkenol copolymers on comonomer distribution and dynamic rheological properties was investigated. The results showed that the copolymers contained different lengths of methylene sequences, and the viscoelastic behavior of the copolymers depended on the content of alpha,omega-alkenol. FTIR investigation confirmed the presence of inter- and intramolecular hydrogen bonds in the ethylene copolymers. The incorporation of alpha,omega-alkenols into the polymer chain led to a decrease in the packing length of the copolymers.