Original Synthesis of Ethylene‐Acrylic Acid (ester) Copolymers Derivatives from 5‐substituted Cyclooctenes with A Controllable Way Via Ring‐Opening Metathesis Polymerization

High‐value grades of ethylene‐acrylic acid (EAA) and ethylene‐acrylic ester copolymers have been producing produced from ethylene, acrylic acid (AA), and the alcohol derivative via radical reaction in autoclave reactor at a temperature of 150‒230 °C and pressure of 150–300 MPa. In this paper, EAA and its ester derivatives are originally created from the 5‐substituted cyclooctenes (COE) with side chains of carboxylic acid or ester derivatives by ring‐opening metathesis polymerization (ROMP) at normal temperature and pressure. Especially, the controllable insertion of side chain is effectively achieved by altering the molar ratio of COE and 5‐substituted COE. Furthermore, the polar carboxyl groups (ester groups) have a detrimental effect on the order assigns of the linear backbone and thus hindered crystallization, indicating relatively lower crystallizing and melting temperature with an increase in the content of side chain. As the amounts of polar groups raised, the stiffness of chain segments enhanced, thereby leading to an elevation in the copolymer's energy storage modulus (E') and glass transition temperature (Tg). Moreover, the Flynn‐Wall‐Ozawa (FWO) technique is employed to characterize and fit the non‐isothermal crosslinking kinetics of the ethylene‐acrylic ester derivatives, and the crosslinking activation energy is determined to lie between 97 and 140 kJ mol−1. 5‐substituted cyclooctenes are used to synthetize ethylene‐acrylic acid (ester) copolymers derivatives via ring‐opening metathesis polymerization. With higher controllable side chain content, the crystallizing and melting temperature lower, energy storage modulus and glass transition temperature grow higher. And the Flynn—Wall–Ozawa method is used to fit the non‐isothermal crosslinking kinetics of ethylene‐acrylic ester copolymer.