Chemically stable polyphenylene ether microcapsules prepared using a facile method for the self‐healing of polymers

Abstract

Chemically stable polyphenylene ether (PPO) microcapsules (MCs) filled with epoxy resins (PPO-EP MCs) were prepared using low-molecular-weight PPO with vinyl end-groups as shell wall and epoxy resins as core material using an oil-in-water emulsion solvent evaporation method. This method for synthesizing MCs with PPO shell walls is simple, convenient and novel, which can avoid the influence of processing parameters on the chemical stability of the epoxy resin core material. The resulting PPO-EP MCs exhibit good chemical stability below 255 ∘ C mainly owing to the absence of a polymerization catalyst of the epoxy resins. The initial thermal decomposition temperature of the MCs is about 275 ∘ C. The MCs were embedded in a 4,4 ′ -bismaleimidodiphenylmethane/O,O ′ -diallylbisphenol A (BMI/BA) thermosetting resin system. When processed at high temperature (up to 220 ∘ C), the microencapsulated epoxy resins could be released from the fractured MCs to matrix crack surfaces and bond the crack surfaces. An amount of 8 wt% MCs restored 91 and 112% of the original fracture toughness of the BMI/BA matrix when heated at 220 ∘ C/2 h and 80 ∘ C/1 h + 220 ∘ C/2 h, respectively. The MCs only slightly decreased the thermal property of the matrix.

Preparation and characterization of high temperature resistant thermosetting polyphenylene ether resin

“…3 Especially in a wide frequency range, PPE owns extremely low dielectric constant and dielectric loss, which makes it an excellent candidate material for electrical or electronic equipment, vehicle parts, business machines, adhesives, coatings and composites. 4,5 However, high-molecular-weight PPE has some shortcomings, such as poor process-ability, highmelt viscosity and low reactivity. Therefore, it needs to be reduced molecular weight to improve the compatibility and processing performance of polyphenylene ether materials with other resins.…”

“…It has the advantages of high heat resistance, high glass transition temperature and low water absorption, and so forth 3 . Especially in a wide frequency range, PPE owns extremely low dielectric constant and dielectric loss, which makes it an excellent candidate material for electrical or electronic equipment, vehicle parts, business machines, adhesives, coatings and composites 4,5 . However, high‐molecular‐ weight PPE has some shortcomings, such as poor process‐ability, high‐melt viscosity and low reactivity.…”