Recyclable Polyethylene Insulation via Reactive Compounding with a Maleic Anhydride-Grafted Polypropylene

Yingwei Ouyang,Oscar Prieto,Thomas Gkourmpis,Xiangdong Xu,Per-Ola Hagstrand,Ida Östergren,Amir Masoud Pourrahimi,Christian Müller,Massimiliano Mauri,Anja Lund

doi:10.1021/acsapm.0c00320

Abstract

The most common type of extruded power cable insulation is based on cross-linked polyethylene (XLPE), which cannot be recycled as a thermoplastic material. Hence, thermoplastic insulation materials...

Highlights

Solar, wind, and hydropower are usually most abundant in unpopulated areas that are located far away from the end user, which necessitates the efficient transport of energy over long distances
One example that illustrates this principle is blending of low-density polyethylene (LDPE) with high-density polyethylene (HDPE).[16−18] We have shown that a few percent of HDPE with a Tm ≈ 130 °C are sufficient to form a continuous network of HDPE crystallites connected via tie chains and trapped entanglements.[16]
In the first set of experiments, we studied the reactivity of p(Estat-GMA) and PP-graf t-MA, which we mixed at a ratio of 4:1 by weight, corresponding to a 1:1 molar ratio of epoxy and carboxyl functional groups in the two polymers

Summary

■ INTRODUCTION

Wind, and hydropower are usually most abundant in unpopulated areas that are located far away from the end user, which necessitates the efficient transport of energy over long distances. We chose to work with a branched statistical ethylene-glycidyl methacrylate copolymer p(E-stat-GMA), which is widely used as a reactive compatibilizer for polymer blends[25−28] and is of promise for byproduct-free cross-linking of PE-based materials.[10−13,29] As the PP material, we selected a maleic anhydride-grafted polypropylene (PP-graf t-MA), which is a common coupling agent, interface modifier, and compatibilizer for PP-based blends and composites[30,31] and displays excellent dielectric properties.[21,32] During compounding of the two copolymers and LDPE, covalent links form that connect p(E-stat-GMA) and (PP-graf t-MA) through reaction between epoxy and carboxyl functional groups. The electrical DC conductivity is not affected by the presence of the various functional groups, in agreement with our recent work on p(Estat-GMA)-based thermosets,[12,13] which opens up a new avenue for the preparation of creep-resistant yet thermoplastic insulation materials

■ RESULTS AND DISCUSSION

■ CONCLUSIONS

■ REFERENCES