PH-Induced Electrostatic Interaction between Polyacrylates and Amino-Functionalized Graphene Oxide on Stability and Coating Performances.

Wenbo Zhang,Jianzhong Ma,Chao Liu,Yingke Wu,Hongxia Yan,Sichun Li

doi:10.3390/polym13193406

Abstract

Electrostatic interaction between polymers and nanofillers is of great importance for the properties and design of their composites. Polyacrylates with carboxyl, hydroxyl and acylamino groups were synthesized via emulsion polymerization and marked as P(MMA-BA-AA), P(MMA-BA-HEA) and P(MMA-BA-AM), respectively. Amino-functionalized graphene oxide (NGO) was prepared by Hoffman rearrangement using GO as the raw material. The polyacrylate composites were prepared by mixing NGO with each of the three kinds of polyacrylate. Effects of pH and NGO amounts on the properties of polyacrylate composites were studied. It was found that the surface charge of polyacrylate and NGO had the greatest effect on the composite properties. P(MMA-BA-AM)/NGO was not stable at any pH (2–8). With the same NGO amount of 0.1 wt%, the toughening effect of NGO on P(MMA-BA-AA) was larger than that on P(MMA-BA-HEA). The break strength of P(MMA-BA-AA)/NGO and P(MMA-BA-HEA)/NGO increased to 5.22 MPa by 47% and 3.08 MPa by 31%, respectively. NGO could increase the thermal stability of P(MMA-BA-AA) and P(MMA-BA-HEA) to different degrees. The polyacrylate film-forming processes were tested, and it showed that NGO influenced polyacrylate through the whole film-forming process. The results provide potential methods for the design of polymer-based nanocomposites.

Highlights

Polymer based graphene composites is an important application field because graphene could increase the properties of composites such as mechanical properties [1,2], electrical performances [3,4], thermal properties [5,6], barrier properties [7,8], flame retardancy [9,10], biomedical applications [11,12], etc
The results showed that the performances of the polyacrylate/NGO composite were improved by blending and pH adjusting
As for the P(MMA-BA-AA), the absorption peaks that appear at 1164 cm−1 and 1724 cm−1 belong to the stretching vibration of C=O

Summary

Introduction

Polymer based graphene composites is an important application field because graphene could increase the properties of composites such as mechanical properties [1,2], electrical performances [3,4], thermal properties [5,6], barrier properties [7,8], flame retardancy [9,10], biomedical applications [11,12], etc. The performances of polymer composites changed greatly by graphene itself or by the synergistic effect of graphene and polymer. Dispersion of graphene or graphene-based nanomaterials in polymers is a hot topic with which researchers are concerned. It is influenced by the interfacial adhesion or interaction between graphene and polymers. The most common method is to graft graphene on a target polymer by covalent bonding. A subsequent in situ polymerization of aniline gave polyaniline covalently grafted on the few-layer graphene surface. In the report of Wu et al [15], polyethylene glycol grafted graphene nanosheets (PEG-g-GO)

Methods

Results

Conclusion