Soap-free styrene-acrylic/carbon nanotubes composite latex by in situ emulsion polymerization: Preparation, properties and characterizations

Abstract

Thermoplastic conductive composites, namely, soap-free styrene–acrylic emulsion (S-A)/carbon nanotubes (CNTs) modified with carboxyl (–COOH) groups, were successfully synthesized by an in-situ semi-continuous seed emulsion pre-emulsification polymerization with allyloxy decyl polyoxyethylene ether (10) (KL) as a reactive emulsifier. The fracture surface scanning electron microscopy (SEM) images of the films illustrated that CNTs are inlayed in the S-A matrix and shaped into a conductive network for electron transport. Compared with neat S-A, the performance of the composites was greatly improved. The curing temperature of the composite emulsion with 4 wt% CNT–COOH was dropped by 16.4 °C. The electrical conductivity of the latex film was improved by eight orders of magnitude. The tensile strength and Young's modulus of the film were boosted by 483% and 2475%, respectively. Additionally, water resistance was ameliorated. These enhancements confirmed that the addition of CNTs can strengthen the curing, heatproof, mechanical, electrical, and waterproof properties of the S-A, which provides a new strategy for the modification of waterborne emulsion.