Surface Modification of Nanoclays with Styrene-Maleic Anhydride Copolymers

Refik Arat,Nurseli Uyanık

doi:10.4236/nr.2017.83011

Abstract

This study presents the modification of surfaces of nanoclays, halloysite nanotubes (HNT) and sepiolite (SEP), with styrene-maleic anhydride copolymers (SMA) via esterification reaction between hydroxyl groups of the nanoclays and anhydride groups of SMA. The structural, thermal, and morphological analyses of the modified nanoclays were performed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), thermal gravimetric analysis (TGA), and field emission scanning electron microscopy (FESEM). All of these results suggested that the expected modification of HNT and SEP surfaces were performed. Although XRD patterns of HNT containing samples showed that the basal spacing shifted to higher distances, it was found that those of the crystalline structure of SEP remained unchanged. Thermal gravimetric analysis exhibited that SMA copolymers were grafted onto the surfaces of nanoclays varying amounts between 15 and 43 wt. % depending on the types of nanoclays and SMA copolymers. This modification indicates that these nanoclays can be added to the polystyrene matrix without any compatibilizers.

Highlights

Nanoclays have been employed as fillers in polymers to improve their mechanical performance, thermal stability, barrier properties and flame retardancy [1]-[6]
This study presents the modification of surfaces of nanoclays, halloysite nanotubes (HNT) and sepiolite (SEP), with styrene-maleic anhydride copolymers (SMA) via esterification reaction between hydroxyl groups of the nanoclays and anhydride groups of SMA
Halloysite and sepiolite were modified with styrene-maleic anhydride copolymers via chemical method

Summary

Introduction

Nanoclays have been employed as fillers in polymers to improve their mechanical performance, thermal stability, barrier properties and flame retardancy [1]-[6]. Some silanol (Si-OH) and aluminol groups exist at the edges of the tubes [17] [18] [19] These hydroxyl groups caused polarity on the HNT surface offer an opportunity to obtain efficient dispersion of HNT into the polar polymeric matrices [20] [21]. HNT surface was functionalized with γ-aminopropyltriethoxysilane and PP chains were grafted onto the surface of HNT via commercialized maleic anhydride grafted PP (PP-g-MAH) They found that the modified HNT showed much lower polarity compared to pristine HNT and increased the mechanical properties compared with neat PP and PP/pristine HNT nanocomposites [32]. The modified nanoclays were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), thermal gravimetric analysis (TGA), and field emission scanning electron microscopy (FESEM)

Materials

Characterization of the Modified Nanoclays

Results and Discussion

Conclusion