Effects of halloysite nanotubes modified by organic phosphate on the performance improvement for polypropylene

Abstract

AbstractThe enhancement of halloysite nanotubes (HNT) for polymer mechanical performance is limited due to the poor compatibility with matrix. In this work, hydrophobic 2,2′‐methylene‐bis‐(4,6‐di‐tert‐butylphenyl) organic phosphate (MBP) with multiple methyl groups was firstly used for HNT compatibilization modification. The hydrophobicity transition of modified HNT (HNT‐M) and the dispersibility difference in isotactic polypropylene (iPP) matrix were distinguished by water contact angle and SEM analyses, respectively. In addition, the binding energy evaluated the interfacial interaction and compatibility with matrix before and after modification by molecular dynamic simulation. Correspondingly, the iPP performance was optimized after addition of HNT‐M. The onset decomposition temperature of system at 5% and 10% weight loss was increased by 7 and 11°C compared with neat iPP, respectively. Moreover, the flexural modulus and impact strength of iPP/HNT‐M system were 18.9% and 9.6% higher than neat iPP showing simultaneous enhancement. In addition, iPP/HNT‐M system crystallized begin at higher temperature showing enhanced crystallization ability. Furthermore, the faster crystallization process and more uniform spherulite size were obtained. As a result, the enhancement for iPP performance was obtained when the compatibility between HNT and matrix was improved through surface modification.