The Effect of SEBS/Halloysite Masterbatch Obtained in Different Extrusion Conditions on the Properties of Hybrid Polypropylene/Glass Fiber Composites for Auto Parts.

Zina Vuluga,Valentin Raditoiu,Catalina-Gabriela Sanporean,Augusta Raluca Gabor,Denis Mihaela Panaitescu,Cristian Andi Nicolae,George Mihail Teodorescu,Mihai Cosmin Corobea

doi:10.3390/polym13203560

Abstract

Masterbatches from a linear poly[styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS) and halloysite nanotubes (HNT-QM) were obtained in different conditions of temperature and shear using two co-rotating twin-screw extruders. The influence of screw configuration and melt processing conditions on the morpho-structural, thermal and mechanical properties of masterbatches at macro and nanoscale was studied. A good dispersion of halloysite nanotubes and better thermal stability and tensile and nanomechanical properties were obtained at a lower temperature profile and higher screw speed. The effect of masterbatches, the best and worst alternatives, on the properties of a polypropylene (PP)–glass fiber (GF) composite was also evaluated. Double hardness, tensile strength and modulus and four times higher impact strength were obtained for PP/GF composites containing masterbatches compared to pristine PP. However, the masterbatch with the best properties led further to enhanced mechanical properties of the PP/GF composite. A clear difference between the effects of the two masterbatches was obtained by nanoindentation and nanoscratch tests. These analyses proved to be useful for the design of polymer composites for automotive parts, such as bumpers or door panels. This study demonstrated that setting-up the correct processing conditions is very important to obtain the desired properties for automotive applications.

Highlights

Polypropylene (PP) is a low-cost thermoplastic polymer with wide application in the packaging, automotive, electronics and construction industries
Our thorough analysis on the influence of halloysite nanotubes–SEBS masterbatches on PP hybrid composites for automotive parts is an attempt to understand the factors that influence the properties of the masterbatch and, further, their effect on the properties of the final composite material
The thermal stability of SEBS/halloysite nanotubes (HNT)-QM masterbatches may be influenced by both processing parameters and screw configuration

Summary

Introduction

Polypropylene (PP) is a low-cost thermoplastic polymer with wide application in the packaging, automotive, electronics and construction industries. Reaching the best properties in PP nanocomposites with montmorillonite (MMT), halloysite nanotubes (HNT) or kaolinite is still a challenge due to the poor dispersion of nanofillers and week adhesion between the hydrophobic PP and high polarity clays [4]. Strategies to overcome this problem have been reported including grafting hydrophilic groups to the polymer matrix, surface modification of nanofillers or coupling agents’ addition [2,3,4,5,6]. Different properties were noticed depending on the treatment and clay type, a consistent improvement of the Young’s modulus being observed only with

Methods

Results

Conclusion