The Effect of Inorganic Nanoadditives on the Thermal, Mechanical and UV Radiation Barrier Properties of Polypropylene Fibres

Anna Ujhelyiová,Jozef Ryba,Eberhard Borsig,Petronela Vencelová,Mária Slobodová

doi:10.4236/ojopm.2012.22005

Abstract

The objective of this study of modified polypropylene (PP) fibres using nanoadditives (nano-CaCO3 and Cloisite 30B) was to determine the influence of these additives on thermal and mechanical properties, but especially on the barrier properties of the nanocomposite fibres against UV radiation. The DSC data obtained from measurements of PP/CaCO3 or PP/C30B nanocomposite fibres were used for determination of the constants n and K of the Avrami equation and in the estimation of other thermal properties of the fibres, such as their crystallization half-time t1/2, rate of crystallization t1/2, the necessary time for maximum crystallization tmax and free energy per unit area of surface in the lamella perpen-dicular to the axis of a high-molecular chain se. The nano-CaCO3 or Closite 30B fillers (pre-treated separately in three different solvents: glycerine, acetone and water) did not influence the melting temperatures but caused an increase in PP crystallization temperatures in comparison with the pure PP fibres. The pre-treatments of nanoadditives resulted in increase of n, K, t1/2 values and decrease of t1/2, tmax as well as the values of free surface energies per unit area of the modified PP fibres. There was also observed a decrease in the mechanical properties, however, there was an increase of barrier properties against UV radiation of nanocomposite PP fibres in comparison with neat PP fibres, which was one of the main objectives of the study.

Highlights

One of the latest evolutionary ways of preparation of novel polymeric materials is the development of polymer/nanofiller materials with improved properties which allow their application in the manufacture of demanding equipment
The DSC data obtained from measurements of PP/CaCO3 or PP/C30B nanocomposite fibres were used for determination of the constants n and K of the Avrami equation and in the estimation of other thermal properties of the fibres, such as their crystallization half-time t1/2, rate of crystallization 1/2, the necessary time for maximum crystallization tmax and free energy per unit area of surface in the lamella perpendicular to the axis of a high-molecular chain e
The melting temperatures for first and second heating of PP modified by C30B and NanoCaCO3 filler (nCaCO3) and treated by various methods are the same as the melting temperature of pure PP fibre

Summary

Introduction

One of the latest evolutionary ways of preparation of novel polymeric materials is the development of polymer/nanofiller materials with improved properties which allow their application in the manufacture of demanding equipment. The principle underlining the nanofiller effect on polymer matrix is based on the relatively high surface area of nanofiller particles and so possibility creating more intimate interactions with polymer chains. These can lead to crosslinks among polymer chains and throughout the physical polymer network. Incorporation of nanoadditives into a polymer matrix offers an attractive potential for diversification of conventional polymeric materials, such as iso-tactic polypropylene (PP) in various areas of technical application [1,2,3,4,5]. Thanks to the unique nano-size of primary filler particles, they offer some new properties such as transparency, improved abrasion resistance as well as unique colouristic effects. A noteworthy advantage has already been realized from the use of nano-sized filler in that only a small addition of filler significantly increases impact strength as well as toughness of the polymer materials [6]

Methods

Results

Conclusion