Effect of uncoated calcium carbonate and stearic acid coated calcium carbonate on mechanical, thermal and structural properties of poly(butylene terephthalate) (PBT)/calcium carbonate composites

Abstract

PBT/CaCO 3 composites were prepared in a single screw extruder with particle content varying from 0-30% by weight. The influence of surface treatment of the particles, with and without stearic acid (SA), on the mechanical, thermal and structural properties was studied. The experiments included tensile tests, impact tests, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy. The composite systems containing SA coated CaCO 3 were found to exhibit better mechanical properties as compared to composite systems containing uncoated CaCO 3 , with the S3 system (20% of SA coated CaCO 3 ) exhibiting best combination of mechanical properties. Thermal study revealed that particle type and content had no influence on the melting temperature but the crystallization temperature, % crystallinity and thermal stability increased on increasing the CaCO 3 content in PBT matrix. Morphological observation indicated that in PBT composites containing SA coated CaCO 3 , the coupling agent favours a better polymer filler interaction rendering inorganic polymer interface compatible, which is also evident from better mechanical and thermal properties.

Analysis of the effect of chalk modification on the peculiarities of its interaction with acrylic film former

“…[9] investigated the modification and processes of interaction between the surface of СаСО 3 and SAS in more detail; this article, however, addressed the nanofillers only. There are also results of studies about the effect of treating the СаСО 3 particles surface with stearin acid by the Fourier infrared spectroscopy method [10].…”

Investigation of the modification process of natural sedimentary calcite by organosilicon compounds

“…Modifiers of the first type, namely stearic acid, are the most com mon and, therefore, wellstudied, which is reflected in the number of papers devoted to this process [2][3][4]. Modifiers of other types are used less often, but often are specific for those polymers in whose matrices it is planned to further use the modified filler.…”

Mechanical and Thermo-Physical Properties of Short Glass Fiber Reinforced Polybutylene Terephthalate upon Aging in Lubricant/Refrigerant Mixture

“…It was used sealed aluminum crucibles, and samples mass of about 14 mg. Crystallinity degree was calculated from equation 5, based on a theoretical 100% crystalline PBT heat of fusion of 140 J/mol 19,20 .…”

“…Typical IR bands of non-aged PBT appear at wavenumbers of 1707 cm -1 (carbonyl stretch), 1456 cm -1 (C-H bending in CH 2 group), 1407 and 1018 cm -1 (aromatic ring), 1241 cm -1 (CO-O stretch in esters), 1115 cm -1 (O-CH 2 ), and 723 cm -1 (aromatic C-H bending) 19,28 . As shown in Figure 7, no major changes between different PBT spectra can be noticed.…”

“…This new melting peak is also observed in the control samples DSC thermogram. It is well known from literature 19,26 that multiple peaks phenomenon is usual from PBT calorimetry analyses and can be attributed mainly to thermal history of the polymer. According to Hobbs 27 , the appearance of a second peak below the original peak can occur due to reorganization of crystalline structure or recrystallization of previously By periodically measuring this ratio, it was possible to plot the graph in Figure 8, which shows the developing of the crystallinity index during aging tests.…”