Premium
Synthesis, thermal, and rheological properties of poly(trimethylene terephthalate)/BaSO 4 nanocomposites
Author(s) -
Yao Chenguang,
Yang Guisheng
Publication year - 2009
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/pat.1313
Subject(s) - materials science , crystallinity , thermogravimetric analysis , nanocomposite , differential scanning calorimetry , thermal stability , chemical engineering , in situ polymerization , polymer chemistry , crystallization , polymerization , endothermic process , composite material , polymer , organic chemistry , chemistry , physics , adsorption , engineering , thermodynamics
A novel method was developed for fabricating poly(trimethylene terephthalate) (PTT)/BaSO 4 nanocomposites using in situ polymerization. A nano‐BaSO 4 suspension was prepared by reacting H 2 SO 4 with Ba(OH) 2 in 1,3‐propanediol (PDO). The mean size of original nano‐BaSO 4 is 15–23 nm. PTT matrix was synthesized by condensation polymerization of bis(3‐hydroxypropyl terephthalate) after the completion of transesterification of dimethyl terephthalate (DMT) with PDO. It was found that the addition of BaSO 4 had little influence on the synthesis of PTT. The properties of nanocomposites with a wide range of BaSO 4 fraction were systematically studied. The morphologies of the composites were investigated by transmission electron microscopy (TEM), which showed that agglomerate structures did not form until BaSO 4 content higher than 8 wt%. The thermal properties of the nanocomposites were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The DSC results revealed that the triple endothermic melting phenomenon is only observed for the nanocomposites which contained 4 wt% BaSO 4 , other samples exhibit double endothermic melting. These results indicated that nano‐BaSO 4 could induce a microcrystal to form more perfect morphology and restrain the formation of much thicker lamellar crystallinity, that is, nano‐BaSO 4 could induce the formation of more uniform crystallinity. Besides, the crystallization ability of the composites was greatly improved by loading nano‐BaSO 4 . The TGA results suggested that nano‐BaSO 4 slightly increased the maximum‐decomposing‐rate temperature 1 ( T max1 ), but markedly increased the maximum‐decomposing‐rate temperature 2 ( T max2 ). Furthermore, the steady‐state shear behavior of samples was investigated by a parallel‐plate rheometer. The storage modulus ( G ') and loss modulus ( G ”) curves shifted to higher modulus upon addition of 2–16 wt% of nano‐BaSO 4 . All of the samples investigated exhibited the expected shear‐thinning behavior. Proper contents of nano‐BaSO 4 would decrease the shear viscosity of nanocomposites, whereas superfluous amounts would greatly increase the viscosity of nanocomposites and the composites which loaded 8 wt% nano‐BaSO 4 revealed an equivalent shear viscosity compared to pure PTT. Copyright © 2008 John Wiley & Sons, Ltd.