Polystyrene−Calcium Phosphate Nanocomposites: Preparation, Morphology, and Mechanical Behavior

Abstract

Calcium phosphate nanoparticles were prepared by matrix-mediated synthesis and were characterized using X-ray diffraction and transmission electron microscopy techniques. The particle size was found to be around 10 nm. Nanocomposites of polystyrene with calcium phosphate were prepared by a melt mixing technique. Mechanical properties of the nanocomposites such as tensile strength, tensile modulus, elongation at break, and impact strength were determined. Tensile strength and modulus showed 50 and 80% increase for 5% filled composites, respectively. Careful differential scanning calorimetric measurements were performed to evaluate the changes in heat capacity (C p ) as a function of filler loading. The ΔC p values decreased dramatically as a function of filler loading indicating the existence of strong interaction between the nanofiller and polystyrene. A three-phase model consisting of a rigid amorphous phase has been proposed to illustrate the strong polymer−filler interaction.

Chitosan composites with nanohydroxyapatite prepared by wet chemical reaction along with microwave irradiation: permeability and swelling aspects

“…6. The FTIR results of the HA/CS composites confirmed the presence of the polymeric phase of typical bands of CS, namely the amide group at 3467 and 1643 cm 21 , and the weaker amino characteristic peak at 1581 cm 21 . In addition, the IR spectrum also displays the peaks at 894 and 1150 cm 21 attributed to the saccharine structure and aliphatic C-H stretching bands in the region of 2921 cm…”

“…The synthesized powder as well as the composites was scanned in the range of 400-4000 cm 21 in a Nicolet 5700 FTIR Spectrometer. For pure nHA powder, KBr pellet technique was used.…”

“…2. The presence of phosphate group was confirmed by the presence of strong, complex band of PO 21 were assigned to stretching (s) and bending (b) hydroxyl group, respectively [54].…”

“…The more intense and broad absorption bands in the CS are assigned to the -OH groups located around 3282 cm 21 . The FTIR of the inorganic phase revealed the presence of the bands at 559 cm 21 , and a single intense band at 1020 cm 21 , which are typically attributed to the phosphate groups of HA with the frequency of vibration m4 and m3, respectively. Peak at 1643 cm 21 represents acetylated amino group of chitin, which indicates that the sample is not fully deacetylated.…”

“…The FTIR of the inorganic phase revealed the presence of the bands at 559 cm 21 , and a single intense band at 1020 cm 21 , which are typically attributed to the phosphate groups of HA with the frequency of vibration m4 and m3, respectively. Peak at 1643 cm 21 represents acetylated amino group of chitin, which indicates that the sample is not fully deacetylated. Peak at 1376 cm 21 represents the -C-O stretching of primary alcoholic group (-CH 2 -OH) in CS.…”