No abstract

Applications of magnetic and fluorescent poly(ε-caprolactone) (PCL) is increased rapidly in the biomedical engineering field as a bioimaging probe. This urged us to do the present work. In the present investigation, the role of Fe 3 O 4-AR dye nanohybrid on the ring opening polymerization (ROP) of CL was studied at different experimental conditions such as variation in [M] and [M/I]. Prior to ROP of CL, the nanohybrid was characterized by various spectral methods like FTIR spectroscopy, UV-visible spectroscopy, fluorescence spectroscopy, VSM and FESEM like analytical techniques. The Fe 3 O 4-AR nanohybrid is used as an initiator for the ROP of CL. After the formation of PCL/Fe 3 O 4-AR nanocomposite again the systems were characterized by FTIR spectroscopy, UV-visible spectroscopy, fluorescence spectroscopy, DSC, VSM and FESEM like methods. The interesting point noted in the present investigation is the size of Fe 3 O 4 nanoparticle was found to be reduced after the nanohybrid and nanocomposite formation. The three functional groups of AR dye were involved in the ROP of CL. The binding constant and number of binding sites were determined.

ABSTRACT:The ring-opening polymerization of ɛ-caprolactone and morpholine mixture was carried out at 160°C for 24 h under nitrogen atmosphere at two different experimental conditions, mercaptoaceticacid (MAA) and Ag-MAA initiator variation. The resultants were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, gel permeation chromatography, and high-resolution transmission electron microscopy techniques. The tensile strength of the copolymer nanocomposites was tested. The catalytic reduction behavior (reduction of nitrophenol into amino phenol), splinting activity, and drug delivery activity of the copolymer nanocomposite were tested. The obtained results were analyzed and critically compared. C

The paper describes the synthesis of vinyl ester resins based on diglyeidyl ether of bisphenol-A (epoxy equivalent = 450-465 g/eq) (VR resin) and tetrahromobisphenol-A (epoxy equivalent = 380-420 g/eq) (VR-1 resin). The viscosity of styrenated VR resin was higher than VR-1 resin. The effect of styrene and or-methyl styrene on curing of VR resins was studied. An increase in styrene from 30 to 50 wt% resulted in an increase in gel time and a deerense in exothermic peak. Addition of or-methyl styrene delayed and depressed the exotherm. The mechanical properties of VR resin sheets and glass fabric reinforced laminates were better than VR-1 resins; whereas LOI of VR-I was higher. A resin formulation containing 20-30 wt% of VR:VR-I showed optimum mechanical properties and LOI.

No abstract