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Commercially available recycled ground rubber tire (GRT) particles, found to contain persistent mechano-free radicals confirmed by electron paramagnetic spectroscopy for the first time self-initiates free radical polymerization of acrylic acid (AA). The poly acrylic acid (PAA) grafted GRT (PAA-g-GRT) was confirmed by Attenuated Total Reflection Fourier Transform Infrared spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis (TGA). Epoxy composites using the PAA-g-GRT as filler were prepared and their mechanical properties were studied. The PAA-g-GRT/epoxy composite showed higher mechanical properties with an increase of modulus up to 180% as compared with the neat GRT/epoxy composite. Surface morphology of GRT, neat GRT/epoxy, and PAA-g-GRT/epoxy composites were analyzed by scanning electron microscopy. This technology introduces a new concept to functional and reactive recycling and the cost effective utilization of renewable resource green materials. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers

The curing behavior of diglycidyl ether of bisphenol A (DGEBA) epoxy and specially ground mechanochemical devulcanized ground rubber tire system (GRT) in the presence of polyoxyalkyleneamine curing agent was investigated by non-isothermal differential scanning calorimetry technique at different heating rates. Scanning electron microscopic-energy dispersive X-ray spectroscopy, and attenuated total reflection infrared spectroscopy were used to characterize the GRT particles. The kinetic parameters of curing process were determined by isoconversional method given by Malek. The average activation energy E a was found to be 52.3–60.7 and 45–59.2 kJ/mol for neat epoxy amine (Epo am 31) and epoxy/amine with GRT (5 Epo am 31) systems, respectively. It was observed that the presence of GRT in epoxy/amine promotes the curing. A two parameter (m, n) autocatalytic model (SB equation) was found to be the most adequate to describe the cure kinetics of the studied epoxy/GRT system. A dominant catalyzing effect of GRT on the curing reaction was observed which is attributed to the complexity of the reaction at later stages of curing, therefore, it was not possible to model the reaction over the whole range of degree of conversion.

A statically non-wetting, electrospun surface of non volatile room temperature ionic liquid (RTIL), 1-butyl-3-methylimidazolium hexafluorophosphate, (BMIM-PF 6 ), hosted in a solution-processable, semi-fluorinated perfluorocyclobutyl (BP-PFCB) aryl ether polymer was successfully prepared by electrospinning and compared with a surface prepared by spin casting. The surface properties of undoped and BMIM-PF 6 doped systems were analyzed by water contact angle (WCA) and atomic force microscopy (AFM). BMIM-PF 6 doped BP-PFCB surfaces prepared by spin casting showed a WCA of 90° while non-woven electrospun surfaces with the same BMIM-PF 6 concentration showed high degree of hydrophobicity with a WCA greater than 150°. Morphologies of the electrospun surfaces were characterized by scanning electron microscopy (SEM). The surface composition was analyzed by energy-dispersive X-ray spectroscopy (EDXS) and attenuated total reflectance infrared spectroscopy (ATR-IR). Thermal analysis of the electrospun, non-woven surfaces of the doped and the undoped system of BP-PFCB were done by TGA.

Acrylonitrile/1-vinylimidazole (AN/VIM) copolymers containing various mol% of VIM were synthesized by free radical solution polymerization. The copolymers were characterized by Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy, 1H NMR spectroscopy, gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). Char yields of the copolymers were 40–48% as determined by thermogravimetric analysis (TGA) while gel fractions were found to be 90–99% depending upon the composition, temperature and time. The complex viscosity of the precursor copolymers was measured as a function of composition and temperature. 82/18 mol% of AN/VIM copolymer based carbon fiber precursor was successfully processed by solvent-free melt spinning at 192 °C and the melt-spun fiber was characterized by DSC, ATR-IR, and X-ray Diffraction (XRD).

Tensile properties and Izod impact strength of mica-filled composites of poly(butylene terephthlate) (PBT)/polyacrylonitrile-butyl acrylate-styrene (ABAS) were studied at mica concentration range 0 to 0.14 volume fraction, (ϕf). Tensile properties such as tensile modulus, strength, and breaking strain were normalized by dividing the data with the crystallinity (%) of the major component PBT in the composites and the matrix blends. The normalized relative tensile properties were compared with simple models to evaluate the interphase interactions between the matrix (i.e. PBT/ABAS blend) and the dispersed phase mica. Mica reinforced the blend increasing the tensile modulus and strength with mica concentration while the strain-at-break was increased marginally up to ϕf = 0.04 and decreased beyond this ϕf. The impact strength, however, decreased with increase in ϕf due to enhanced matrix stiffening and lack of plastic deformation of the matrix. Scanning electron microscopic studies revealed good dispersion of mica in the composites. The effect of surface treatment with a zirconate coupling agent, NZ-97, on the above properties has also been examined. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Melt rheological properties of poly (butylene terephthlate) (PBT)/poly (acrylonitrile–butyl acrylate-styrene) terpolymer (ABAS)/mica composites were studied at 0.02 to 0.14 vol fraction (Φf) of mica at 518 K. The shear stress vs. shear rate plots was linear and the melts obeyed power law relation. The composites melts were shear thinning. Apparent melt viscosity decreased initially up to Φf = 0.07 the parameter increased with further increase in Φf. Melt elasticity viz. extrudate swell ratio also decreased up to Φf = 0.07 whereas the data increased at Φf > 0.07. Surface treatment of mica particles by zirconate coupling agent, NZ-97, brought about further modification of the rheological properties through enhanced interaction between the matrix and the dispersed phase.

Blends of poly(butylene terephthalate) (PBT) with poly(acrylonitrile-butyl acrylate-styrene) (ABAS) were characterized by differential scanning calorimetry, infrared, thermogravimetric analysis, and wide-angle X-ray diffraction (WAXD) studies. Addition of ABAS polymer to PBT improved the thermal stability of PBT. Infrared studies showed that ABAS polymer chemically interacts with PBT. The crystallization behavior of PBT was modified in the presence of ABAS polymer. The ABAS polymer showed inappreciable effect on melting behavior of PBT but decreased its crystallization. WAXD studies showed some modification in PBT peaks and a peak with increasing intensity corresponding to the β-crystalline form of PBT. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

The mechanical properties such as tensile properties and Izod impact strength of melt compounded poly (butylene terephthlate)(PBT)/Fluorocarbon terpolymer elastomer (FE) blends at FE concentration from 0 to 0.26 volume fraction were studied. With increase in the FE concentrations the tensile properties decreased while the impact strength increased. Good dispersion and adhesion of FE with major phase PBT was shown by the morphological studies. Crystallinity of PBT and interphase adhesion influenced the tensile properties. Use of simple models relating normalized relative tensile parameters where the data were divided by the crystallinity of PBT in the blends and in the matrix, respectively, supported the interphase adhesion. The concentration and the interparticle distance of the dispersed phase FE influenced the impact toughening.

The mechanical properties such as tensile behavior and impact strength of melt mixed poly(butylene terephthlate) (PBT)/acrylonitrile–butylacrylate–styrene (ABAS) terpolymer blends at ABAS contents up to 39 vol % were evaluated. Tensile properties decreased while impact strength was enhanced by the blending polymer. Morphological studies show good dispersion of ABAS into the PBT matrix. The strength properties were dependent on the crystallinity of PBT and interphase adhesion between the phases. The impact toughening was dependent on the blending rubber concentration and interparticle distance of the discrete phase. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1807–1817, 2007