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Polystyrene-grafted attapulgite (ATP-g-PS) was prepared using surface-initiated redox initiation via graft from approach. ATP was modified with (3-aminopropyl) triethoxysilane (APTES) to anchor amine on the surface (ATP-N[H.sub.2]), and then ATP-N[H.sub.2] was further treated with 4-(diethylamino) salicylaldehyde (DEAS) to give aromatic tertiary amine groups functional ATP (ATP-ATA). Subsequently, the surface-initiated redox polymerization of styrene in the presence of ATP-ATA and benzoyl peroxide (BPO) was performed to afford ATP-g-PS. The chemical grafting of PS on the surface of ATP was confirmed by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The crystal structure of PS-grafted ATP was characterized by X-ray diffraction (XRD) analysis. The morphology of ATP-g-PS was observed by scanning electron microscopy (SEM). POLYM. ENG. SCI., 55:889-895, 2015. [C] 2014 Society of Plastics Engineers, INTRODUCTION Nowadays, inorganic nanoparticles are widely used in polymer to endow the multiphase system excellent properties by utilizing mechanical, biochemical, and thermal characteristics of inorganic nanoparticles [1-4]. The exceptional properties [...]

In this work, the thiolized attapulgite (ATP-MTS) particles were prepared by the dealcoholation between hydroxyl and γ-mercaptopropyltrimethoxysilane (MTS). Then, based on the 'grafting from' mechanism, the surface-initiated graft polymerization was carried out to give ATP grafted with polymethyl methacrylate hybrid particles (ATP@PMMA). The grafting process was characterized in detail by FTIR, TGA, XRD, XPS, TEM and elemental analysis. The effects of the main polymerization conditions on the grafting ratio were investigated in detail. Finally, polycarbonate (PC) was modified with ATP@PMMA to investigate the effects of hybrid particles on the processability of nanocomposites. The results showed that ATP@PMMA particles with a maximum graft ratio of 23.3% were prepared successfully within 5 h. The optimum polymerization temperature was 60°C, and the ratio of MMA/SH/AIBN was 500/2/1. The surface tailoring improved the dispersion of ATP@PMMA in the matrix. Compared with the pristine PC, the incorporation of ATP@PMMA enhanced the melt flow index (MFI), while reduced the glass transition temperature (Tg) and complex viscosity of nanocomposites. [ABSTRACT FROM AUTHOR]

AbstractTo further improve the comprehensive properties of polycarbonate/acrylonitrile–butadiene–styrene terpolymer blends (PC/ABS), in this work, styrene–acrylonitrile copolymer [P(St-co-An)] was grafted on the surface of attapulgite particles (ATP) by simultaneous reverse and normal initiation ATRP (SR&NI ATRP) to yield ATP@P(St-co-An) hybrid particles. Then a series of PC/ABS/ATP@P(St-co-An) composites were prepared via the melt blending method. The effects of ATP@P(St-co-An) content on the morphological, mechanical, thermal and rheological properties of the composites were investigated in detail. The core-shell ATP@P(St-co-An) hybrid particles with the polymer layer thickness of 20-40 nm were synthesized successfully according to the results of X-ray photoelectron spectrometer (XPS), Fourier transform infrared spectrometer (FTIR), gel permeation chromatography (GPC), thermogravimetric analysis (TGA) and transmission electron microscopy (TEM). The improvement in mechanical properties, reduced glass transition temperature (Tg) difference between PC and ABS and micromorphology changes of the composites proved the compatibilization, strengthening, and toughening effect of the ATP@P(St-co-An). Compared with the PC/ABS blend, with strength and toughness of 50.8 MPa and 56.3 kJ/m2, when the ATP@P(St-co-An) content was 4 wt%, a reasonable balance (85.8 MPa and 86.2 kJ/m2) between strength and toughness was achieved with substantially enhanced thermal stability. Moreover, the composite showed more remarkable non-Newtonian behavior, and its processability was also improved. We believe this work provides an effective approach to optimize the compatibility and comprehensive properties of PC/ABS blends. [ABSTRACT FROM AUTHOR]

ABSTRACT The surface grafting of attapulgite (ATP) with polystyrene (PS) was established via a simultaneous reverse and normal initiation atom transfer radical polymerization (SR&NIATRP). 4-(chloromethyl)phenyltrimethoxysilane (CMPTMS) chemical bounded on the surface of ATP (ATP-Cl, Cl-I) was prepared via one-step self-assembly. SR&NI ATRP of styrene was conducted using CuCl2 complex tris(2-(dimethylamino)ethyl)amine (Me6-TREN) as the catalytic system, initiated by 2,2-azobis(isobutyronitrile) (AIBN) and ATP-Cl. FT-IR, XRD, XPS, TGA and TEM data were consistent with the grafting of benzyl chloride groups and PS chains on ATP surface. The controllability of polymerization was investigated by the kinetics behavior under different molar ratio of AIBN and CuCl2. The obtained polymer possessed a uniform distribution of molecular weights with a lower polydispersity index of 1.2∼1.4. The relationship between polymerization on the surface of ATP and in solution was discussed in detail based on TGA data of hybrid particles and GPC trace of free polymer in solution. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 1508-1516 [ABSTRACT FROM AUTHOR]

ABSTRACT A series of polymer-clay nanocomposites consisting of polystyrene (PS) and attapuglite (ATP) were prepared successfully. First, silane coupling agent containing aromatic tertiary amine groups was synthesized to functionalize ATP (M-ATP). Then, PS nanocomposites with varied clay loadings were prepared via in situ suspension polymerization process with a redox initiation system consisting of aromatic tertiary amine and benzoyl peroxide. The synthesis of silane coupling agent and functionalization of ATP were confirmed by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectra, and X-ray photoelectron spectroscopy. Mechanical properties, morphology, thermal stability, and rheological behavior of nanocomposites were investigated to illuminate the effects of M-ATP on the structure and properties of nanocomposites. Field-emission scanning electron microscope images revealed an ideal dispersion of M-ATP and an enhanced toughness of nanocomposites. The improved interface interaction between M-ATP and PS matrix endowed the nanocomposites with outstanding mechanical properties and thermal stability. The formation of hybrid network in the nanocomposites containing 3 wt % M-ATP resulted in higher complex viscosity (η*), storage modulus ( G′), and lower loss factor (tanδ) compared with the pristine PS and PS/ATP nanocomposites. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41567. [ABSTRACT FROM AUTHOR]

ABSTRACT Novel high density polyethylene (HDPE)/SiO2 hybrid materials were prepared by the sol-gel process using tetraethoxysilane (TEOS). HDPE and synthesized HDPE- g-vinyl trimethoxysilane (VTMS) through melt grafting method was used as the raw material. The structure and thermal, mechanical properties of hybrid materials were investigated by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), simultaneous thermogravimetric (TG), differential thermal analysis (DTA), and tensile tests, respectively. Silica phase in the HDPE- g-VTMS hybrids showed a network structure and nano-scale size. The covalent bonds between organic and inorganic phases were introduced by the HDPE- g-VTMS bearing trimethoxysilyl groups, which underwent hydrolytic polycondensation with TEOS. The thermal stability and mechanical properties of HDPE- g-VTMS hybrids were obviously improved by embedded silica networks. It was found that the silica content in the HDPE- g-VTMS hybrid material was linearly increased with the TEOS dosage. The formation of the HDPE -g-VTMS hybrid was beneficial for enhanced mechanical strength and thermal stability, in comparison with the neat HDPE. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 39891. [ABSTRACT FROM AUTHOR]