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The fast development of Pickering emulsion systems inspires burgeoning demand on the universal synthesis platform for the surface modification of solid particle emulsifiers. In this work, a mild and convenient "visible light–mediated surface grafting through (VSGT)" strategy is proposed. Through the two-step strategy, silica nanoparticles (SNPs) were firstly modified by vinyl alkoxysilane and then used as the substrate for grafting homopolymer brushes via reversible addition-fragmentation chain transfer polymerization under the irradiation of a compact fluorescent lamp (CFL) light source. The whole process was proceeded at room temperature without tedious conditions and complex operations. Importantly, simply by changing the monomer types, hydrophilic acrylic polymer chains can all be grafted on SNP with controlled chain length and relatively uniform high surface densities including poly(acrylic acid) (PAA), poly(N,N-dimethylacrylamide) (PDMA), poly(N-isopropylacrylamide) (PNIPAM), and poly(diacetone acrylamide) (PDAAM). Through the synthesis platform, the interfacial performance of the surface-grafted nanoparticles exhibited as amendable working as Pickering emulsifiers in oil–water system, illustrated by the evolution of interfacial tensions and the inner structures of the corresponding Pickering emulsions. Moreover, the emulsion stabilized by SNP-g-PAA and SNP-g-PNIPAM showed pH and temperature triggered emulsification-demulsification behaviors, respectively, convincing the contribution of the surface grafted polymers and provide a feasible clue for the subtle design on the interfacial texture in advanced Pickering emulsions. [ABSTRACT FROM AUTHOR]

Latex polymers with precisely designed dynamic mechanical behavior are the key for waterborne damping coatings, which are widely desired in noise and vibration reduction with additional environmental benefits. In this work, we synthesized series of polymer latexes with various crosslinking agents (CA) and network distributions through the control on emulsion polymerization processes. We have revealed that the variation on crosslinking can significantly direct the latex behavior under dynamic conditions as well as its films. The variables involve the CA composition, the functionality, the crosslinking manner, the hydrophilic‐hydrophobic feature as well as the feeding method. Although all the latex films showed the damping peaks locating in the range from −10 to 70°C, their damping behaviors were quite different. Suggested by the empirical parameters of LA and TA, the product from sequential monomer feeding method tended to give good extensional damping performance. Especially when the crosslinking of diacetone acrylamide (DAAM)/adipic dihydrazide was applied, there was a linear increase on LA with the increasing dosage of DAAM from 0 to 10 mmol in the final monomer addition batch. Meanwhile, good constrained layer damping is expected on the products from the power monomer feeding method with the maximum CA dosage shown below 7.5 mmol. The best TA was achieved when the CA of divinylbenzene was used in the dosage of 5 mmol. These results would be valuable to be referenced in the engineering on organic damping materials toward modern industrial and vehicles applications. [ABSTRACT FROM AUTHOR]

ABSTRACT Fluorinated siloxane-acrylate polymer latex was synthesized via miniemulsion polymerization, which was carried out by pseudo one-step method. In the synthesis protocol, the monomers of octamethylclotetrasiloxane (D4), tetravinyltetramethylcyclotetrasiloxane (D4v), methyl methylacrylate, butyl acrylate, N-methylol acrylamide, and dodecafluoroheptyl methacrylate (DFMA) were first mixed and homogenized into a miniemulsion, which was stabilized by dedecybenzene sulfonic acid. The ring-opening polymerization of cyclosiloxane was then steadily performed under miniemulsion conditions and followed by the postaddition of radical initiators to initiate the polymerization of acrylate and DFMA monomers. The influences on the emulsion properties by acrylic monomer with different addition protocol were investigated in this work. In addition, the synthesized latexes were characterized by using dynamic laser scattering, transmission electron microscope, differential scanning calorimetry, and Fourier transform infrared spectroscopy. These results indicated that the introduction of D4v in the latex can successfully suppress the phase separation between the thermodynamically incompatible components for the formation of uniform hybrid latex particles. The further application of the as-synthesized latex was investigated as a new kind of waterborne textile finishing agent. Moreover, the influences of the content of D4v and DFMA on the finishing properties, especially for the softness, the water repellence, and the antimoisture properties, were systematically studied in this work. With a proper design on the content of the D4v and DFMA, stable textile finishing emulsion was prepared, which can endow the fabric both desirable softness and excellent water resistances. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40161. [ABSTRACT FROM AUTHOR]

A novel epoxidized hyperbranched poly(phenylene oxide) (EHPPO) is designed and synthesized successfully. The structure of EHPPO is characterized by Fourier transform infrared spectra- and quantitative 13C nuclear magnetic resonance spectrum. The synthesized EHPPO is added into diglycidyl ether of bisphenol A as a modifier in different ratios to form hybrids and cured by an anhydride curing agent. Effects of EHPPO addition on the properties of the cured hybrids are investigated. Thermal mechanical analysis results suggest that addition of EHPPO can increase the free volume of the cured hybrid materials. Dynamic mechanical analysis characterizations show that the crosslinking density increases with the increase in EHPPO content. Furthermore, addition of EHPPO results in an improvement in thermal and mechanical properties. The toughening mechanism is also discussed. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]