Mechanochromic materials have recently received tremendous attention because of their potential applications in humanoid robots, smart windows, strain sensors, anti-counterfeit tags, etc. However, improvements in device design are highly desired for practical implementation in a broader working environment with a high stability. In this article, a novel and robust mechanochromism was designed and fabricated via a facile method. Silica nanoparticles (NPs) that serve as a trigger of color switch were embedded in elastomer to form a bi-layer hybrid film. Upon stretching under ambient conditions, the hybrid film can change color as well as transparency. Furthermore, it demonstrates excellent reversibility and reproducibility and is promising for widespread application.

A series of acrylonitrile-butadiene-styrene (ABS) copolymer/poly(butylene terephthalate) (PBT)/acrylonitrile-styrene-glycidyl methacrylate (ASG) blends with various compositions were prepared and characterized in this study. When the fraction of ABS exceeds a critical value there is a rapid increase in notched impact strength of ABS/PBT blends no matter whether the compatibilizer ASG is present. By combining morphology observation and notched impact results, we found that the ductile-brittle transition of the blends is closely related to the morphology inversion. The notched impact strength jumps from 15.9 to 33.4 kJ/m 2 when phase inversion of ABS occurs at its fraction of 58 wt %. Accordingly, a possible toughening mechanism involved in the blends is proposed on the basis of a careful analysis of fracture energy, crack propagation behavior and fracture surface morphology. It is believed that the continuous ABS phase plays the critical role in toughening ABS/PBT blends.

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Organic nano-silica was firstly synthesized by sol-gel method with methyl methacrylate (MMA) and butyl acrylate (BA) in the micelles as dispersing media, tetraethoxysilicate (TEOS) as precursor, hydrochloric acid as catalyst and methacryloylpropyl trimethoxysilane (A174) as modifier. Subsequently, the nano-silica/polyacrylate composite emulsions were directly prepared by in-situ emulsion polymerization under the action of the initiator. The structure and properties were characterized by Fourier transform infrared spectroscopy (FTIR), dynamic light-scattering (DSL), thermogracvimetry (TG) and transmission electron microscopy (TEM). The results showed that A174-modified nano-silica was successfully synthesized in the acrylate-based emulsions by the sol-gel method. The nano-silica was encapsulated by polyacrylate, and the composite latex particles exhibited an apparent core-shell structure. The A174 could improve the lipophilicity of nano-silica and increase the grafting efficiency of polyacrylate on nano-silica particles. The nano-silica/polyacrylate composite latex film had better thermal stability, and the composite latex particles had greater average size and broader size distribution in contrast to those of pure polyacrylate emulsions.

Polyacrylate/polymerized rosin composite emulsions were prepared by seeded semicontinuous emulsion polymerization of acrylate monomers in which polymerized rosin was dissolved. The effects of polymerized rosin content on the polymerization stability, monomer conversion, polymer structure, and adhesive properties were studied. Polyacrylate/polymerized rosin composites were characterized by gel permeation chromatograph (GPC), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogracvimetry (TG). The results showed that with an increase of polymerized rosin content from 0 to 6 wt %, gel fraction and sol molecular weight decreased obviously but monomer conversion was basically unchanged. In contrast, with a further increase of polymerized rosin content, the decreasing rates of gel fraction, and sol molecular weight were slowed down. Meanwhile, monomer conversion decreased remarkably. Moreover, interface failure changed into cohesive failure after the addition of polymerized rosin, and the peel adhesion and shear resistance of composite latex films declined with the increase of polymerized rosin content. Thermal analysis showed that polymerized rosin and polyacrylate were compatible and the composite latex films had good thermal stability.

2015) Effect of hydrogenated acrylic rosin on structure and properties of polyacrylates emulsions by seeded semibatch emulsion polymerization method, Journal Hydrogenated acrylic rosin (HAR)/polyacrylate composite emulsions were prepared by seeded semibatch emulsion polymerization method. The effect of HAR amount on monomer conversion rate, coagulum rate, and gel fraction of the composite emulsions as well as the water absorption ratio, adhesion properties, and thermal durability of the HAR/polyacrylate composite latex films was studied; the composites were also characterized by Fourier transform infrared spectroscopy (FT-IR), gel permeation chromatograph (GPC), differential scanning calorimetry, and thermogravimetry. The results showed that with the increase of HAR amount, the monomer conversion rate, gel fraction, molecular weight, and water absorption ratio were all decreased, and the coagulum rate and molecular weight distribution increased. HAR had good compatibility with polyacrylate, and when HAR amount was 4 wt%, the HAR/polyacrylate composite latex film had superior adhesion properties and thermal durability.

Polyacrylate microspheres with a hollow structure were prepared by a facile spray drying method. The effects of spray drying process parameters, including inlet temperature, atomizer rotational speed, and feed speed, on the particle size, bulk density, and morphology of the resultant polyacrylate hollow microspheres were investigated and discussed. The mechanism for the formation of the polyacrylate hollow microspheres was proposed. This facile and scalable method for preparing hollow polymer microspheres is expected to be valuable to prepare various polymer hollow structures for widespread application.

A light stabilizer compound of 2‐(2′‐propionyloxy‐5′‐methylphenyl) benzotriazole (AMB) was synthesized by the esterification of the 2‐(2′‐hydroxy‐5′‐methylphenyl) benzotriazole with acryloyl chloride (AC), and the AMB was then copolymerized with the methyl methacrylate (MMA), butyl acrylate (BA), and silicone monomers (D4) to prepare the silicone light toughener of poly(D4‐MMA‐BA‐AMB). Effects of the AMB monomer on the conversion and polymerization stability and the toughening and photostabilizing effects of the poly(D4‐MMA‐BA‐AMB) on the polycarbonate (PC) were studied. The prepared multifunctional toughening agent was characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, thermogravimetric analyzer, transmission electron microscopy, dynamic light scattering analyzer, and ultraviolet absorption spectroscopy. Results show that the prepared poly(D4‐MMA‐BA‐AMB) toughening agent possessed core–shell structure and could effectively absorb the ultraviolet rays. Although the addition of the poly(D4‐MMA‐BA‐AMB) toughening agent had a negative effect on the tensile strength of the PC, it could greatly improve the low‐temperature notched impact strength, toughness performance, and yellowness performance of PC products after UV irradiation. Compared with the silicone toughening agent, the toughening agent of the poly(D4‐MMA‐BA‐AMB) had better anti‐ultraviolet property for the PC/poly(D4‐MMA‐BA‐AMB) composite. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48747.