The results of spectrophotometry and TEM revealed that materials with a higher homogeneity degree of morphological structure could obtain 98.7% of transmittance at a wavelength of 680 nm.

A fluorine-containing methylacrylate copolymer latex has been synthesized by emulsion polymerization and was used as a water- and oil-repellent agent to treat some pure cotton woven fabrics at different dry and curing temperature. The treated cotton fabric surfaces were investigated by attenuated total reflectance infrared analysis and angle-dependent X-ray photoelectron spectroscopy directly. The analysis results could agree with the fluorine-containing copolymer real situation on the fabrics surface much more, and could indicate, factually, surface properties of treated or modified material rather than copolymer film. It was found that fluorine elements are enriched at the air-polymer interface and fluorine content of the treated cotton fabrics surface decreases with increasing analysis depth, which depends on heating and cooling experience, such as annealing and quenching. Furthermore, the results showed that almost the same effect can be attained using this copolymer curing from 100°C to 175°C; the relatively low curing temperature is very valuable and advantageous for some fabrics which would yellow easily at higher temperatures. The water- and oil-repellency grade of treated cotton fabrics by the fluorine-containing methylacrylate copolymer latex increases with an increase on fluorine content on the surface.

A facile route was introduced to prepare homogeneous silicone resin doped with titanium hybrid with high refractive index (RI). Specifically, the hybrids were obtained from the transesterification of hydroxyl‐phenyl‐vinyl silicone resin and titanium isopropoxide under anhydrous conditions. The structures of hybrid silicone and their corresponding intermediates (hydroxyl‐phenyl‐vinyl silicone) were characterized by nuclear magnetic resonance spectroscopy (1H NMR, 29Si NMR) as well as Fourier transform infrared spectroscopy (FTIR). The hybrids had a transmittance of more than 88% ranging from 450 nm to 800 nm, a high RI of 1.585, and a lower water vapor permeability of 3.58 g /m2.24h. Results from FTIR showed intensity of Ti‐O‐Si bond in hybrid decrease with extended the storage time, but the properties of cured hybrids including optical, mechanical, and gas permeability were not influenced. Compared to chips encapsulated with pure silicone, the luminous efficiency of the chips encapsulated with hybrids was improved from 138.6 lm/W to 156.4 lm/W. The thermal shock and hygrothermal aging test also demonstrated the hybrids had a wide range application in light‐emitting diode (LED) packaging. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47834.

Fluorosilane-grafted iron oxide (F-Fe2O3) was prepared via surface grafting reaction between iron oxide and perfluorooctyltriethoxysilane. The effect of F-Fe2O3 on the tracking resistance (TR) of addition-cured liquid silicone rubber (ALSR) was investigated by the inclined-plane test (IPT), surface potential decay test (SPDT), thermogravimetry (TGA), corona aging test and scanning electron microscopy (SEM). F-Fe2O3 delayed the occurrence of the intensive arc discharge and reduced the number of arc discharges. The corona resistance and TR of ALSR were effectively improved. ALSR/F-Fe2O3 with 0.15 phr F-Fe2O3 content passed the IPT at 4.5 kV, showing an erosion mass of 3.17%. The hydrophobicity and thermal stability of ALSR were also enhanced. The SPDT showed that F-Fe2O3 effectively dissipated charge. The results of thermal stability and corona resistance tests revealed that F-Fe2O3 could capture free radicals generated by the oxidation of methyl side groups of ALSR chains and thus inhibit the thermal degradation of ALSR during the arc discharge. Moreover, the charge dissipation by F-Fe2O3 could diminish the accumulation of charges in ALSR and reduce the damage of charges to the chains during arc discharge. Therefore, the TR of ALSR was enhanced.

No abstract