scholarly journals Water-Resistant Latex Coatings: Tuning of Properties by Polymerizable Surfactant, Covalent Crosslinking and Nanostructured ZnO Additive

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 347
Author(s):  
Jana Machotová ◽  
Andréa Kalendová ◽  
Denisa Steinerová ◽  
Petra Mácová ◽  
Stanislav Šlang ◽  
...  

This paper deals with the development of acrylic latexes providing high-performance water-resistant coatings. For this purpose, mutual effects of anionic surfactant type (ordinary and polymerizable), covalent intra- and/or interparticle crosslinking (introduced by allyl methacrylate copolymerization and keto-hydrazide reaction, respectively) and ionic crosslinking (provided by nanostructured ZnO additive) were investigated. The latexes were prepared by the standard emulsion polymerization of methyl methacrylate, butyl acrylate and methacrylic acid as the main monomers. The addition of surface-untreated powdered nanostructured ZnO was performed during latex synthesis, resulting in stable latexes comprising dispersed nanosized additive in the content of ca 0.9-1.0 wt.% (based on solids). The coating performance with emphasis on water resistance was evaluated. It was determined that the application of the polymerizable surfactant improved coating adhesion and water-resistance, but it wasn′t able to ensure high water-resistance of coatings. Highly water-resistant coatings were obtained provided that covalent intra- and interparticle crosslinking together with ionic crosslinking were employed in the coating composition, forming densely crosslinked latex films. Moreover, coatings comprising nanostructured ZnO additive displayed a significant antibacterial activity and improved solvent resistance.

2021 ◽  
Vol 2021 ◽  
pp. 1-5
Author(s):  
Jianbing Lv ◽  
Juan Huang ◽  
Hao Wu ◽  
Yang Zhang ◽  
Jingyu Qiu ◽  
...  

Microsurfacing is a standard preventive maintenance technology developed on the basis of slurry sealing technology. However, the high temperature and rainy season in Guangdong Province affect its expanded application because of its low water resistance and short service life. So, high-performance microsurfacing, a new microsurfacing technology, has been developed. The key to this technique is an appropriate proportion of water-based epoxy resin and waterborne epoxy curing agent, which could generate a chemical reaction to form a high-performance bonding network structure of space. And indoor wet-wheel wear test shows that its antiwear ability and resistance to water damage are evidently increased (to over 50%) compared with the conventional microsurfacing. Furthermore, from the long-term road performance results, the antisliding and water resistance performance of high-performance microsurfacing is much higher than the conventional technique.


2021 ◽  
Vol 234 ◽  
pp. 117968
Author(s):  
Yuelan Li ◽  
Yan Yu ◽  
Xue Zhong ◽  
Youmiao Liu ◽  
Long Chen ◽  
...  

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 421
Author(s):  
Binwei Zheng ◽  
Weiwei Zhang ◽  
Litao Guan ◽  
Jin Gu ◽  
Dengyun Tu ◽  
...  

A high strength recycled newspaper (NP)/high density polyethylene (HDPE) laminated composite was developed using NP laminas as reinforcement and HDPE film as matrix. Herein, NP fiber was modified with stearic acid (SA) to enhance the water resistance of the NP laminas and NP/HDPE composite. The effects of heat treatment and SA concentration on the water resistance and tensile property of NP and composite samples were investigated. The chemical structure of the NP was characterized with X-ray diffractometer, X-ray photoelectron spectroscopy and attenuated total reflectance Fourier transform infrared spectra techniques. The surface and microstructure of the NP sheets were observed by scanning electron microscopy. An expected high-water resistance of NP sheets was achieved due to a chemical bonding that low surface energy SA were grafted onto the modified NP fibers. Results showed that the hydrophobicity of NP increased with increasing the stearic acid concentration. The water resistance of the composite laminates was depended on the hydrophobicity of the NP sheets. The lowest value of 2 h water absorption rate (3.3% ± 0.3%) and thickness swelling rate (2.2% ± 0.4%) of composite were obtained when the SA concentration was 0.15 M. In addition, the introduction of SA can not only enhance the water resistance of the composite laminates, but also reduce the loss of tensile strength in wet conditions, which shows potential in outdoor applications.


2017 ◽  
Vol 898 ◽  
pp. 2076-2080 ◽  
Author(s):  
Xing Qi Huang ◽  
Xiao Rong Li ◽  
Da Wei Zhang ◽  
Chang Jun Xue ◽  
Ai Qin Zhang

Compared with the traditional water reducer, polycarboxylicwater-reducing agent exhibits the advantages of high water-reducing rate, cement paste fluidity and low slump loss, etc. The structure of polycarboxylates water reducing agent molecular is comb type. Water reducing agent can be used in the molecular design because it has high water reducing rate, low dosage, good slump stability, and have great potential in increase strength. In recent years, it has attracted many researchers' attention. Water reducing agent can block or destroy cement granular flocculation structure, through the surface function, complexation, electrostatic repulsion force and stereo repulsive force. Research on water reducing agent based on the application of poly carboxylic acid can realize functional design of water reducing agent, so as to promote the development of high-performance concrete.


RSC Advances ◽  
2015 ◽  
Vol 5 (6) ◽  
pp. 4707-4715 ◽  
Author(s):  
Qiwei Zhang ◽  
Haiqin Sun ◽  
Tao Kuang ◽  
Ruiguang Xing ◽  
Xihong Hao

Materials emitting red light (∼611 nm) under excitation with blue light (440–470 nm) are highly desired for fabricating high-performance white light-emitting diodes (LEDs).


Author(s):  
Tatiyana V. Serebryanskaya ◽  
Alexander S. Lyakhov ◽  
Ludmila S. Ivashkevich ◽  
Yuri V. Grigoriev ◽  
Andreii S. Kritchenkov ◽  
...  

AbstractNovel platinum(II) and palladium(II) chlorido complexes with tetrazole derivatives 1-(2-hydroxyethyl)tetrazole (het) and 1-[tris(hydroxymethyl)methyl]tetrazole (thm), viz. cis-[Pt(het)2Cl2], trans-[Pt(het)2Cl2], trans-[Pt(thm)2Cl2], trans-[Pd(het)2Cl2], and trans-[Pd(thm)2Cl2], were synthesized. The compounds were characterized by elemental and high-resolution electrospray ionization (HRESI) mass spectrometry, high-performance liquid chromatography (HPLC), 1H, 13C and 195Pt nuclear magnetic resonance (NMR) spectroscopy, thermal analyses, and Infrared (IR) spectroscopy. Molecular and crystal structures of trans-[PdL2Cl2] and trans-[PtL2Cl2] (L = het, thm) were established by single-crystal X-ray analysis. The complex cis-[Pt(het)2Cl2] was found to undergo cis–to–trans isomerization upon heating in acetonitrile solution and in the solid state. The synthesized complexes show rather high water solubility lying in the range of 2–10 mg/L.


2015 ◽  
Vol 32 ◽  
pp. 113-127 ◽  
Author(s):  
Ji Wei Wu ◽  
Xin Feng Song ◽  
Han Wen Sun ◽  
Yan Cong Zhang ◽  
Xiang Ling Gu ◽  
...  

Chitosan is a kind of natural polymer commonly applied for nanomaterials, which is affluent in nature with favorable biodegradability and biocompatibility and free of toxicity or odor. In clinic it can be used as a drug carrier for the treatment of cancer, and also it is a kind of new pharmaceutical excipient. To prepare chitosan nanomaterial, various method are used, such as ionic crosslinking, covalent crosslinking, precipitation, free radical polymerization, reverse micelle, spray drying, and self-assembly. Furthermore, plenty of anti-tumor drugs, including adriamycin, epirubicin, taxol, 5-fluorouracil, norcantharidin, folic acid, and so on, are also attempted to load on these chitosan nanocarriers. In addition, the mechanism for those nanocarriers carrying anti-tumor drugs acting on tumor cell were explored, and the formulation mainly include electric charge adhesion effect, suppressing the proliferation of tumor cells, adjusting or enhancing immune ability of the body and inducing apoptosis. This paper compared the characteristics of different preparation methods on chitosan as a nanodrug carrier, summarized the types of packaged drugs, analyzed the mechanism of the chitosan as nanodrug carriers. It can provide valuable reference for researchers' further work.


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