Synthesis and characterization of fluoro-silicone polyacrylate latex emulsified with novel green surfactants

2018 ◽  
Vol 35 (2) ◽  
pp. 102-114
Author(s):  
Lijun Chen ◽  
Tantan Shao ◽  
Yilu Gong

The novel fluoro-silicone polyacrylate latex was successfully synthesized in the presence of a novel green mixed emulsifier of β-cyclodextrin ( β-CD) and sodium lauroyl glutamate (SLG) by semi-continuous seeded emulsion polymerization, which was initiated with potassium persulphate. Methyl methacrylate (MMA) and butyl acrylate (BA) were used as the main monomers, while hexafluorobutyl methacrylate (HFMA) and vinyltriethoxysilane (VTES) were used as the functional monomers. The resultant latex and its film were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry and contact angle determinator, respectively. The optimum conditions of preparing the fluoro-silicone polyacrylate latex are as follows: the amount of compound emulsifiers are 7.0%; β-CD: SLG = 1:2; the amount of initiator is 0.7%; the appropriate proportion of main monomer of MMA: BA = 1:1; and the amounts of HFMA and VTES are 6.0% and 4.0%, respectively. In this case, the resultant latex has high conversion rate, low gel rate and good stability. Results showed that both thermal stability and hydrophobic property of the latex are improved with the incorporation of a small amount of HFMA and VTES.

2018 ◽  
Vol 9 (3-4) ◽  
pp. 145-151 ◽  
Author(s):  
Lijun Chen ◽  
Tantan Shao ◽  
Xin Zhang ◽  
Xiuming Wang ◽  
Dawei Chen

The polyacrylate latex has been successfully prepared by semicontinuous seeded emulsion polymerization with methyl methacrylate (MMA), butyl acrylate (BA), and acrylic acid (AA), which were initiated with potassium persulfate and emulsified with the novel green mixed surfactants of alkyl polyglycoside (APG1214) and disodium laureth sulfosuccinate (MES). The particle size of the latex was measured by Zetatrac dynamic light scattering detector. The structure of the latex was tested by Fourier-transform infrared spectroscopy. The film of latex was tested by differential scanning calorimetry and thermogravimetric analysis. Factors, which had an influence on the properties of the latex, were studied in detail. The optimum conditions for preparing the polyacrylate latex were as follows: the amount of emulsifiers was 7.0%, the mass ratio of APG1214 to MES was 3:1, the amount of the initiator was 0.7%, the mass ratio of MMA to BA was 1:1, and the amount of AA was 2.0%. In this case, the conversion of the mixed monomers was high and the mechanical and ionic stability of the latex was good.


2013 ◽  
Vol 17 (06n07) ◽  
pp. 573-586 ◽  
Author(s):  
Çiğdem Yağcı ◽  
Ahmet Bilgin

A phthalonitrile precursor 4-(3-hydroxypropylmercapto)phthalonitrile (3) was synthesized via a base-catalyzed nucleophilic aromatic nitro displacement of 4-nitrophthalonitrile with the 3-mercapto-1-propanol. A novel tetrasubstituted metal-free phthalocyanine (4) ( M = 2 H ) and its metal complexes (5–8) ( M = Zn , Ni , Cu and Co ) bearing 3-hydroxypropylmercapto moieties were prepared by the cyclotetramerization reaction of (3) with the appropriate materials. The visible spectra of the zinc(II) phthalocyanine (5) was recorded with different concentrations and different ions as Ag +, Hg 2+ and Pb 2+ in DMF and also with different solvents as dimethylformamide and pyridine. Fluorescence spectrum of the compound (5) was also studied. Temperature and frequency dependence of AC conductivity for (4–8) was investigated in air and under vacuum and were found to be ~10-8–10-5 S.m-1. Thermal properties of the phthalocyanines were examined by differential scanning calorimetry. All the novel compounds have been characterized by elemental analysis, UV-vis, FT-IR, NMR and MS spectral data and DSC techniques.


Coatings ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 936 ◽  
Author(s):  
Ting Liu ◽  
Jingfan Wang ◽  
Fumin Chi ◽  
Zhankun Tan ◽  
Liu Liu

The effects of fennel essential oil (FEO) and peppermint essential oil (PEO) on chitosan-based films were evaluated in this study. The results showed that the addition of FEO and PEO slightly increased the density and thickness, while significantly decreasing the moisture content, water swelling, and solubility properties. The color values (L, a, b, ΔE and whiteness index (WI)) of the composite films containing FEO and PEO changed obviously with a tendency toward yellowness, which was beneficial in resisting food decomposition caused by ultraviolet light. The differential scanning calorimetry (DSC) and fourier-transform-infrared (FTIR) results indicated that the addition of FEO and PEO affected the structure of the chitosan films, while the interaction between the chitosan and polyphenols in FEO and PEO established new hydrogen bonds and improved the thermal stability. The environmental scanning electron microscopy (ESEM) illustrated that the surfaces of the composite films containing FEO and PEO were smooth, but the cross-section was rougher than in pure chitosan film. Furthermore, the composite films containing FEO and PEO exhibited prominent antioxidant activity. In short, the novel active chitosan-based films with incorporated FEO and PEO present broad application prospects in fresh-cut meat or vegetable packaging.


2012 ◽  
Vol 725 ◽  
pp. 277-280 ◽  
Author(s):  
Koichiro Inaba ◽  
Yujin Takemoto ◽  
Kouji Toyota ◽  
Kenichi Haga ◽  
Kouichi Tokudome ◽  
...  

A novel precursor for ZnO film deposition with Zn-O structure was synthesized by the reaction of diethylzinc and water in some ether solvents. The novel precursor was characterized by 1H-NMR spectroscopy and differential scanning calorimetry (DSC). Nondoped and In-doped ZnO films on a glass substrate have been successfully grown by conventional spin coating using nondoped and In added novel precursor solution. The samples have an optical transmittance of more than 85%, and a smooth surface determined from optical transmittance and scanning electron microscopy, respectively. The sheet resistivity of In-doped ZnO films is lower than that of nondoped ZnO film.


2010 ◽  
Vol 123-125 ◽  
pp. 387-390 ◽  
Author(s):  
C.V. Prasad ◽  
K.M. Sudhan Rao ◽  
B. Mallikarjuna ◽  
M.C.S. Subha ◽  
K. Chowdoji Rao

Methacrylic acid (MAA) was grafted onto sodium alginate (SA) by thermal heating at ambient temperature (70±2OC) using potassium persulphate as an initiator (PPS). SA-g-MAA and pure sodium alginate beads were prepared and were characterized using Scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and X-ray diffraction techniques (X-Rd). The resultant products (SA-g-MAA) were used to prepare Glutaraldehyde (GA) crosslinked beads of various formulations by varying, monomer, cross-linker (GA) and drug content (CFHCl) in the graft co-polymer. Preparation conditions of the beads were optimized by considering the percentage entrapment efficiency, swelling capacity and release profiles. Release profile of CFHCl was discussed at 370C in a gastrointestinal atmosphere (pH -7.4 and acidic medium pH-1.2). It was observed that, CFHCl release from the beads increased with increasing MAA content over the entire studied range. As GA and CFHCl content increases, swelling ratio decreases resulting in decrease in the drug release rate. The highest CFHCl release was obtained to be 99% for the beads containing 40% monomer, 0.5mL GA and 10% CFHCl at pH-7.4. It was also observed that the release profiles have effect on pH and hence the graft co-polymeric beads can be used as pH sensitive drug devices.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Tantan Shao ◽  
Xiaolong Chen ◽  
Lijun Chen

Purpose Silane cross-linkers have been used to strengthen the mechanical stabilities and friction resistance of plastic products. Therefore, the effect of silane cross-linkers on latex has been studied through preparing modified self-cross-linking long fluorocarbon polyacrylate latex. In this paper, nonionic surfactant alcohol ether glycoside (AEG1000) and anionic polymerizable surfactant 1-allyloxy-3-(4-nonylphenol)-2-propanol polyoxyethylene (10) ether ammonium sulfate (DNS-86) acted as mixed emulsifier and 3-(methacryloyloxy) propyltrimethoxysilane (KH-570) and bis (2-ethylhexyl) maleate (DOM) were used as functional monomers. Design/methodology/approach The modified acrylate polymer latex was synthesized through the semi-continuous seeded emulsion polymerization with methyl methacrylate (MMA), butyl acrylate (BA), dodecafluoroheptyl methacrylate (DFMA) and hydroxypropyl methacrylate (HPMA) as main monomers. Potassium persulfate (KPS) was applied to initiate polymerization reaction, nonionic surfactant AEG1000 and DNS-86 acted as emulsifier, KH-570 and DOM were used as functional monomers, respectively. Findings The optimum conditions of synthesizing the modified latex were the following. The mass ratio of monomers containing MMA, BA, DFMA, HPMA, KH-570 and DOM was 13.58:13.58:0.90:1.20:0.15:0.60, the usage of initiator KPS was 0.5% of the total weight of monomers and the amount of emulsifier was 7% of all monomers with AEG1000:DNS-86 = 1:1. The results indicated that the conversion of monomer was 99% and the coagulation was about 2.0%. Originality/value The resultant latex was modified silane cross-linker KH-570 and DOM, which positively affected the comprehensive properties of latex and its film. Apart from this, the novel mixed emulsifier was used to improve the size and distribution of latex particles and reduce environmental problems caused by the use of emulsifiers.


2019 ◽  
Vol 35 (4) ◽  
pp. 188-197
Author(s):  
Lijun Chen ◽  
Tantan Shao ◽  
Yilu Gong ◽  
Xiuming Wang

The novel vinyl acetate (VAc)/vinyl neo-decanoate (VeoVa10)/dibutyl maleate/triethoxy vinyl silane quadripolymer latex was prepared via the semi-continuous seeded emulsion polymerization emulsified with disodium laureth sulfosuccinate (AEMES) as anionic surfactant and beta-cyclodextrin (β-CD) mixture as emulsifier and initiated with potassium persulfate (KPS), respectively. The chemical compositions of copolymer was determined by Fourier transform infrared spectromer (FTIR). The glass transition temperature ( Tg) of the copolymer was measured by differential scanning calorimetry. The water resistance of the film was assessed by the water contact angle measurement. The conditions of preparing the novel latex were optimized and obtained as follows. The amount of AEMES and β-CD mixtures were 6 wt% and the mass ratio of AEMES to β-CD were 1:1. The dosage of KPS was 0.6 wt% and the mass ratio of VAc to VeoVa10 was 3:1. The amount of dibutyl maleate and triethoxy vinyl silane was 4% and 3%, respectively. In this case, the conversion percentage of the mixed monomers was 99.0% and the polymerization stability was good.


Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1464 ◽  
Author(s):  
Ugochukwu C. Okeke ◽  
Chad R. Snyder ◽  
Stanislav A. Frukhtbeyn

Methacrylate analogs of quaternary ammonium salts functionalized with carboxylic (AMadh1 68.8% yield, AMadh2 53.2% yield) and methoxysilane (AMsil1 94.8% yield, AMsil2 36.0% yield) groups were synthesized via Menschutkin reaction. Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (1H, 13C and 2D 1H-13C heteronuclear single quantum coherence (HSQC) NMR), mass spectrometry, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were utilized to validate structures and characterize thermal properties of the novel multifunctional quaternary ammonium salts synthesized. The potential adhesive, coupling and antimicrobial properties of these multifunctional monomers encourage their further comprehensive evaluation in conventional and experimental copolymers and composites.


Author(s):  
B. M. Culbertson ◽  
M. L. Devinev ◽  
E. C. Kao

The service performance of current dental composite materials, such as anterior and posterior restoratives and/or veneer cements, needs to be improved. As part of a comprehensive effort to find ways to improve such materials, we have launched a broad spectrum study of the physicochemical and mechanical properties of photopolymerizable or visible light cured (VLC) dental composites. The commercially available VLC materials being studied are shown in Table 1. A generic or neat resin VLC system is also being characterized by SEM and TEM, to more fully understand formulation variables and their effects on properties.At a recent dental research meeting, we reported on the differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) characterization of the materials in Table 1. It was shown by DSC and DMA that the materials are substantially undercured by commonly used VLC techniques. Post curing in an oral cavity or a dry environment at 37 to 50°C for 7 or more hours substantially enhances the cure of the materials.


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