Preparation and characterisation of novel cross-linked poly (IBOMA-BA-DFMA) latex

Purpose – The purpose of this research was to synthesize a novel cross-linked latex copolymerised by butyl acrylate (BA), isobornyl methacrylate (IBOMA), hydroxy propyl methacrylate (HPMA) and dodecafluoroheptyl methacrylate (DFMA). IBOMA is a very useful functional monomer. Its molecular structure not only contains bornyl acetate alkoxy but also includes a double bond, which can be copolymerised with other unsaturated monomers via free radical polymerization. The large nonpolar bicyclic alkyl in bornyl acetate alkoxy offers the polymer chain strong space steric protection, which endows the polymer with some special properties. Design/methodology/approach – The semi-continuous seeded emulsion polymerisation technology was adopted to copolymerise BA, IBOMA, HPMA and DFMA in the water phase, which was initiated with potassium persulfate (KPS) and emulsified with the mixed surfactants of sodium dodecyl sulphate (SDS) and OP-10. Findings – The particle size of the latex decreases with an increase in the amount of IBOMA. All the latexes have good mechanical stability and calcium ion stability. The latex has good film-forming property when the IBOMA amount is controlled moderately. The optimal IBOMA amount is 10.00 g. The thermal stability and water resistance of the film are improved. Practical implications – The latexes can be applied as a binder of coatings and adhesions. Originality/value – The effect of the amount of IBOMA and BA on the properties of the resultant latex and its film were investigated in detail. In comparison with the latexes copolymerised without IBOMA, the novel latex has better thermal stability and water resistance.

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Synthesis and characterization of non-ionic and anionic two-component aromatic waterborne polyurethane

Pigment & Resin Technology ◽

10.1108/prt-07-2017-0067 ◽

2018 ◽

Vol 47 (4) ◽

pp. 290-299 ◽

Cited By ~ 3

Author(s):

Sainan Zhang ◽

Xiankai Jiang

Keyword(s):

Thermal Stability ◽

Water Resistance ◽

Soft Segment ◽

Aqueous Dispersion ◽

Waterborne Polyurethane ◽

Content Type ◽

Hydrophilic Modification ◽

Two Component ◽

Better Than

Purpose The purpose of this paper is to synthesize and characterize a series of two-component aromatic waterborne polyurethane (2K-WPU) which is composed of non-ionic and anionic polyisocyanate aqueous dispersion and polyurethane polyol aqueous dispersion. Design/methodology/approach The polyisocyanate aqueous dispersion was synthesized through non-ionic and anionic hydrophilic modification procedures. The values of the hydrogen bonding index (HBI) and molecule structures of WPU were obtained by Fourier transform infrared (FTIR). The thermal, mechanical and water resistance properties of 2K-WPU films were investigated. Findings The appearance of non-ionic polyisocyanate aqueous dispersion and anionic polyisocyanate aqueous dispersion was colorless translucent pan blue and yellow opaque emulsions, respectively. FTIR not only showed that 2K-WPU was obtained from the polymerization of polyisocyanate component and polyhydroxy component by polymerization but also showed that the content of hydrogen bondings of anionic 2K-WPU (WPU 2) was higher than non-ionic 2K-WPU (WPU 1). The glass-transition temperature (Tg), storage modulus and water resistance of WPU 2 were higher than WPU1, whereas the thermal stability of WPU1 was better than WPU 2. Practical implications The investigation established a method to prepare a series of 2K-WPU which was composed of non-ionic or anionic polyisocyanate aqueous dispersion and polyurethane polyol aqueous dispersion. The prepared 2K-WPU film could be applied as substrate resin material in the field of waterborne coating. Originality/value The paper established a method to synthesize a series of 2K-WPU. The effect of HBI value and the molecule structure of soft segment on the thermal stability, mechanical and water resistance properties of 2K-WPU films were studied.

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Effect of preparation process on elevated temperature tribological properties of composite polyurea grease

Industrial Lubrication and Tribology ◽

10.1108/ilt-12-2015-0199 ◽

2016 ◽

Vol 68 (5) ◽

pp. 611-616 ◽

Cited By ~ 3

Author(s):

Zujian Shen ◽

Fei Geng ◽

Xinxin Fan ◽

Zhichen Shen ◽

Haiyan Wang

Keyword(s):

Thermal Stability ◽

Elevated Temperature ◽

Tribological Properties ◽

Water Resistance ◽

Physical Method ◽

Heat Stability ◽

Wear Properties ◽

Excellent Thermal Stability ◽

Content Type ◽

Polyurea Grease

Purpose This paper aims to investigate and prepare the composite polyurea greases with excellent thermal stability and tribological properties. Design/methodology/approach In this paper, composite Ba-based (Ba, barium) tetra-polyurea lubricating greases were prepared with two different methods: mixing Ba-based gelatinizer and tetra-polyurea gelatinizer by a physical method; and introducing barium carboxylate into tetra-polyurea molecules by a chemical method. The properties of the products, such as heat stability, water resistance and friction performance, were analyzed with thermogravimetry, water-resistance test and four-ball friction test. Findings The results indicated that the products obtained by chemically introducing barium carboxylate into tetra-urea molecules showed better elevated temperature tribological properties, and the disadvantages of the polyurea greases with high temperature hardening were also obviously improved. The cone penetration rate at 180°C for 24 h is only 3 per cent. The friction coefficient can be decreased to 0.44 and the last non-seizure load value was increased from 560 N to 1,120 N without any other additives. Originality/value The research is significant because the prepared composite grease showed excellent performances, such as the outstanding thermal stability, water resistance and excellent extreme pressure and anti-wear properties, which may be widely applied in steel, metallurgy, bearings and other industrial fields.

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Synthesis and properties of novel self-crosslinked cationic fluorinated acrylic latex prepared with novel emulsified system

Pigment & Resin Technology ◽

10.1108/prt-07-2015-0061 ◽

2016 ◽

Vol 45 (4) ◽

pp. 259-264

Author(s):

Wen Li ◽

Zhongbin Bao ◽

Lijun Chen ◽

Dongshun Deng

Keyword(s):

Particle Size ◽

Gemini Surfactants ◽

Average Particle Size ◽

Water Soluble ◽

Average Particle ◽

Mixed Surfactants ◽

The Novel ◽

Content Type ◽

Acrylic Latex ◽

Emulsion Polymerisation

Purpose At present, the conventional method of preparing cationic fluorinated acrylic latex is to emulsify copolymerised monomers with cationic surfactants. However, there has been a wide concern about using Gemini surfactants to prepare cationic polymer latex to improve its properties. The purpose of this paper was to focus on the synthesis of novel self-crosslinked cationic fluorinated acrylic latex (SCFAL), during which the copolymerised monomers were initiated with a water soluble azo initiator and emulsified with mixed surfactants of Gemini emulsifier and alkyl polyglycoside (APG). Design/methodology/approach The novel SCFAL was prepared successfully by the semi-continuous seeded emulsion polymerisation of butyl acrylate, methyl methacrylate, hexafluorobutyl methacrylate (HFMA) and hydroxy propyl methacrylate (HPMA) in aqueous medium. Findings The conversion is the maximum and the coagulation percentage the minimum when the amounts of emulsifier and initiator are 8 and 0.6 per cent, respectively. The average particle size of the latex is significantly reduced with the increase of the amount of emulsifiers used. However, the average particle size of the latex is increased with the increase of the amount of HPMA. The particle size of the latex is of a unimodal distribution, which means that the particle size was reasonably uniform. Contact angle is increased with the increase of the amount of the HFMA. Practical implications The novel SCFAL can be widely used as significant components in the field of coatings, leather, textile, paper, adhesives and so on. Originality/value SCFAL, which was emulsified with novel mixed surfactants of Gemini surfactant and APG, has been prepared successfully. Influences of amount of initiator, emulsifier, HPMA and HFMA on emulsion polymerisation and/or properties of novel latex are investigated in detail.

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Synthesis and characterisation of fluorine-silicon acrylate latex emulsified by novel green surfactants

Pigment & Resin Technology ◽

10.1108/prt-03-2017-0025 ◽

2018 ◽

Vol 47 (3) ◽

pp. 255-260 ◽

Cited By ~ 1

Author(s):

Lijun Chen ◽

Xin Zhang ◽

Cuifeng Zhang ◽

Zhongbin Bao ◽

Tingting Xu

Keyword(s):

Water Resistance ◽

Mixed Surfactants ◽

Mass Ratio ◽

Acrylic Copolymer ◽

Content Type ◽

Acrylate Copolymer ◽

Emulsion Polymerisation ◽

Alkyl Polyglycoside ◽

Acrylate Latex ◽

Practical Implications

Purpose Motivated by the globally increasing concern over environmental protection, the interest of a large part of the scientific community focuses on the development of green surfactants aiming to replace traditional toxic surfactants-based alternatives. The purpose of this paper is to prepare acrylate copolymer latex modified with fluorine and silicone monomer, which is emulsified with the green surfactants of sodium rosinate and alkyl polyglycoside (APG). Design/methodology/approach A series of acrylic copolymer latexes containing fluorine–silicon have been prepared by semi-continuous seed emulsion polymerisation of mixed monomers of methyl methacrylate (MMA), butyl acrylate (BA), hexafluorobutylmethacrylate (HFMA) and vinyltriethoxysilane (VTES) and emulsified by green mixed surfactants of sodium rosinate and APG. Findings The optimum recipe of preparing the emulsion is as follows: the amount of emulsifiers is 6 per cent and the mass ratio of sodium rosinate to APG is 1:3. The amount of initiator is 0.4 per cent, and the amounts of the silicon monomer and fluorine monomer are 5 and 7 per cent, respectively. In comparison with the acrylate latex prepared without fluorine monomer and silicon monomer, the thermal stability and the water resistance of the film of the resultant latex clearly improved. Practical implications The acrylic copolymer latexes containing fluorine–silicon emulsified with green surfactants can be used in the coatings, adhesives, finishing agents and so on. Originality/value The acrylic copolymer latexes containing fluorine–silicon have been prepared by semi-continuous seed emulsion polymerisation. The green mixed surfactants of sodium rosinate and APG have been used as the emulsifiers to replace traditional toxic surfactants-based alternatives.

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Synthesis and characterization of alicyclic two-component waterborne polyurethane

Pigment & Resin Technology ◽

10.1108/prt-07-2017-0064 ◽

2018 ◽

Vol 47 (4) ◽

pp. 315-322 ◽

Cited By ~ 1

Author(s):

Jizhi Zhang ◽

Xiankai Jiang

Keyword(s):

Thermal Stability ◽

Water Resistance ◽

Aqueous Dispersion ◽

Waterborne Polyurethane ◽

Molar Ratio ◽

Mechanical And Thermal Properties ◽

Content Type ◽

Two Component ◽

Practical Implications

Purpose The purpose of this paper is to synthesize and characterize a series of alicyclic two-component waterborne polyurethane (2K-WPU) which is composed of non-ionic polyisocyanate aqueous dispersion and hydroxyl aqueous dispersion. Design/methodology/approach The appearances of aqueous dispersions and 2K-WPU films were observed by photographs. The micromorphology of alicyclic polyisocyanate aqueous dispersion was examined by scanning electron microscopy (SEM). The molecule structures of WPU were studied by Fourier transform infrared (FTIR). The effect of NCO:OH molar ratio of two components and trimethylolpropane (TMP) content on the thermal stability, mechanical and water resistance properties of 2K-WPU films was studied. Findings It was found by SEM that alicyclic polyisocyanate particles in aqueous dispersion showed a kind of spherical particle appearance, in which hydrophobic polyisocyanate was encapsulated by hydrophilic ether linkages segment. FTIR showed that WPU was polymerized through mixture of polyisocyanate component and hydroxyl component and increasing NCO:OH molar ratio of two components from 1.1:1 to 1.5:1 had increased the content of urea, urethane and allophanate of 2K-WPU films. Increasing NCO:OH molar ratio had improved the mechanical and thermal properties of the 2K-WPU film, but the water resistance of the 2K-WPU film increased first and then weakened. Increasing TMP contents from 1 to 0.75 mol for 1:5 system had improved the mechanical, thermal and water resistance properties of the 2K-WPU film. Practical implications The investigation established a method to prepare alicyclic 2K-WPU which is composed of non-ionic polyisocyanate aqueous dispersion and hydroxyl aqueous dispersion. The prepared 2K-WPU film could be applied in the field of waterborne surface coating, e.g. textile, wood and synthetic leather surfaces (Hasan et al., 2017; Akindoyo et al., 2016). Originality/value The paper established a method to synthesize alicyclic two-component 2K-WPU. The effect of NCO:OH molar ratio and TMP content on the thermal stability, mechanical and water resistance properties of 2K-WPU films were studied.

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Preparation and characterisation of modified VAc-VeoVa10 latex

Pigment & Resin Technology ◽

10.1108/prt-05-2018-0045 ◽

2019 ◽

Vol 48 (3) ◽

pp. 210-215 ◽

Cited By ~ 1

Author(s):

Yilu Gong ◽

Tantan Shao ◽

Xiuming Wang ◽

Xin Zhang ◽

Zhijuan Sun ◽

...

Keyword(s):

Vinyl Ester ◽

Water Repellency ◽

Latex Film ◽

Mixed Surfactants ◽

The Novel ◽

Mass Ratio ◽

Optimum Conditions ◽

Content Type ◽

Emulsion Polymerisation ◽

Silicon Materials

Purpose Fluorine and silicon materials have received the keen attention of many researchers because of their water repellency and low surface free energy. The purpose this study was to prepare vinyl acetate (VAc)-vinyl ester of neodecanoic acid (VeoVa 10) copolymer latex modified with fluorine and silicone monomer, which is emulsified with the novel surfactants of disodium laureth sulfosuccinate (MES) and octylphenol polyoxyethylene ether (OP-10). Design/methodology/approach A series of modified latices containing fluorine-silicon have been prepared by semi-continuous seeded emulsion polymerisation of mixed monomers of VAc, VeoVa10, hexafluorobutylmethacrylate (HFMA) and vinyltriethoxysilane (VTES) and emulsified by novel surfactants of MES and OP-10. Findings The optimum conditions for preparing the modified latex is as follows: the amount of the surfactant was 4.0 Wt.% and the mass ratio of the anionic and nonionic surfactant was 3:1; the dosage of initiator was 0.4 Wt.% and the mass ratio of the main monomer was 3:1; and the amounts of VTES and HFMA were 2.0 and 6.0 Wt.%, respectively. In comparison with the conventional latex, the hydrophobicity of latex film was improved further. Originality/value The modified p (VAC-VeoVa) latex is prepared via semi-continuous seeded emulsion polymerisation, which is emulsified with the novel mixed surfactants of MES and OP-10. There are two main innovations. One is that the novel p (VAC-VeoVa) latex containing fluorine-silicon is prepared successfully. The other is that the emulsifier is composed of the novel mixed surfactants of MES and OP-10.

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New water-based copolymer nanoparticles and their use as eco-friendly binders for industry of flexographic ink, part I

Pigment & Resin Technology ◽

10.1108/prt-10-2019-0095 ◽

2020 ◽

Vol 49 (3) ◽

pp. 239-248

Author(s):

H. Abd El-Wahab ◽

G. El-Meligi ◽

M.G. Hassaan ◽

A. Kazlauciunas ◽

Long Lin

Keyword(s):

Water Resistance ◽

Gel Permeation Chromatography ◽

Adhesion Properties ◽

Content Type ◽

Low Viscosity ◽

Base Paper ◽

Transmission Electron ◽

Emulsion Polymerisation ◽

Water Based ◽

Excellent Adhesion

Purpose The purpose of this paper is to prepare, characterise and evaluate nano-emulsions of copolymers of various compositions as eco-friendly binders for flexographic ink industry. Design/methodology/approach Various nano-emulsions of copolymers were prepared using styrene (St), butyl acrylate (BuAc), acrylic acid (AA) and acrylamide (AAm) monomers by means of a conventional seeded emulsion polymerisation technique, using K2S2O8 as the initiator. The characterisation of the prepared emulsions was performed using Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), gel permeation chromatography (GPC) and transmission electron microscopy (TEM). A selection of copolymers was formulated with pigments and additional ingredients, as water-based flexographic inks. The inks were characterised for their viscosity, pH, degree of dispersion, water resistance and colour density. Findings It was found that the low viscosity of the prepared copolymers may reduce the film thickness of the flexographic inks and may also increase the spreading of the ink on the surface. As a result, stable modified polyacrylate-based latex with improved physico-mechanical properties were obtained. The prepared latexes were showed improving and enhancing in water resistance; gloss values, and the print density that ranged from 2.06 to 2.51 and the maximum gloss values (39 and 48) were also obtained. Also, these binders provide excellent adhesion properties for both the pigment particles and the base paper. Practical implications This study focuses on the preparation of new water-based copolymer nanoparticles and their use as eco-friendly binders for flexographic ink industry. Social implications The ink formulations developed could find use in industrial-scale printing. Originality/value Eco-friendly environment ink formulations for printing on paper substrates are novel.

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XYLANASE, AN ENVIRONMENTALLY FRIENDLY BLEACHING AGENT FOR PULP AND PAPER: Characterization And Stabilization Study Of Bacillus licheniformis I-5 CRUDE Xylanase

Jurnal Rekayasa Lingkungan ◽

10.29122/jrl.v7i3.1961 ◽

2018 ◽

Vol 7 (3) ◽

Author(s):

Budiasih Wahyuntari., dkk

Keyword(s):

Thermal Stability ◽

Bacillus Licheniformis ◽

Hot Spring ◽

Sodium Dodecyl ◽

Luria Broth ◽

Crude Enzyme ◽

Half Time ◽

Triton X100 ◽

Sds Page ◽

Xylanolytic Enzymes

Isolate I-5 was isolated from Ciseeng hot spring, West Java and was identified as Bacillus licheniformis I-5. The isolate produces extracellular xylanolytic enzymes on Oatspelt containing Luria broth agar medium. Optimal activity of the crude enzyme was Â observed at 50ÂºC and pH 7. The effect of sodium dodecyl sulphate, b-mercaptoethanol and Triton-X100 were observed. Incubating the crude enzyme in 1.5% SDS and 1.5% b-mercaptoethanol at 50oC for 90 minutes then adding Triton-X100 at final concentration of 3.5% for 45 minutes only reduced 5.75% of the initial enzyme activity. SDS/PAGE and zymogram analysis showed that at least two xylanolytic enzymes presence in the crude enzyme. The molecular weight of the enzyme was estimated about 127 and 20kD. The enzyme hydrolysed xylan into xylobiose, xylotriose and other longer xylooligosaccharides. Thermal stability of the crude enzyme was observed at 50, 60, and 70oC and pH 7 and 8. The results showed that the half time of the crude enzyme incubated at 50, 60, and 70oC pH 7 was 2 hours 55 minutes; 2 hours 33 minutes and 1 hour 15 minutes respectively. The half time at 50, 60 and 70oC, pH 8 was 2 hours 48 minutes; 1 hour 22 minutes and 1 hour 9 minutes respectively.keywords: Xilanase, Bacillus licheniformis I-5, thermal stability

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Mechanical Stability of Hybrid Corrugated Sandwich Plates under Fluid-Structure-Thermal Coupling for Novel Thermal Protection Systems

Applied Sciences ◽

10.3390/app10082790 ◽

2020 ◽

Vol 10 (8) ◽

pp. 2790

Author(s):

Wenzheng Zhuang ◽

Chao Yang ◽

Zhigang Wu

Keyword(s):

Mechanical Stability ◽

Thermal Protection ◽

Element Model ◽

Parameter Study ◽

The Novel ◽

Thermal Coupling ◽

Mechanical Instability ◽

Fluid Structure ◽

Thermal Protection Systems ◽

Protection Systems

Hybrid corrugated sandwich (HCS) plates have become a promising candidate for novel thermal protection systems (TPS) due to their multi-functionality of load bearing and thermal protection. For hypersonic vehicles, the novel TPS that performs some structural functions is a potential method of saving weight, which is significant in reducing expensive design/manufacture cost. Considering the novel TPS exposed to severe thermal and aerodynamic environments, the mechanical stability of the HCS plates under fluid-structure-thermal coupling is crucial for preliminary design of the TPS. In this paper, an innovative layerwise finite element model of the HCS plates is presented, and coupled fluid-structure-thermal analysis is performed with a parameter study. The proposed method is validated to be accurate and efficient against commercial software simulation. Results have shown that the mechanical instability of the HCS plates can be induced by fluid-structure coupling and further accelerated by thermal effect. The influences of geometric parameters on thermal buckling and dynamic stability present opposite tendencies, indicating a tradeoff is required for the TPS design. The present analytical model and numerical results provide design guidance in the practical application of the novel TPS.

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