JOURNAL OF ELASTOMERS AND PLASTICS
·
2023
·
IF 1.7
Zheqing Gong,Lijun Chen
Modified latex is prepared via the soap-free emulsion polymerization of ethyl acetate (VAc) and vinyl versatate (VeoVa10). DFHMA is used as modified monomers. The composite surfactants of SR-10 and ANPEO-10 are used as the composite emulsifiers. The polymerization is initiated by potassium sulfate (KPS). The structure of latex film was characterized by Fourier transform infrared spectroscopy (FTIR). The latex films were tested by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and contact angle (CA) determinator. The particle size of the latex emulsion particle size is determined by the Zetatrac dynamic light scatter. Results show that the optimum condition of preparing the modified latex can be obtained, i.e. the amount of emulsifier is 4.0%; the mass ratio of SR-10 to ANPEO-10 is 1:1; the amount of initiator is 0.5%; the mass ratio ofVAc to VeoVa10 is 1:1; the amount of DFHMA is 5.0%. The appearance of the latex is blue and translucent with a small particle size. The conversion rate is more than 98%. Compared with the conventional latex, the hydrophobicity and heat resistance of the film have been improved. Moreover, the latex has good chemical stability and mechanical stability.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
Pigment & Resin Technology
·
2024
·
IF 1.3
Lijun Chen,Wanting Zhao,Zheqing Gong
PurposeThe traditional vinyl ester of neodecanoic acid-vinyl acetate (VeoVa10-VAc) copolymer latex is a linear structure with poor film formation, thus causing solvent resistance and wear resistance of the latex film to be poor. This study aims to investigate the use of cross-linkers in emulsion polymerization to modify the latex. During the course of film formation, the reactive functional groups react to form cross-linkage. The network structure can effectively improve the compactness of the resin, thereby greatly improving the water resistance, solvent resistance and heat resistance of the resultant film. In addition, the reactive emulsifier is used to replace the conventional emulsifier. Thus, the drawbacks of the conventional emulsifier molecules migrate and desorb can be avoided when the polymer latex is stored.Design/methodology/approachThe cross-linked VAc-VeoVa10 latex has been synthesized with the reactive surfactants, in which VAc and VeoVa10 are used as the main monomers and ethylene glycol dimethacrylate (EGDMA) was used as the cross-linked monomer. Potassium persulfate (KPS) and mixed surfactants of alkyl allyl polyoxyethylene ether ammonium sulfate (JS-20) and allyl nonyl phenol polyoxyethylene ether (ANPEO-10) were used as the initiator and emulsifier, respectively. The structure of resultant latex film was characterized by Fourier transform infrared spectroscopy. The latex films were tested by thermogravimetric analysis, differential scanning calorimetry and contact angle (CA). The particle size and its distribution of the latex were measured by the nano particle size analyzer.FindingsThe factors that had an influence on the properties of the latex and the film were investigated in detail. The stability of the resultant latex is good. The average particles of the latex and its distribution are small and uniform, respectively. In comparison with the conventional latex film, the thermal stability and hydrophobicity of the resultant latex film are improved obviously.Practical implicationsThe resultant latex can be used in both the waterborne interior and exterior wall coatings, pickering stabilized waterborne polymer dispersions, polymer powders, environmentally friendly polymer-modified waterproof mortar and other fields, which can be satisfied with the high demand of thermal stability and hydrophobicity.Originality/valueThe modification of poly (VAc-VeoVa10) by reactive emulsifier and cross-linker is seldom reported. In this study, the cross-linked poly (VAC-VeoVa) latex is prepared through the reactive surfactants, with VAc and VeoVa10 used as the main monomers and EGDMA used as the cross-linked monomer. KPS and mixed surfactants of JS-20 and ANPEO-10 are used as the initiator and emulsifier, respectively.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2023
·
IF 7.4
Wei Wang,Xinsheng Li,Junan Shen,Fugen Yuan
Low temperature cracking is one of the main failures of asphalt pavements, specifically in cold areas. The ductility of asphalt binders at low temperature is one of the property indexes that are used to characterize cracking resistance of asphalt binders at low temperature. In order to improve the low temperature ductility of asphalt binders, butyl acrylate (BA) as soft monomer and vinyl acetate (VAc) as hard monomer were used for free radical polymerization, and the BA-VAc polymer was then used as a modifier to modify asphalt binders. The modification scheme was optimized by orthogonal test. The modified asphalt binders were mainly evaluated by ductility test and selected other properties. Atomic force microscopy (AFM) was used to investigate the nano-scaled morphology of modified asphalt binders. The results showed that 1) BA-VAc polymer could greatly improve the ductility of asphalt binders, highly depending on the type of base asphalts for their efficient. 2) The high temperature property of asphalt binder slightly decreased, but the compatibility and storage stability of the modified binders became poorly with the dose of BA-VAc polymer got larger and exceeded 6 %. 3) Ba-VAc polymer reduced the volume and number of “bee-like structures” in the 2D morphgraphic results, and also decreased the surface roughness and stiffness of modified binders. 4) The best performance of modified binders was observed for the modification scheme of a 6 % BA-VAc polymer and BA/VAc being a ratio of 6:4 which is produced at a shear temperature of 130 °C, a shear time of 5 min and a shear rate of 1000 r/min.
研究领域:
材料科学
·
土木工程
✓ 已验证
产品关联
DOI
高影响因子
Pigment & Resin Technology
·
2024
·
IF 1.3
Sipeng Fang,Zheqing Gong,Lijun Chen
PurposeThe purpose of this paper is that the long fluorocarbon monomer is used to modify the latex. The film of the resultant latex has the C-F bond with high bond energy and low surface energy, which can effectively improve the heat resistance and water resistance of the resultant film. In addition, a mixture of CO-436 and dibutyl maleate (DBM) as surfactants is used as the emulsifier, which brings the new application of the above surfactants.Design/methodology/approachThe modified Vac-VeoVa10 copolymer nanometre latex modified VAc-VeoVa10 latex has been successfully synthesized via the semi-continuous seeded emulsion polymerization, which VAc and VeoVa10 is used as the main monomers and long fluorocarbon monomer was used as the functional monomer. Potassium persulphate (KPS) and the mixture of CO-436 and DBM were used as the initiator and emulsifier, respectively. The structure of resultant latex film was characterized by Fourier transform infrared spectroscopy (FTIR). The latex films were tested by thermogravimetric analysis, differential scanning calorimetry and contact angle. The particle size and its distribution of the latex were measured by the nano particle size analyzer.FindingsDetailed investigation was conducted on the factors influencing the properties of the latex and film. The stability of the resultant latex is good. The average particles of the latex and its distribution are small and uniform, respectively. In comparison with the conventional latex film, the thermal stability and hydrophobicity of the resultant latex film are improved obviously.Originality/valueThe modification ofp(VAc-VeoVa10) using a new emulsifier and long fluorocarbon monomer has not been widely reported. In this study, the modified Vac-VeoVa10 copolymer nanometre latex modified VAc-VeoVa10 latex has been successfully synthesized via the semi-continuous seeded emulsion polymerization, which VAc and VeoVa10 is used as the main monomers and long fluorocarbon monomer was used as the functional monomer. KPS and the mixture of CO-436 and DBM were used as the initiator and emulsifier, respectively.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Pigment & Resin Technology
·
2024
·
IF 1.3
Lijun Chen,Wanting Zhao,Zheqing Gong
PurposeThe traditional VeoVa10-VAc copolymer latex, which prepared via the emulsion polymerization of the mixed monomers of VAc and VeoVa10, has the poor water resistance and thermal stability because of the migration of the conventional emulsifier molecules and the low bond energy of C-C bond. The purpose of this work is that the fluorinated monomer is used to modify the latex. The film of the resultant latex has the C-F bond with high bond energy and low surface energy, which can effectively improve the heat resistance and water resistance of the resultant film. In addition, the reactive emulsifier is used to replace the conventional emulsifier. The drawbacks of the conventional emulsifier molecules migrate and desorb can be avoided when the polymer latex is stored, thereby also improving the water resistance.Design/methodology/approachThe modified VAc-VeoVa10 latex has been successfully synthesized via the semi-continuous seeded emulsion polymerization, which VAc and VeoVa10 is used as the main monomers and HFMA was used as the functional monomer. KPS and reactive surfactants of SE-10 were used as the initiator and emulsifier, respectively. The structure of resultant latex film was characterized by Fourier transform infrared spectroscopy (FTIR). The latex films were tested by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and contact angle (CA). The particle size and its distribution of the latex were measured by the nano particle size analyzer.FindingsThe factors that had an influence on the properties of the latex and the film were investigated in detail. The stability of the resultant latex is good. The average particles of the latex and its distribution are small and uniform, respectively. In comparison with the conventional latex film, the thermal stability and hydrophobicity of the resultant latex film are improved obviously.Practical implicationsThe resultant latex can be used in both the waterborne interior and exterior wall coatings, pickering stabilized waterborne polymer dispersions, polymer powders, environmentally friendly polymer-modified waterproof mortar and other fields, which can be satisfied with the high demand of thermal stability and hydrophobicity.Originality/valueThe modification of poly (VAc-VeoVa10) by reactive surfactant and fluorinated monomer is seldom reported. In this study, the fluorinated poly (VAC-VeoVa) latex is prepared via the reactive surfactants, which VAc and VeoVa10 is used as the main monomers and hexafluorobutyl methacrylate is used as the functional monomer. Potassium persulfate (KPS) and allyl nonyl phenoxy propyl alcohol polyoxyethylene ether ammonium sulfate are used as the initiator and emulsifier, respectively.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2018
·Vol. 9
·期 23
·3215-3222
·
IF 4.927
Ni Zeng,Yuyan Yu,Junbing Chen,Xiao Meng,Leilei Peng,Yi Dan,Long Jiang
Although branched polymers find widespread applications, the rational design and synthesis of branched vinyl polymers via the conventional radical (co)polymerization of commercially available monomers is still a challenge for researchers in this field. Using branched polyvinyl acetate (PVAc) as a proof-of-concept, we report a facile approach to synthesize branched polymers via redox-initiated radical copolymerization. In this case, the commercially available monomer 2-(dimethylamino)ethyl methacrylate (DMAEMA), containing both a vinyl group and an initiator fragment (tertiary amine group), serves as an inimer in the presence of an oxidant to copolymerize with vinyl acetate (VAc), leading to the formation of branching architectures. The copolymerization kinetics investigation as well as electron paramagnetic resonance (EPR) measurements were conducted to reveal the reactivity of DMAEMA and the development of branching architectures, while TD-SEC and 1H-NMR were employed to study the structures of the resulted polymers. The results confirm that DMAEMA can serve as an inimer for the preparation of branched PVAc. Moreover, balancing the feed ratio of DMAEMA to VAc enables the fine control of branching degree. Within our experimental design, a high feed ratio of DMAEMA to VAc leads to high branching, as demonstrated by the Zimm branching factor, g′. This novel methodology involves only commercially available monomers and conventional radical polymerization and hence offers a promising future for preparing branched vinyl polymers on a large scale and at low cost.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
WATER RESEARCH
·
2024
·
IF 11.4
Chenxu Wang,Kangying Guo,Beibei Liu,Yue Gao,Qinyan Yue,Haijiao Xie,Baoyu Gao
The efficient removal of antibiotics and its combined pollutants is essential for aquatic environment and human health. In this study, a lignin-based organic flocculant named PRL-VAc-DMC was synthesized using pulp reject as the raw material, with vinyl acetate (VAc) and methacryloxyethyltrimethyl ammonium chloride (DMC) as the grafting monomers. A series of modern characterization methods were used to confirm the successful preparation of PRL-VAc-DMC and elucidate its polymerization mechanism. It was found that the Ph-OH group and its contiguous carbon atoms of lignin served as the primary active sites to react with grafting monomers. Flocculation experiments revealed that PRL-VAc-DMC could react with tetracycline (TC) through π-π* interaction, hydrophobic interaction, hydrogen bonding, and electrostatic attraction. With the coexistence of humic acid (HA) and Kaolin, the aromatic ring, hydroxyl, and amide group of TC could react with the benzene ring, hydroxyl group, and carboxyl group of HA, forming TC@HA@Kaolin complexes with Kaolin particles acting as the hydrophilic shell. The increase in particle size, electronegativity, and hydrophily of TC@HA@Kaolin complexes facilitated their interaction with PRL-VAc-DMC through strong interfacial interactions. Consequently, the presence of HA and Kaolin promoted the removal of TC. The synergistic removal mechanism of TC, HA, and Kaolin by PRL-VAc-DMC was systematically analyzed from the perspective of muti-interface interactions. This paper is of great significance for the comprehensive utilization of pulp reject and provides new insights into the flocculation mechanism at the molecular scale.
研究领域:
环境科学
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER BULLETIN
·
2024
·
IF 3.1
Gong Zheqing,Chen Lijun
Butyl acrylate, methyl methacrylate, vinyl acetate and tertiary vinyl carbonate (VeoVa10) are the main monomers, and alkyl alcohol polyether sulfosuccinate monoester sodium salt (A-6820) and alkyl alcohol polyoxyethylene ether (EFS-900) are used as the emulsifiers. Vinyl triethoxysilane is used as the modified monomers. Potassium persulfate is the initiator. The silicon-modified polymer latex is prepared via the semi-continuous seeded emulsion polymerization. The structure of the latex film is characterized by Fourier transform infrared spectroscopy. Latex films are tested by the thermogravimetric analysis, differential scanning calorimetry and contact angle. The particle size of the latex is measured with the zetatrac dynamic light scattering instrument. The conditions for preparing the resultant latex is optimized and obtained as follows: the amount of emulsifier is 6 wt%; the amount of initiator is 0.4 wt% and the amount of VETS is 4 wt%. The appearance of the resultant latex is translucent and blue, and the average particle size of the polymer latex and its distribution is small. The water contact angle increased from 68.07 to 91.00 °. Thermal decomposition temperature of the film of the silicone-modified polymer latex is 16.17 °C higher than that of the film of conventional polymer latex.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Protection of Metals and Physical Chemistry of Surfaces
·
2019
·Vol. 55
·期 3
·495-501
·
IF 0.787
Lijun Chen,Shao Tantan,Gong Yilu,Wang Xiuming
The novel poly (VAC-VeoVa-HFMA-BZMA) latex was successfully prepared via semicontinuous seeded emulsion polymerization which vinyl acetate (VAc) and vinyl ester of neodecanoic acid (VeoVa10) were main monomer, hexafluorobutyl methacrylate (HFMA) and benzyl methacrylate (BZMA) were used as functional monomer. Dodecyl benzene sulfonic acid sodium (SDBS), octylphenol polyoxyethylene ether (OP-10) and potassium persulfate (KPS) were used to be mixed emulsifier and initiator, respectively. The structure of the resultant latex is determined by Fourier transform infrared spectroscopy spectrum (FTIR). The thermal performances of latex film are studied via the thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The average particle size of the latex is characterized by the dynamic light scattering(DLS).Water contact angle (WCA) is used to test the wetting property of the novel poly (VAC-VeoVa-HFMA-BZMA) latex film. The condition of synthesizing the latex was studied in detail. The optimum condition of preparing the novel latex is that the amount of emulsifier is 8.0% (wt %) and the mass ratio of SDBS to OP-10 is 2 : 1 and the mass ratio of main monomer VAc to VeoVa10 is 3 : 1. The amount of initiator is 0.8% and the amounts of HFMA and BZMA are 6.0 and 8.0% (wt %), respectively. Results indicate that the water resistance of the latex film and thermal stability are improved when the fluorine and BZMA monomers are added.
研究领域:
高分子化学
·
材料科学
·
应用化学
·
功能材料
·
纳米材料
✓ 已验证
DOI
高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2013
·Vol. 172
·期 2
·701-712
·
IF 1.893
Cui Yanjun,Chen Xia,Li Yanfeng,Liu Xiao,Lei Lin,Zhang Yakui,Qian Jiayu
Using emulsion copolymer of styrene (St), glycidyl methacrylate (GMA) and 2-hydroxyethyl methacrylate (HEMA) as seed latexes, the superparamagnetic polymer emulsion particles were prepared by seeded emulsion copolymerization of butyl methacrylate (BMA), vinyl acetate (VAc) and ethylene glycol dimethacrylate in the presence of the seed latexes and superparamagnetic Fe 3 O 4 /SiOx nanoparticles (or Fe 3 O 4 -APTS nanoparticles) through a two-step process, without addition of any emulsifier. The magnetic emulsion particles named P(St-GMA-HEMA)/P(BMA-VAc) were characterized by transmission electron microscope and vibrating sample magnetometry. The results showed that the magnetic emulsion particles held a structure with a thinner shell (around 100 nm) and a bigger cavity (around 200 nm), and possessed a certain level of magnetic response. The resulting magnetic emulsion particles were employed in the immobilization of lipase by two strategies to immobilized lipase onto the resulting magnetic composites directly (S-1) or using glutaraldehyde as a coupling agent (S-2), thus, experimental data showed that the thermal stability and reusability of immobilized lipase based on S-2 were higher than that of S-1.
研究领域:
材料科学
·
生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2018
·
IF 5.158
Lei Chen,Zhouyi Xiong,Hanguo Xiong,Zhenjiong Wang,Zia-ud Din,Asad Nawaz,Pengkai Wang,Chun Hu
The nano-TiO 2 was utilized to improve the bonding performance, structure stability and film-forming properties of renewable starch-based wood adhesive. The results showed that 4% nano-TiO 2 (nano-TiO 2 :starch, w;w) resulted in 6.5 MPa of shear strength and 6437 Pa.s of viscosity. The thermal stability was measured by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Additionally, low-field nuclear magnetic resonance (NMR) and rheological results exhibited the enhancement of nano-TiO 2 on the pseudoplasticity and structure which determined the state and migration of water. Besides, the structural characterization of copolymer was analyzed via fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analysis (XRD). Furthermore, the film-forming property was evaluated by small angle X-ray scattering (SAXS) and dynamic mechanical analysis (DMA). The morphological structures of adhesive were observed by scanning electron microscopy (SEM). In conclusion, the 4% nano-TiO 2 (nano-TiO 2 :starch, w;w) can be employed to prepare starch-based wood adhesives with superior properties for wood application.
研究领域:
材料科学
·
木材科学与技术
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2016
·Vol. 133
·期 30
·
IF 1.866
Wei Gong,Meilan Li,Yunxiao Zang,Hao Xie,Bailing Liu,Hualin Chen
In order to control the impacts of blown sand in salty desert, in this article, the amphoteric emulsion, for the first time, was applied as an ecological sand-fixing material. This study started from the synthesis of the poly{vinyl acetate-dibutyl maleate-acrylamide-co-3-[ N -(2-methacroyloylethyl)- N, N -dimethylammonio]-propane sulfonate} [P(VAc-DBM-AM-DMAPS)] copolymer emulsion. Then, the structures, composition, thermal property of the emulsion were characterized by 1 H-NMR, FTIR, and DSC, respectively. The basic properties of the emulsion and salt tolerance of the latex films were measured by using viscometer, dynamic light scattering, and laser Doppler electrophoresis also. And the sand-fixing properties of the emulsion were evaluated. Finally, the influence of the emulsion on the growth of soil microbe and plants were discussed for understanding its ecological effect. The experimental results showed that the emulsion has been successfully synthesized and could be as an ecological sand-fixing material. The related reason is that, first, the emulsion could significantly improve the compressive strength and water retaining; second, the emulsion had good thermal aging, freeze-thaw stabilities and salt tolerance to withstand the changes in temperature and NaCl concentration of salty desert; third, the influence of the emulsion on the growth of plants and microbe of sand also showed a dependable ecological effect. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133 , 43715.
研究领域:
材料科学
·
环境科学
·
生态学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）