Polymer Chemistry
·
2014
·Vol. 5
·期 15
·4561-4568
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IF 5.368
Deyang Yu,Chunhui Luo,Wenxin Fu,Zhibo Li
Five (meth)acrylamide derivatives containing alanine ester/amide residues were synthesized and then polymerized using RAFT polymerization. After polymerization and further treatment of the obtained polymers with excess radical initiators, we obtained a series of homopolymers with well-defined molecular weights and end groups. Depending on the structure of side-chain terminal groups, these alanine-containing homopolymers displayed thermal-responsive behaviors in water. Samples containing a methyl ester group, i.e., poly(MA-L-Ala-OMe) and poly(Ac-L-Ala-OMe), showed low critical solution temperature (LCST) behaviors. Replacing methyl ester with ethyl or isopropyl ester groups caused loss of thermal-responsive properties. However, replacing the isopropyl ester with isopropyl amide groups can regain thermal-responsive polymers such as poly(MA-L-Ala-iPA). We further studied the LCST behaviors of these three homopolymers with respect to the degree of polymerization (DP), concentration, salt concentration, and chirality of amino acids. It was found that the cloud point (CP) decreased with increasing polymer concentration, DP and salt concentration. The CPs of the polymers prepared from a pair of enantiomers showed no distinct difference, while the random copolymer of the two enantiomers displayed higher CP than optically pure homopolymers.
研究领域:
高分子化学
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材料科学
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 139
·期 20
·52140
·
IF 3.057
Shoucun Zhang,Shengyan Wang,Yujing Bian,Min Xue,Shengwei Guo,Wenli Wu
Utilizing 2,2′-azobis(isobutyronitrile) (AIBN) as the initiator, the copolymerization of methyl methacrylate/methacrylate acid is performed by precipitation copolymerization. The effects of pressure, initiation concentration, the methacrylic acid (MA) concentration, and small amount of water are investigated separately. The morphology and molecular weight are analyzed by scanning electron microscopy and gel permeation chromatography, respectively. The results indicates that the concentration of MA or AIBN affects the molecular weight greatly, and the maximum molecular weight reaches 213 kDa. The morphology of samples exhibits a certain degree of agglomeration. Most samples are obtained as free-flowing powder with numerous spherical bulges under a proper polymerization condition.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2018
·
IF 3.141
Changfa Xiao,Yuyan Yu,Long Jiang,Yi Dan
Aluminum trichloride (AlCl3) catalyzed copolymerization of polar monomers, including both methyl methacrylate (MMA) and methyl acrylate (MA), with nonpolar 1-octene is investigated. The copolymerization of MMA and 1-octene produces copolymers with acceptable productivity in the present of AlCl3, but no alternating copolymer can be obtained even in a 1-octene rich condition (n(1-octene)/n(MMA) = 6.14/1). However, AlCl3-catalyzed copolymerization of MA and 1-octene unveils that MA is more feasible than MMA to copolymerize with 1-octene for the formation of alternating copolymer. An alternating copolymer of MA and 1-octene can be obtained even at MA-rich conditions (n(1-octene)/n(MA) = 0.58/1). Meanwhile, temperature shows a significant impact on the copolymerization behaviors. Performing AlCl3-catalyzed copolymerization of MA and 1-octene at lower temperature leads to an increase in the molecular weight and the incorporation of MA into the backbone of the copolymer, probably due to low temperature-enhanced complexation between AlCl3 and the ester functionality.
研究领域:
高分子化学
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催化化学
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2012
·Vol. 128
·期 6
·4261-4270
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IF 1.289
Wensong Han,Baoping Lin,Hong Yang,Xueqin Zhang
First, the second-generation hyperbranched poly(amine-ester) (G2-OH) was successfully prepared by thiol-ene “click” chemistry. Subsequently, a series of photosensitive hyperbranched oligomers (G2-ORs) were synthesized by facile modifications of the G2-OH with acryloyl chloride, methacryloyl chloride, IPDI-HEA, and IPDI-HEMA, respectively. The structures of hyperbranched oligomers were characterized by element analysis, FT-IR, 1 H NMR, GPC and viscosity measurement. It was shown that these synthesized oligomers have narrow molecular weight distribution and low intrinsic viscosity at 30°C. UV–vis spectra results showed that the G2-ORs had sharp absorption bands at around 202 nm. The results of photosensitivities measurement indicated that the G2-Macr shows the highest photosensitive than other hyperbranched oligomers in the absence of photoinitiator. In addition, these UV-cured photosensitive G2-ORs had good thermal properties. The solubilities of the synthesized hyperbranched oligomers were also examined. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
研究领域:
材料科学
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高分子化学
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2017
·Vol. 135
·期 8
·45894
·
IF 1.86
Zhancong Lin,Weiqu Liu,Jianquan Tan
A (meth)acrylate copolymer grafted with long fluorinated side chains (AGLF) was synthesized successfully through a two-step procedure. First, a carboxyl terminated fluoropolymer, poly(2,2,3,4,4,4-hexafluorobutyl methacrylate) was synthesized by conventional radical polymerization in the presence of 3-mercaptopropionic acid as chain transfer agent. And then the fluoropolymer was grafted to the in-house synthesized polyacrylate (MMA -r- BA -r- GMA). Fourier transform infrared spectroscopy and 1 H-nuclear magnetic resonance spectroscopy were employed to verify the synthesis of AGLF. Moreover, the surface properties were investigated by contact angle measurement and X-ray photoelectron spectroscopy. The results proved that a small amount of poly(2,2,3,4,4,4-hexafluorobutyl methacrylate) addition can create a hydrophobic surface effectively. Furthermore, the X-ray photoelectron spectroscopy results showed that it is the AGLF grafted with longer fluorinated side chain that have more fluorine atoms enriched on the surface and thus performed better hydrophobicity and lipophobicity. Testified by thermogravimetric analysis and differential scanning calorimetry, it was found that AGLF films have excellent thermal properties. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 45894.
研究领域:
材料科学
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高分子化学
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产品关联
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
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2016
·
IF 2.632
Jianquan Tan,Weiqu Liu,Honglei Wang,Yang Sun,Shijian Wang
A novel waterborne UV-curable comb-like (meth)acrylate graft copolymer containing long fluorinated side chains (UVWCAC) was synthesized by conventional radical copolymerization of a novel mono-methacryloyloxy terminated fluorinated macromonomer (PHFBMA-GMA) and (meth)acrylate monomers. GPC, FTIR and 1 H NMR were employed to characterize the structure of the polymers. The influence of both the molecular weight and concentration of PHFBMA-GMA on the properties of UV-cured films was investigated. Hydrophobic surface could be obtained with just small amount of PHFBMA-GMA copolymerized into the polymer. The surface energy of UV-cured films decreased as both the concentration and the molecular weight of PHFBMA-GMA increased. The surface composition of the graft copolymer was characterized by XPS. XPS results confirmed the enrichment of the fluorine atoms on the surface quantitatively. In addition, the physical properties of UVWCAC UV-cured films, such as gel content, water absorption, pencil hardness, adhesion, chemical resistance, mechanical properties, optical transmittance and thermal properties were also investigated in detail. The novel UVWCAC prepared via conventional radical polymerization not only had excellent properties but also had the prominent potential application in large scale industrialization.
研究领域:
高分子化学
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材料科学
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表面科学
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功能材料
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涂层技术
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DOI
高影响因子
Journal of Macromolecular Science Part A-Pure and Applied Chemistry
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2018
·
IF 1.057
Sha He,Weiqu Liu,Chunhua Liu,Chi Jiang,Maiping Yang,Zhengfang Wang
Two waterborne poly(meth)acrylates containing fluorinated side chains (PALF and PASF) were synthesized by conventional radical copolymerization. Then waterborne epoxy composites with hydrophobic surface were obtained through a phase-inversion emulsion technique, using the PALF and PASF acrylates as reactive surface additives. Contact angle measurements and X-ray photoelectron spectroscope were employed to characterize the surface properties and the results confirmed that the fluorine atoms in the longer fluorinated side chains migrated to the outmost layer more efficiently. The effect of the fluorinated content and the length of the fluorine side chain on thermal and bulk properties of the waterborne epoxy resin was investigated. With increasing the fluorinated content or the length of the fluorine side chain, the contact angles and thermal properties improved while the mechanical properties showed no deterioration.
研究领域:
高分子化学
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材料科学
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表面科学
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涂层技术
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功能材料
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DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 41
·34364-34375
·
IF 3.289
Jianquan Tan,Weiqu Liu,Zhengfang Wang
A series of waterborne UV-curable comb-shaped (meth)acrylate graft copolymers containing long fluorinated and/or siloxane side chains were synthesized by conventional radical copolymerization of a novel mono-methacryloyloxy terminated fluorinated macromonomer (PHFA-GMA) and/or polysiloxane macromonomer (SiOHMAC) with (meth)acrylate monomers. The separate effects of PHFA-GMA and SiOHMAC, as well as the synergic effect of these two components, on the properties, especially the surface properties were investigated in detail. A hydrophobic surface could be obtained with extremely low content of PHFA-GMA and/or SiOHMAC due to the strong tendency of the macromonomers to migrate towards the outmost layer, resulting in abundant enrichment of fluorine and silicon atoms on the surface. XPS (X-ray photoelectron spectroscopy) results revealed that for a given weight of the two macromonomers, Si atomic concentration of the copolymer modified by SiOHMAC is higher than F atomic concentration of the copolymer modified by PHFA-GMA. AFM (atomic force microscopy) images showed that surface of the copolymer modified by SiOHMAC is rougher than that modified by PHFA-GMA. Compared to PHFA-GMA, SiOHMAC had higher efficiency and effectiveness in creating hydrophobic surfaces. In addition, the influence of PHFA-GMA and/or SiOHMAC on the physical properties, such as water dispersion particle size, water absorption, pencil hardness, adhesion, mechanical properties and thermal properties were also investigated. The novel comb-shaped copolymers prepared via conventional radical polymerization not only had excellent properties but also have potential applications in large scale industrialization.
研究领域:
材料科学
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高分子化学
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产品关联
DOI
高影响因子
LANGMUIR
·
2025
·
IF 3.9
Longben Huo,Hui Feng,Jiwei Cui,Ying Zhu,Lingyun Zhu,Xin Jin,Xinyuan Zhu
Polyvinylidene fluoride (PVDF) latex nanoparticles serve as a versatile platform for surface modification due to their role as precursors in PVDF manufacturing. However, the strong chemical stability and poor compatibility of PVDF present significant challenges for effective surface modification. To address this, we developed a method that facilitates surface modification through chain entanglement. By employing monomer swelling emulsion polymerization, poly(meth)acrylate (PA) monomers are incorporated into PVDF nanoparticles and subsequently polymerized. Rheological properties and transmission electron microscopy mapping confirmed the chain entanglement between PVDF and PA, indicating a successful integration. This method is efficient, straightforward, and highly adaptable, making it well-suited for large-scale industrial production.
研究领域:
材料科学
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高分子化学
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纳米技术
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化学工程
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产品关联
DOI
PubMed
高影响因子
Polymer Chemistry
·
2019
·Vol. 10
·期 16
·2073-2082
·
IF 4.76
Yujie Zhu,Yang Xue,Xiaohua Li,Jianhua Zhang,Ruiwei Guo
Regioselective addition of nonsymmetrical monomers in radical polymerization is a basic issue for control of the kinetics and structure of the resulting products. In RAFT polymerization, head addition generates primary alkyl adducts trapped by RAFT agents. Due to the low leaving ability of primary alkyl radicals, this kind of adduct in RAFT polymerization will become non-active macro-RAFT agents, i.e., dead dormant species (DDS). The contents of non-active macro-RAFT agents in RAFT polymerization of three acrylates (ethyl, butyl, and 2-ethylhexanyl acrylate), two methacrylates (ethyl and butyl methacrylate) and styrene were determined by a combination technology of RAFT block polymerization derivation and gradient polymer elution chromatography. The head addition incidences of these monomers were estimated according to our previously proposed formula between the DDS content and head addition incidence. The results showed that the number or type of side chains both had significant influence on head addition incidence, with incidence of methacrylates and styrene about one order of magnitude smaller than that of acrylates due to steric repulsion effects. The results also showed that DDS contents would accumulate with increased degree of polymerization. Therefore, head addition played an important role in acrylate RAFT polymerization when product composition was considered, especially for polymers of high molecular weight.
研究领域:
高分子化学
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材料科学
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DOI
高影响因子
WATER RESEARCH
·
2024
·
IF 11.4
Chao Chen,Yu Yang,Chung-Hak Lee,Satoshi Takizawa,Zhenghua Zhang,How Yong Ng,Li-an Hou
Membrane biofouling is a challenge to be solved for the stable operation of the seawater reverse osmosis (SWRO) membrane. This study explored the regulation mechanism of quorum sensing (QS) inhibition on microbial community composition and population-level behaviors in seawater desalination membrane biofouling. A novel antibiofouling SWRO membrane (MA_m) by incorporating one of quorum sensing inhibitors (QSIs), methyl anthranilate (MA) was prepared. It exhibited enhanced anti-biofouling performance than the exogenous addition of QSIs, showing long-term stability and alleviating 22 % decrease in membrane flux compared with the virgin membrane. The results observed that dominant bacteria Epsilon- and Gamma-proteobacteria ( Shewanella, Olleya, Colwellia, and Arcobacter ), which are significantly related to ( P ≤ 0.01) the metabolic products (i.e., polysaccharides, proteins and eDNA), are reduced by over 80 % on the MA_m membrane. Additionally, the introduction of MA has a more significant impact on the QS signal-sensing pathway through binding to the active site of the transmembrane sensor receptor. It effectively reduces the abundance of genes encoding QS and extracellular polymeric substance (EPS) (exopolysaccharides (i.e., galE and nagB ) and amino acids (i.e., ilvE, metH, phhA , and serB )) by up to 50 % and 30 %, respectively, resulting in a reduction of EPS by more than 50 %, thereby limiting the biofilm formation on the QSI-modified membrane. This study provides novel insights into the potential of QSIs to control consortial biofilm formation in practical SWRO applications.
研究领域:
环境工程
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生物技术
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微生物学
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水处理
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）