JOURNAL OF APPLIED POLYMER SCIENCE
·
2017
·Vol. 134
·期 48
·45510
·
IF 1.86
Chunmiao Xia,Yingwu Luo
Bitumen emulsions have often been modified by styrene–butadiene rubber latex. The modified bitumen can have excellent low-temperature cracking resistance, but rutting resistance at high temperature still remains poor. In the current work, for the first time, a stable poly(styrene- b -isoprene- b -styrene) (SIS) triblock copolymer latex is synthesized by reversible addition–fragmentation transfer (RAFT) emulsion polymerization. Based on this, a simple heterocoagulation process is developed to prepare the bitumen emulsions modified by SIS. The heterocoagulation results in hybrid particles of SIS shell and bitumen core. With addition of 5 wt % SIS, a continuous polymer-rich phase could be formed in the modified bitumen once the modified emulsion was broken down. The bitumen modified by 5 wt % SIS shows a significant increase in complex modulus at high temperature and a significant decrease in loss tangent, suggesting excellent resistance to rutting at high temperature, which is consistent with the significant increase in softening point from 41 °C for the base bitumen up to 64 °C. Meanwhile, the ductility at 5 °C of the modified bitumen is also dramatically increased from 1.4 cm for the base bitumen to 40 cm, indicating the low-temperature cracking resistance should also be much enhanced. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45510.
研究领域:
材料科学
·
高分子科学
·
土木工程
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DOI
高影响因子
CELLULOSE
·
2020
·Vol. 27
·期 14
·8155-8167
·
IF 4.21
Guo Jianwei,Liu Xiao,Han Miaomiao,Liu Yadong,Ji Shengxiang
Abstract An amphoteric metal adsorbent, poly( N -acryloyl- l -histidine)-modified sawdust (SD- g -P(A-His)), is prepared by reversible addition–fragmentation chain transfer (RAFT) polymerization of N -acryloyl- l -histidine from modified sawdust. SD- g -P(A-His) possess imidazolyl and carboxyl groups and shows outstanding adsorption performance for heavy metals. The adsorption capacities of SD- g -P(A-His) are 241.8 and 95.7 mg/g for Pb(II) and Cu(II), respectively. Ten tested metal ions, e.g. Au(III), Cr(III), Cu(II), Fe(III), Ni(II), Pb(II), Pd(II), Hg(II), Mg(II) and Zn(II), can be effectively removed from the multi-metal solution at pH > 2.7, while Au(III) and Pd(II) can be selectively recycled from the multi-metal solution by lowering the pH to ≤ 1.0. The adsorption kinetics of Pb(II) and Cu(II) onto SD- g -P(A-His) fit well with the pseudo-second order model. SD- g -P(A-His) can treat the water with low concentration of metal ions down to sub-10 μg/L level to meet the Quality Standards for Drinking Water of China. Moreover, SD- g -P(A-His) can be recycled and maintain high adsorption efficiency (91.5%) even after 5 cycles. Graphic abstract
研究领域:
环境科学
·
材料科学
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DOI
高影响因子
Polymers
·
2023
·Vol. 15
·期 2
·394
·
IF 5
Xuan Liu,Wanning Mao,Jie Gong,Haiyu Liu,Yanming Shao,Liyu Sun,Haihua Wang,Chao Wang
In order to enhance the electrochemical performance and mechanical properties of poly(ethylene oxide) (PEO)-based solid polymer electrolytes, composite solid electrolytes (CSE) composed of single-ion conducting polymer-modified SiO2, PEO and lithium salt were prepared and used in lithium-ion batteries in this work. The pyridyl disulfide terminated polymer (py-ss-PLiSSPSI) is synthesized through RAFT polymerization, then grafted onto SiO2via thiol-disulfide exchange reaction between SiO2-SH and py-ss-PLiSSPSI. The chemical structure, surface morphology and elemental distribution of the as-prepared polymer and the PLiSSPSI-g-SiO2nanoparticles have been investigated. Moreover, CSEs containing 2, 6, and 10 wt% PLiSSPSI-g-SiO2nanoparticles (PLi-g-SiCSEs) are fabricated and characterized. The compatibility of the PLiSSPSI-g-SiO2nanoparticles and the PEO can be effectively improved owing to the excellent dispersibility of the functionalized nanoparticles in the polymer matrix, which promotes the comprehensive performances of PLi-g-SiCSEs. The PLi-g-SiCSE-6 exhibits the highest ionic conductivity (0.22 mS·cm−1) at 60 °C, a large tLi+of 0.77, a wider electrochemical window of 5.6 V and a rather good lithium plating/stripping performance at 60 °C, as well as superior mechanical properties. Hence, the CSEs containing single-ion conducting polymer modified nanoparticles are promising candidates for all-solid-state lithium-ion batteries.Keywords:composite solid electrolyte;single-ion conducting polymer grafting;SiO2modification;RAFT polymerization;all-solid-state battery
研究领域:
材料科学
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电化学
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聚合物化学
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电池技术
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DOI
高影响因子
MACROMOLECULES
·
2026
·
IF 5.2
Yen-Ling Kuan,Yu-Chun Chiu,Yun-Sheng Ye,Shiao-Wei Kuo
In this study, the chain end of a reversible addition–fragmentation chain transfer (RAFT) polymerization agent of poly(cyclohexene carbonate) (PCHC) was synthesized via the ring-opening copolymerization of CO2 and cyclohexene oxide (CHO) by using s-dodecyl-s’-(α,α′-dimethyl-α″-acetic acid) trithiocarbonate (DDMAT) as a chain transfer agent. Various block copolymers of poly(cyclohexene carbonate)-b-poly(styrene-alt-N-(hydroxyphenyl)maleimide) (PCHC-b-PSHPMI) were subsequently synthesized by the RAFT copolymerization of styrene and N-(hydroxyphenyl)maleimide (HPMI) in the presence of azobis(isobutyronitrile) (AIBN), which were characterized by using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR), and gel permeation chromatography (GPC). DSC thermal analyses indicated that the single Tg values were observed for all PCHC-b-PSHPMI copolymers, indicating miscible behavior, and the Tg value was 194 °C for the PCHC-b-PSHPMI78 copolymer. One- and two-dimensional (2D) FTIR spectroscopy revealed that these PCHC-b-PSHPMI copolymers actually provide relatively weak intermolecular O–H···O═C hydrogen bonding, which was attenuated by the self-association of hydrogen bonding within the pure PCHC and pure PSHPMI segments. In the solid-state 13C NMR spectra, a pronounced chemical shift variation of the C–OH and C═O units of the PSHPMI segment and C═O units of the PCHC segment was also observed, which is attributable to the intermolecular hydrogen interactions in these PCHC-b-PSHPMI copolymers. Rotating-frame 1H spin–lattice relaxation [T1ρ(H)] analyses also indicated the complete miscible behavior of these block copolymers within the 2–3 nm length scale, and the relaxation times exhibited positive deviations from the linear predicted rule. These results suggest that the loose chain structure was formed because of the weaker intermolecular hydrogen bonding between the PCHC and PSHPMI segments in the block copolymers.
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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.
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DOI
高影响因子
MOLECULES
·
2022
·Vol. 27
·期 10
·3214
·
IF 4.927
Yi Gao,Xuesong Yao,Qinggeng Jiang,Jianhe Liao,Yongping Chen,Rentong Yu
Microgels have unique and versatile properties allowing their use in forward osmosis areas as a draw agent. In this contribution, poly(4-vinylpyridine) (P4VP) was synthesized via RAFT polymerization and then grafted to a poly(N-Isopropylacrylamide) (PNIPAAm) crosslinking network by reverse suspension polymerization. P4VP was successfully obtained by the quasiliving polymerization with the result of nuclear magnetic resonance and gel permeation chromatography characterization. The particle size and particle size distribution of the PNIPAAm-g-P4VP microgels containing 0, 5, 10, 15 and 20 wt% P4VP were measured by means of a laser particle size analyzer. It was found that all the microgels were of micrometer scale and the particle size was increased with the P4VP load. Inter/intra-molecular-specific interactions, i.e., hydrogen bond interactions were then investigated by Fourier infrared spectroscopy. In addition, the water flux measurements showed that all the PNIPAAm-g-P4VP microgels can draw water more effectively than a blank PNIPAAm microgel. For the copolymer microgel incorporating 20 wt% P4VP, the water flux was measured to be 7.48 L∙m−2∙h−1.Keywords:microgel;forward osmosis;draw agent;P4VP
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产品关联
DOI
PubMed
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2021
·
IF 8.528
Yaofeng Zhu,Wei Liu,Hongbo Dai,Farao Zhang
This experimental study focuses on the development of an amphiphilic sizing agent to improve the interfacial adhesion and the mechanical properties of short glass fiber (GF)/polypropylene (PP) composites. To solve the critical compatible issue between the hydrophilic GF and the hydrophobic PP, we strategically utilized the reversible addition-fragmentation chain-transfer (RAFT) polymerization to self-assemble and synthesize an amphiphilic sizing agent. This surfactant-free sizing agent can create hydrogen bonds and electrostatic adsorption on GF surfaces and meanwhile can form molecular entanglements , alkyl cations, and σ-π conjugates with PP matrix. The FT-IR analysis shows that a large number of hydrogen bonds are formed on the sizing agent-GF interface. Additionally, the SEM micrographs of the composite fracture surfaces demonstrate strong interfacial compatibility between the sized-GF and the PP matrix. Comparing with the neat GF/PP composites, the tensile and flexural strength of the sized-GF/PP composites are increased by 25.8% and 33.1%, respectively. Their tensile strength and young's modulus are in close agreement to the analytical calculations. In short, this paper presents a new RAFT-based methodology to develop the amphiphilic sizing agents that are able to improve the interfacial compatibility of GF/PP composites and also can be transferred towards real applications for enhancing the mechanical properties of fiber-reinforced composites.
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产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2016
·
IF 3.485
Tao Chen,Xiaohua Han,Zhi Peng,Aihua Li,Jingquan Liu
7, 8-Dihydroxyflavone (7, 8-DHF) is an effective drug for the treatment of Parkinson’s disease. However, its application is heavily limited by its poor water solubility. To improve its hydrophilicity, biocompatible poly (ethylene glycol)acrylate (PEG-A) was grafted onto 7, 8-DHF via in situ reversible addition-fragmentation chain transfer (RAFT) polymerization, forming a kind of a drug/polymer composite, DHF/PPEG-A. It was found that the solubility of DHF/PPEG-A was significantly improved by 78 times compared to the unmodified precursor. Impressively, both the cytotoxicity and the drug efficacy of the synthesized DHF/PPEG-A just slightly decreased compared with the unmodified 7, 8-DHF. Moreover, the drug efficacy of DHF/PPEG-A can be regained by the hydrolysis in the presence of the esterase D due to the decomposition to 7, 8-DHF in body. This dramatical improvement of the water solubility of DHF/PPEG-A and the insignificant compromise of its drug cytotoxicity could envision extensive practical clinical administration of 7, 8-DHF for enhanced drug efficacy.
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DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2014
·
IF 6.451
Lijuan Zhao,Faqiong Zhao,Baizhao Zeng
A novel water-compatible fenitrothion imprinted polymer was prepared on Au nanoparticles (AuNPs) by click chemistry and reversible addition–fragmentation chain transfer (RAFT) precipitation polymerization (RAFTPP). The RAFT chain-transfer agent was synthesized on the surface of AuNPs using click chemistry, then an imprinted polymer with hydrophilic polymer brushes was prepared on the RAFT chain-transfer agent modified AuNPs by RAFTPP, mediated by hydrophilic polyethylene glycol macromolecular cochain-transfer agent. The obtained molecularly imprinted material showed improved accessibility to fenitrothion and recognition property in water medium. When the material was immobilized on an ionic liquid functionalized graphene coated glassy carbon electrode for the electrochemical determination of fenitrothion, the resulting electrochemical sensor presented linear response in the range of 0.01−5 μM, with a sensitivity of 6.1 μA/μM mm 2 . The low limit of detection was 8 nM (S/N=3). The sensor was successfully applied to the determination of real samples and the recovery for standard added was 95−108%.
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Jingxian Fan,Xiaole Gong,Honglei Liu,Mengyu Cao,Xiuping Liu,Xueying Cao,Liang Cui,Jinhou Fang,Jingquan Liu
Viscose fiber (VF) has been attracting increasing interest owing to its varied advantages like high breathability, high moisture absorption, superior spinning properties, and wear comfort. It can be employed in a multitude of medical applications, including wound care, hygiene products, surgical gowns, sutures, and bed linen. In this paper, RAFT polymerization was utilized to functionalize and modify VF, thereby preparing two kinds of distinct functional materials. The first one is viscose fiber grafted with poly (acrylic acid) and complexed with metal ions (VF-g-PAA-metal ions), which is applied in the domain of antimicrobial. Experimental findings demonstrated that the as-fabricated three composite materials of VF-g-PAA-Ag, VF-g-PAA-Cu, and VF-g-PAA-Zn exhibit significant inhibitory effects on Escherichia coli and Staphylococcus aureus . The second one is viscose fiber grafted with poly (acrylic acid) and then modified with NH 3 + to afford a composite material of VF-g-PAA-NH 3 + , which displays efficient formaldehyde (HCHO) removal efficiency via the formation of an oxime bond (-N=CH 2 ), while generating the only by-product of H 2 O. Our study reveals that 1.0 g of VF-g-PAA-NH 3 + is capable of removing 229.39 mg of HCHO in 24 h at a flow rate of 1.0 L min −1 N 2 at 25 °C. This approach improves the antimicrobial and HCHO removal efficacy of VF. The current novel and environmentally friendly modification strategy not only endows VF materials with antibacterial properties and formaldehyde (HCHO) elimination capabilities, but also exhibits significant environmental compatibility, thereby significantly expanding their applications.
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DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2012
·Vol. 213
·期 20
·2192-2200
·
IF 2.361
Xiao-Hui Dai,Chun-Yan Hong,Cai-Yuan Pan
A novel double-hydrophilic block copolymer P(MEO 2 MA- co -OEGMA)- b -PAMA has been successfully synthesized by two-step RAFT polymerization. Then, the amino groups of PAMA blocks in the copolymers react with 1-pyrenecarboxaldehyde via a “Schiff-base” reaction, and the resulting copolymers are self-assembled to form spherical micelles in aqueous solution. Because the “Schiff-base” linkage is pH sensitive, the release rate of pyrene depends upon the pH of solution. Complete release is achieved at pH 1, and the control release is much faster at pH 5.5 than that at pH 7.4. With progress of pyrene release, the micelles are disassembled gradually and disappeared completely at last. This double-hydrophilic copolymer is a promising candidate of drug carrier for the aldehyde- containing hydrophobic drugs.
研究领域:
高分子化学
·
药剂学
·
纳米医学
·
生物材料
·
药物递送系统
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DOI
高影响因子
COLLOID AND POLYMER SCIENCE
·
2014
·Vol. 292
·期 10
·2633-2645
·
IF 2.41
Cong Houluo,Zheng Sixun
In this contribution, we reported the synthesis of poly( N -isopropylacrylamide)- block -poly(acrylic acid) (PNIPAAm- b -PAA) copolymer networks via sequential reversible addition-fragmentation chain transfer (RAFT) polymerization. The PNIPAAm- b -PAA block copolymer networks were characterized by means of Fourier transform infrared spectroscopy (FTIR) and small angle X-ray scattering (SAXS). The volume phase transition (VPT) temperatures of the PNIPAAm- b -PAA hydrogels were measured by means of micro-differential scanning calorimetry (micro-DSC). It was found that the block copolymer hydrogels displayed the VPT temperatures lower than the control PNIPAAm hydrogel. Compared to the control PNIPAAm hydrogel, the deswelling and reswelling properties of the block copolymer hydrogels were significantly improved. The improved thermoresponsive properties of the PNIPAAm- b -PAA hydrogels have been interpreted on the basis of the formation of the architecture of the block copolymer networks.
研究领域:
高分子化学
·
生物材料
·
药物递送
·
组织工程
·
智能响应材料
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DOI
高影响因子
危险品化学品经营许可证（带存储）