POLYMER INTERNATIONAL
·
2020
·Vol. 70
·期 3
·282-287
·
IF 2.574
Jiaxin Wei,Yingshuang Shang,Da Xu,Zhaoyang Wang,Zilong Jiang,Yanwei Gao,Haibo Zhang
A series of novel poly(ether ketone) copolymers with different contents of fluorene groups were synthesized. The effects of fluorene group content on the thermal and mechanical properties of poly(ether ketone) copolymers were investigated. The introduction of a low content of fluorene groups can lead to an increase in glass transition temperature, thermal stability and heat deflection temperature. Among them, the heat deflection temperature of 10% fluorene-containing poly(ether ketone) copolymers (PEK-FD10) increases from 178 °C (pure poly(ether ketone)) to 196 °C, which means that the material has a higher heat resistance rating. Compared with poly(ether ketone)s, these copolymers have excellent mechanical properties. When the content of fluorene groups is only 2% (PEK-FD2), the strength is significantly improved. And the flexural strength of PEK-FD2 is 149.3 MPa, which is 12% higher than that of poly(ether ketone). It is worth noting that the fracture toughness and impact toughness are also increased significantly. The strain at break of PEK-FD2 is up to 88% and the impact toughness of PEK-FD2 is 54.6 J m −1 . This suggests that the introduction of minute contents of fluorene groups can simultaneously increase the strength and toughness. © 2020 Society of Industrial Chemistry
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2018
·Vol. 25
·期 9
·1-8
·
IF 1.434
Ji Changwei,Liu Jingcheng,Zheng Xiangfei,Liu Ren,Yuan Yan,Liu Xiaoya,Mu Qidao
Cholic acid is a class of biological compounds that exhibit valuable properties, and have been applied in many fields due to its special chemical structures for many areas. In this study, poly[(methacrylic acid tert-butyl cholate ester)- co -(acetoxy styrene)] [P(MATC- co -AS)] was synthesized from cholic acid, then the final copolymer poly[(methacrylic acid tert-butyl cholate ester)- co -(p-hydrostyrene)] [P(MATC- co -HS)] was obtained after P(MATC- co -AS) was hydrolysized. The structure and properties of the copolymers were determined through nuclear magnetic resonance, gel permeation chromatography, UV spectrometry, thermogravimetric analysis, and differential scanning calorimetry. The ultraviolet spectra of the copolymers indicate that they exhibit excellent optical transmittance at 248 nm. Moreover, the photolithography performance of a positive-tone photoresist based on the copolymers were evaluated using an KrF laser exposure system. The results indicate that a resolution of 0.25 μm could be achieved at a low exposure dose.
研究领域:
材料科学
·
生物化学
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产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Jie Jiang,Wen-Jun Wang,Bo-Geng Li,Shiping Zhu
The tactics of targeting copolymer composition (CC) and molecular weight (MW) via semibatch controlled radical polymerization (CRP) have been extensively studied. However, little effort is made to target copolymer sequence length (CSL) and its triad sequence, which are among the key microstructures determining material properties of the copolymers. This work presents a method to design and synthesize targeted CSL and copolymer triads in a reversible addition–fragmentation chain transfer radical mini-emulsion copolymerization system (RAFT) through a semibatch chain and sequence model coupled with Alfrey Mayo model. The kinetic model was first derived and correlated with experimental results of the batch St/BA copolymerizations. The semibatch RAFT model was then employed to calculate the feed-rate to target CSL and their triads. St/BA copolymers with different uniform CSLs and their triads are synthesized through the programmed semibatch RAFT mini-emulsion copolymerization processes.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
JOURNAL OF INCLUSION PHENOMENA AND MACROCYCLIC CHEMISTRY
·
2019
·Vol. 96
·期 1
·69-79
·
IF 1.429
Duan Nannan,Ye Lin,Zhang Ai-ying,Feng Zeng-guo
Abstract A series of PPR-based multiblock copolymers were prepared by using a PPR self-assembled from a distal 2-bromoisobutyryl end-capped ferrocenyl containing derivative Br-TEG-Fc-TEG-Br with 4 β-CDs as initiator to initiate the in situ ATRP of NIPAAm in aqueous solution at room temperature. After the ATRP, about 2 β-CDs were resided on the polymeric backbone through a 7 day dialysing purification, but those β-CDs were all slipped off the polymeric chain through a further 7 day dialysing treatment. It suggested that the resulting multiblock copolymers are really the PPR-based instead of the PR-based ones showing an impeded dethreading behavior of β-CDs and the PNIPAAm blocks attached are not bulky enough as polymeric stoppers to end-cap the β-CD-TEG-Fc-TEG PPRs into the PR-based multiblock copolymers. Graphic abstract A series of PPR-based multiblock copolymers were prepared by using a PPR self-assembled from Br-TEG-Fc-TEG-Br with 4 β-CDs as initiator to initiate the aqueous ATRP of NIPAAm. After the polymerization there are about 2 β-CDs still entrapped on the polymeric chain through a 7 day dialyzing purification. Those threaded β-CDs are all slipped off the polymeric backbone through a further 7 day dialyzing treatment.
研究领域:
高分子化学
·
材料科学
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产品关联
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2013
·Vol. 160
·期 3
·H173
·
IF 2.588
Bin Hu,Xiaojing Lv,Jingwei Sun,Mi Ouyang,Zhiyan Fu,Cheng Zhang
In this study, a novel material, Z-2, 3-bis(4-(thiophen-3-yl)-phenyl) –acrylonitrile (Z-TPA), was synthesized and characterized. Optical and electrochromic properties of its homopolymer and copolymer with 3, 4-Ethylenedioxythiophene (EDOT) were investigated in details. UV–vis absorption and fluorescence spectra showed that this material possessed the properties of aggregation-induced emission (AIE) due to the introduction of acrylonitrile, which could show sky-blue emitting at the aggregation state and almost no emitting at the solution state. Both its polymer and copolymer displayed better redox activity. Spectroelectrochemical analysis displayed that the copolymer film exhibited multicolor showing, with a claret red in the fully reduced form and a blue-green color in the fully oxidized. Spectrochronoamperometry data revealed that the copolymer films had fast switching time and high chromatic contrast as compared to the homopolymer P(Z-TPA). What's more, the copolymer film was used to construct a dual type polymer electrochromic device (ECDs) with PEDOT. The performance of ECDs were also investigated.
研究领域:
材料科学
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光学
·
电化学
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产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 87
·70758-70765
·
IF 3.84
Leli Wang,Ying Wu,Yongjun Men,Jianan Shen,Zhengping Liu
Single electron transfer living radical polymerization (SET-LRP) was employed to prepare thermal-sensitive starch graft poly(N-isopropylacrylamide) (Starch-g-PNIPAM) with soluble Starch-Br as macro-initiator at molecular level. And Starch-g-PNIAPM with improved graft ratio and controlled length of graft chains were obtained. The effects of molar ratio of monomer to initiator and temperature on polymerization were investigated. The thermal responsibilities investigated by 1H NMR and UV showed that the LCST ranged from 31.5 °C to 23 °C with the increase of the length of PNIPAM chains and the concentrations of copolymers. Starch-g-PNIPAM hydrogels were gained when adding N,N′-methylenebisacrylamide as crosslinking agent and the swelling and deswelling behaviors were also investigated. The obtained hydrogels possess a high equilibrium swelling ratio as high as 1826%, and an extremely rapid shrinking rate as fast as losing more than 85% of water in 5 min.
研究领域:
高分子化学
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2014
·Vol. 161
·期 9
·H573
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IF 2.859
Yong Kong,Ting Zhou,Yong Qin,Yongxin Tao,Yong Wei
Graphene plays a decisive role in the electrocatalytic copolymerization of aniline and m-aminophenol. The electrochemical activity of the obtained copolymer has an improved pH dependence compared with polyaniline. The results of Fourier transform infrared spectroscopy, electrochemical quartz crystal microbalance, atomic force microscope, and ultraviolet-visible spectroscopy reveal the ion exchange behaviors of the copolymer, indicating that it could be a potential candidate for the effective electrochemical removal of toxic Cr(VI) from industrial wastewater.
研究领域:
材料科学
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环境科学
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电化学
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产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2018
·Vol. 6
·期 6
·2500-2506
·
IF 9.931
Fatang Liu,Jingchen Wang,Qinmin Pan
Excellent self-healability is considered as a critical element for next-generation flexible/wearable energy-storage devices. However, realizing superior electrochemical performances remains a big challenge for such devices because self-healability intrinsically offsets their basic energy-storage functions. Here we demonstrate that the conflict can be effectively addressed for a supercapacitor via rationally designing its device configuration at a molecular level. The capacitor is fabricated by in situ integrating polyaniline (PANI) and H2SO4 solution into a single network comprising the copolymer of vinylimidazole and hydroxypropyl acrylate (PVH). The all-in-one configuration combines fast charge-carrier transportation, good structural durability and excellent self-healability. Consequently, the resulting capacitor delivers a high specific areal capacitance and rate capability superior to its counterparts, but also maintains ultra-long cycling life even after breaking/healing 10 times. This example of configuration engineering offers a new and promising avenue to design self-healable energy-storage devices with outstanding performances.
研究领域:
材料科学
·
能源存储技术
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产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2016
·
IF 4.219
Qing Chen,Haojie Yu,Li Wang,Zain-ul Abdin,Xinpeng Yang,Junhua Wang,Weidong Zhou,Hongtao Zhang,Xiao Chen
Amylose grafted poly(acrylic acid) (Am- g -PAA) was synthesized by graft copolymerization of amylose with acrylic acid . The structure of Am- g -PAA was confirmed by 1 H NMR and FT-IR spectra. The morphology, crystallinity and thermal properties of amylose and Am- g -PAA were investigated by SEM, XRD and TGA, respectively. The highest degree of substitution (DS) of carboxyl group was 1.96 which was obtained after reacted for 1 h at 60 °C. Acrylic acid to anhydroglucose mole ratio for DS was 19.81. It was found that a large number of carboxyl groups were grafted on the backbone of amylose. It was also found that ammonia adsorption capacity of amylose increased by grafting poly(acrylic acid) on the backbone of amylose.
研究领域:
材料科学
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环境工程
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产品关联
DOI
PubMed
高影响因子
THERMOCHIMICA ACTA
·
2013
·
IF 1.989
Yanfang Liu,Jie Zhang,Chunyan Liao,Junfeng Zheng,Shasha Zhao,Mingtao Run
A copolymer of p -aminobenzonitrile type benzoxazine (BA-pabn) and diglycidyl ether of bisphenol-A (DGEBA) was prepared. With rising DGEBA content, the peak temperature of the differential scanning calorimetry curve for polymerization of BA-pabn/DGEBA blend shifts to higher value, and the roughness of the fracture surface of the BA-pabn/DGEBA copolymer increases. In the glassy state, the storage modulus of the copolymer initially tends to increase with rising DGEBA content over pure polybenzoxazine (PBA-pabn), but decreases when DGEBA content reaches to 50 wt%. The copolymer exhibits a single glass transition temperature lower than that of PBA-pabn. The onset weight loss temperature of the copolymer is higher than that of PBA-pabn, but the char yield at 800 °C is lower.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2021
·
IF 3.975
Zhitao Hu,Xiaohui Cao,Huahua Huang,Yongming Chen
Poly( ε -caprolactone) (PCL) has been one of the most important biomaterials, but its instinct hydrophobicity and slow biodegradation limit its broad applications. Herein, copolymerization of CL and a hydrophilic macrolactone, 2-oxo-15-crown-5 ether (O15C), was achieved through ring opening polymerization catalyzed by 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) using benzyl alcohol as the initiator at room temperature . A series of poly(CL- co -O15C) copolymers with different O15C contents were prepared by simply tuning the feeding ratio of [CL]/[O15C]. They showed molecular weights ranging from 11.0 to 20.6 kg mol −1 , and polydispersity index between 1.4 and 1.6, characterized by SEC (Size Exclusion Chromatography). Analysis of 1 H NMR indicated that the copolymers belong to a random copolymer structure. The introduction of O15C had a significant influence on thermal stability, hydrophilicity and degradability of the copolymers. With increasing the O15C content, the crystalline ability of PCL segment among the copolymers reduced, while the hydrophilic property was improved obviously. Through hydrolysis experiment, the poly(CL- co -O15C) with O15C content of 38 mol% exhibited a much faster degradable rate than that of the copolymer with O15C content of 10 mol%. Therefore, copolymerization of CL with a crown ether monomer via organic catalyst mediated ROP will be a feasible strategy for modification of polyester materials.
研究领域:
材料科学
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生物医学工程
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产品关联
DOI
高影响因子
Crystals
·
2022
·Vol. 12
·期 2
·210
·
IF 2.67
Xingyuan Diao,Xiaonan Chen,Shihao Deng,Hongwei Bai
Stereocomplex-type polylactide (SC-PLA) created by alternate packing of poly(L-lactide) (PLLA) and poly(D-lactide) (PDLA) chains in a crystalline state has emerged as a growingly popular engineering bioplastic that possesses excellent hydrolytic stability and thermomechanical properties. However, it is extremely difficult to acquire high-performance SC-PLA products via melt-processing of high-molecular-weight PLLA/PDLA blends because both SC crystallites and homocrystallites (HCs) are competitively formed in the melt-crystallization. Herein, a facile yet powerful way was employed to boost SC formation by introducing trace amounts of some epoxy-functionalized small-molecule modifiers into the enantiomeric blends during reactive melt-blending. The results show that the SC formation is considerably enhanced with the in situ generation of multi-arm stereo-block PLA copolymers, based on the reaction between epoxy groups of the modifiers and hydroxyl end groups of PLAs. More impressively, it is intriguing to find that the introduction of only 0.5 wt% modifiers can induce exclusive SC formation in the blends upon isothermal and non-isothermal melt-crystallizations. The outstanding SC crystallizability might be attributed to the suppressing effect of such unique copolymers on the separation of the alternately arranged PLLA/PDLA chain segments in molten state as a compatibilizer. Furthermore, the generation of these copolymers does not result in a significant increase in melt viscosity of the blends. These findings suggest new opportunities for the high-throughput processing of SC-PLA materials into useful products.Keywords:polylactide;stereocomplex;crystallization;copolymer;compatibilization
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
高影响因子
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