MOLECULES
·
2020
·Vol. 25
·期 8
·1988
·
IF 3.267
Liming He,Jun Zhou,Yutao Wang,Zhongliang Ma,Chunlin Chen
Energetic binders are a research hot-spot, and much emphasis has been placed on their mechanical properties. In this study, propargyl-terminated ethylene oxide-tetrahydrofuran copolymer (PTPET) was synthesized. Then, PTPET and low-molecular-weight ester-terminated glycidyl azide polymer (GAP) were reacted by the click reaction without using catalysts to obtain a polyether polytriazole elastomer. Through tensile tests, where R = 0.5, the tensile strength reached 0.332 MPa, with an elongation at break of 897.1%. Swelling tests were used to measure the cross-linked network and showed that the cross-linked network regularity was reduced as R increased. The same conclusions were confirmed by dynamic mechanical analysis (DMA). In DMA curves, Tg was around −70 to −65 °C, and a small amount of crystallization appeared at between −50 and −30 °C, because locally ordered structures were also present in random copolymers, thereby forming localized crystals. Their thermal performance was tested by Differential Scanning Calorimeter (DSC) and Thermal Gravimetric Analyzer (TG), and the main mass loss occurred at around 350 to 450 °C, which meant that they were stable. In conclusion, the polyether polytriazole elastomer can be used as a binder in a composite propellant.Keywords:click chemical reaction;PTPET;GAP;polytriazole;thermo-mechanical properties
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 53
·期 14
·10013-10024
·
IF 2.993
Ban Qingfu,Zhuang Qiang,Su Kehe,Wu Si,Kong Jie
The existence of toxic Cu ions in the products synthesized by Cu(I)-catalyzed azide–alkyne cycloaddition (CuAAC) click chemistry hinders biomedical applications of these products. Cu ions are difficult to remove because stable Cu(II)–triazole coordination complexes are formed in the CuAAC products. To address this problem, we demonstrate a novel interfacial liquid phase-driven method for the removal of Cu ions. We synthesized small molecules, linear polymers, and hyperbranched polymers by using CuAAC. To remove Cu ions in these products, Cu ions were precipitated using Na 2 S in a solvent mixture that contains water, dimethylformamide, and dichloromethane (DCM). The products and the CuS precipitates were automatically dispersed in the DCM phase and aqueous phase, respectively, resulting in separation of the products and CuS. Compared to the conventional Cu removal methods, our new method is highly efficient, fast, and generally applicable to small molecules and polymers. More than 98% Cu in the CuAAC products can be removed by using our method. Moreover, we tested the biocompatibility of hyperbranched polymers synthesized using CuAAC and purified using our method. These polymers are compatible to cells, indicating our Cu removal method shows promise in purification of biomaterials synthesized using CuAAC.
研究领域:
材料科学
·
生物医学工程
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高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2021
·Vol. 139
·期 12
·51842
·
IF 3.125
Kun Cong,Zhenhui Liu,Jiyu He,Rongjie Yang
Polyether polyurethane elastomers prepared by polyisocyanate N100 and ethylene oxide-tetrahydrofuran copolymer (PET) were compared to that polytriazole polyethylene oxide-tetrahydrofuran (PTPET) elastomers prepared by alkynyl-terminated polyethylene oxide-tetrahydrofuran (ATPET) and glycidyl azide polymer (GAP) at a comparative molecular weight. The polyether polyurethane (PET-N100) elastomers turned out to have better mechanical properties than that of PTPET/GAP elastomer. In order to explore the effectiveness of nitrogen-enriched structures in the field of flame-retardancy, PET-N100 and PTPET/GAP elastomers were tested by cone calorimetry. The PET-N100 elastomer exhibited an inferior performance of flame-retardancy to that of PTPET/GAP elastomer. Therefore, a modification of the terminal hydroxyl group in GAP with 4,4′-methylene-bisphenyl-isocyanate (MDI) and flame-retardant diethyl bis(2-hydroxyethyl) amino methyl phosphonate (DBMAP) was attempted and characterized by FT-IR, NMR, and gel permeation chromatography. It was found that the synthesized GAP-MDI-DBAMP could serve as a novel curing agent for ATPET, which would endow the novel PTPET elastomer a combination of the advantageous properties, that is, the outstanding mechanical properties from PET-N100 elastomer, favorable flame-retardancy from PTPET/GAP elastomer and DBAMP. The thermogravimetry analysis/DTG, DSC, tensile strength test, and swelling analysis proved that PTPET/GAP-MDI-DBAMP elastomer had excellent thermal stability and mechanical strength.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
Polymer Chemistry
·
2012
·Vol. 4
·期 5
·1396-1401
·
IF 5.321
Qiang Wang,Hongkun Li,Qiang Wei,Jing Zhi Sun,Jian Wang,Xiao A. Zhang,Anjun Qin,Ben Zhong Tang
The Cu(I)-catalyzed azide–alkyne click polymerization has become a powerful tool for the preparation of functional polytriazoles. However, copper residues in the products could harm the performance of optoelectronic devices and be cytotoxic in biological applications. The complete removal of these residues after reaction from the polymers is therefore necessary but difficult. The metal-free azide–alkyne click polymerization (MFCP) provides a solution to this problem. Currently, the MFCP is facilitated by activated alkynes, and no activated comonomer, i.e. azide, has been reported. In this paper, an activated azide, 4,4′-diazidoperfluorobenzophenone, was designed and synthesized. Compared to the ordinary azide, such a monomer can remarkably accelerate the MFCP with alkynes. Thus, a new MFCP of activated azide and alkyne was established, and polytriazoles with high regioregularity (fraction of 1,4-isomer higher than 82%) and satisfactory molecular weights (Mw up to 34 000) were produced in high yields (up to 95.1%).
研究领域:
材料科学
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化学
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR RAPID COMMUNICATIONS
·
2017
·Vol. 38
·期 17
·1700075
·
IF 4.265
Hongkun Li,Weiwen Chi,Yajing Liu,Wei Yuan,Yaowen Li,Yongfang Li,Ben Zhong Tang
Ferrocene-based polymers have drawn much attention in the past decades due to their unique properties and promising applications. However, the synthesis of hyperbranched polymers is still a great challenge. Here, two ferrocene-based hyperbranched polytriazoles with high molecular weights are facilely prepared by the click polymerization reactions of ferrocene-containing diazides ( 1 ) and tris(4-ethynylphenyl)amine ( 2 ) using Cu(PPh 3 ) 3 Br as catalyst in dimethylformamide at 60 °C for 5 and 9 h in satisfactory yields of 54.0% and 52.3%. The resulting polytriazoles are soluble in common organic solvents and thermally stable, with 5% weight loss temperatures up to 307 °C. They can be used as precursors to produce nanostructured ceramics with good magnetizability by pyrolysis at elevated temperature.
研究领域:
材料化学
·
高分子化学
·
纳米材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DESIGNED MONOMERS AND POLYMERS
·
2016
·
IF 1.497
Yangyang Wang,Liqiang Wan,Dongjing Han,Lvyuan Ye,Farong Huang
2,4,6-Tri(4-propargyloxy-phenyl)pyridine(POPP) was made from 2,4,6-tri (4-hydroxyphenyl)pyridine(HPP) and propargyl bromide. The chemical structures of POPP and HPP were well characterized by means of FTIR, 1H-NMR, 13C-NMR, and elemental analysis. Novel polytriazole resins (P-PTA resins) were prepared from POPP and azide compounds via 1, 3-dipolar cycloaddition reaction and characterized by solubility, FTIR, DSC, and TGA analyses. The P-PTA resins show good solubility in common solvents. The resins could be cured at 80 °C. The glass transition temperature (Tg) and the 5% weight loss temperature (Td5) of the cured P-PTA-33 resin arrive at 310 and 365 °C in nitrogen atmosphere, respectively.
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
危险品化学品经营许可证（带存储）