JOURNAL OF APPLIED POLYMER SCIENCE
·
2017
·Vol. 134
·期 26
·
IF 1.86
Fangqiao Zhao,Xiaoma Fei,Wei Wei,Weitao Ye,Jing Luo,Yaxin Chen,Ye Zhu,Xiaoya Liu
Toughening of epoxy resin by block copolymers containing an epoxy-philic block and an epoxy-phobic block is usually costly because of their complex preparation procedure. In this work, a novel, random epoxy-amphiphilic copolymer (PHGEL), which combines an “epoxy-philic” component and an “epoxy-phobic” component, has been synthesized and evaluated as a potential toughening agent for a diglycidyl ether of bisphenol A–based epoxy thermoset (EP). The curing behavior of the EP/PHGEL system has been investigated, and the results show that the hydroxyl group on the PHGEL chain can slightly activate the curing reaction. The mechanical testing shows that the toughness of the epoxy resin is improved by 294% when 4 wt % of PHGEL is added. Simultaneously, the tensile strength, elongation at break, and glass-transition temperature are also improved. In addition, the thermogravimetric analysis shows that PHGEL has no obvious effect on the thermal stability of the epoxy thermosets. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44863.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
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2021
·
IF 5.909
Hong-Fang Li,Shao-Du An,Luyun Zhang,Hui Peng,Wenzhong Ma,Xiaoyu Meng,Hai-Mu Ye
Slow-release fertilizers have been widely used to promote agricultural production with less losses to the environment. However, further achievement of fertilizer with precisely regulable release performance is still full of challenges, especially for the most used nitrogen fertilizer – urea. In this study, we provide a strategy for regulating performance of slow-release urea fertilizer (SRUF) based on inclusion complexation between biodegradable copolyester and urea via simply changing chain composition. The units of butylene adipate (BA) are copolymerized into the main chains of poly(butylene succinate) (PBS) to obtain a series of random copolyesters of poly(butylene succinate- co -butylene adipate) (PBSA). The crystallizability of PBSA declines with increasing BA content, leading to the longer slow-release time for corresponding PBSA/urea inclusion complex fertilizer. The monotonous, nearly linear relationship between chain composition and the slow-release performance of SRUF has been demonstrated, revealing the great potential to design SRUF with precise slow-release time. Consequently, pot trails in the lab are employed to evaluate the promotion effect of SRUF on Brassica chinensis L.. The growth indexes of plants significantly increase with increasing BA content in PBSA chains used in SRUF of inclusion complex. The plants reach about twice of dry weight in optimized group by referring to neat urea group when the SRUF shows a release duration closely matching to the growth cycle of Brassica chinensis L.
研究领域:
农业科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
KEY ENGINEERING MATERIALS
·
2021
·
IF 0
Yang Yi Chen,Wen Jing Wen,Zhi Qin Su,Qi Huan,Chu Yang Zhang
Thermo-responsive random copolymer poly (2-(2-methoxyethoxy) ethoxyethyl methacrylate-co-poly (ethylene glycol) methyl ether methacrylate), abbreviated as P(MEO2MA-co-OEGMA300) was synthesized by 2-(2-methoxyethoxy) ethoxyethyl methacrylate (MEO2MA) and poly (ethylene glycol) methyl ether methacrylate (OEGMA300) with a molar ratio of 1:1 via atom transfer radical polymerization (ATRP). The structure of P(MEO2MA-co-OEGMA300) was confirmed by 1H NMR and GPC. The transition behaviors of P(MEO2MA-co-OEGMA300) in aqueous solution were investigated by UV-Vis and DLS. While the transition behaviors of P(MEO2MA-co-OEGMA300) thin films were probed by white light interferometry. Compared to the P(MEO2MA-co-OEGMA300) in solution, it shows a much broader transition region, which is a promising candidate for the slow release of drug in the field of medicine.
研究领域:
材料科学
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生物医学工程
✓ 已验证
DOI
NEW JOURNAL OF CHEMISTRY
·
2024
·Vol. 48
·期 36
·16107-16118
·
IF 2.7
Zhoufeng Wang,Bolin Wang,Yingying Liu,Xiubo Long,Wenlong Yao
A series of linear block polymers and random polymers were synthesized by interfacial polycondensation using two bisphenols with similar structures, bisphenol S (BPS) and bisphenol A (BPA), and terephthaloyl chloride and isophthaloyl chloride. Random polymers and block polymers with the expected topology were structurally characterized by 1H NMR, FTIR, GPC, WAXD, and Raman spectroscopy. The results demonstrated that there was no significant difference in the thermal stability of the block and random polyarylates, which was due to the fact that the covalent bonds of the linked monomers did not change substantially, and the bond energies were the same. However, due to the alteration of the molecular sequence structure, the block polymer exhibited a lower glass transition temperature, a pronounced melting peak, and better solubility. With physical cross-linking points consisting of microcrystalline phases formed by the relatively regular molecular chain structure, the block polyarylates exhibited a higher modulus of elasticity than the random polyarylates. This illustrated that it is possible to prepare new functional polyarylates without changing the monomer composition, but only by manipulating the reaction process.
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
RSC Advances
·
2014
·Vol. 4
·期 69
·36882-36889
·
IF 3.708
Taoran Zhang,Cheng Jin,Lingyu Wang,Qinjian Yin
This article reports a facile and novel way of fabricating polymeric hollow nanospheres with azo functional groups. m-Methyl red (MMR) with a carboxyl group at the apex site could attach to random copolymer poly (acrylonitrile-stat-4-vinylpyridine) (denoted PAN-stat-P4VP), forming hydrogen-bonded brush-like polymers (HBBP) in their common solvent, tetrahydrofuran (THF). The HBBP shows unique self-assembly behavior, forming hollow nanospheres in the common solvent with increasing water content under whisking. The size and morphology of the hollow nanospheres are homogeneous and can be conveniently controlled by varying the molar ratios of the copolymers to MMR and the composition of the copolymers. DLS, TEM, SEM, FTIR and UV-vis studies demonstrated the construction and formation mechanism of the hollow nanospheres (HNSs). Compared to the conventional route to shell-cross-linked micelles and hollow spheres from the micelles composed of block copolymers, the current approach has the significant advantages of avoiding the chemical degradation of the core components and the synthesis of block copolymers. Thus, the results clearly prove that the hollow nanospheres constructed from the random copolymers and azobenzene micromolecules are a new and promising platform for the study of hollow nanospheres in solution.
研究领域:
材料科学
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化学工程
·
纳米技术
✓ 已验证
DOI
高影响因子
Polymers
·
2023
·Vol. 15
·期 13
·2812
·
IF 5
Yingwei Zhang,Chunhua Wang,Yong Yi,Wenzhi Wang,Jun Yang
In order to adjust the properties of polyamide 6 (PA6) and expand its application, a new strategy of introducing an aromatic imide structure into the PA6 chain through the random copolymerization method is reported. The diimide diacid monomer was first synthesized by the dehydration and cyclization of pyromellitic dianhydride and 6-aminocaproic acid before it reacted with 1,6-hexamethylene diamine to form poly(amide imide) (PAI) salt, and finally synthesized PA6/PAI random copolymers containing an aromatic imide structure by the random copolymerization of ε-caprolactam and PAI salt. The introduction of an aromatic imide structural unit into the PA6 chain could have a great influence on its properties. As the content of PAI increases, the crystallinity (Xc) and melting temperature (Tm) of the PA6/PAI random copolymer gradually decrease, but its glass transition temperature (Tg) increases obviously. When the PAI content is 20 wt%, the copolymer PA6/PAI-20 has the best comprehensive performance and not only has high thermal stabilities but also excellent mechanical properties (high strength, high modulus, and good toughness) and dielectric properties (low dielectric constant and dielectric loss). Moreover, these properties are significantly superior to those of PA6. Such high-performance PA6 random copolymers can provide great promise for the wider applications of PA6 materials.Keywords:polyamide 6;poly(amide imide);random copolymerization
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MACROMOLECULAR RESEARCH
·
2013
·Vol. 21
·期 12
·1338-1348
·
IF 1.639
Xu Yiting,Xie Jianjie,Chen Lingnan,Yuan Conghui,Pan Yinyin,Cheng Ling,Luo Weiang,Zeng Birong,Dai Lizong
A novel organic/inorganic hybrid amphiphilic random copolymer poly(methacrylate isobutyl POSS- co -N-isopropylacrylamide- co -oligo(ethylene glycol) methyl ether methacrylate- co -2-vinylpyridine), poly(MAPOSS- co -NIPAM- co -OEGMA- co -2VP), was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. The self-assembly behavior of random copolymers in aqueous solution was investigated by dynamic light scattering (DLS) as well as transmission electron microscopy (TEM). The results indicate the novel random copolymer in water could self-assemble into spherical aggregates and the self-aggregate size displays a remarkable dependence on pH. The stimuli-responsive characteristics of these assembles were tested by means of UV-vis spectra, DLS and TEM. There is a critic Zn 2+ concentration over which the aggregates can be coordinated into well-define spherical aggregate clusters. The critic Zn 2+ concentration can be tuned finely through adjusting solution concentration or 2VP amount. Results from UV-vis and DLS reveal that the copolymer solutions exhibit a sharp and intensive lower critical solution temperature (LCST). Some factors such as the solution concentration, molecular weight, pH and copolymer generation, which could affect the cloud point, were studied systematically. The essentially predetermined LCST can be achieved by altering the content of 2VP or pH. In addition, these novel hybrid aggregates can undergo an association/disassociation cycle with the heating and cooling of solution and the degree of reversibility shows a strong concentration dependence. As a novel organic-inorganic hybrid material which can respond to multiple external stimuli including temperature, pH, metal ions with sharp stimuli-responsive behaviors, it is potentially used for biomedicine, catalysis, diagnostics, bioseparations, biosensors and for fundamental investigation.
研究领域:
材料科学
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高分子化学
·
生物医药
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2017
·Vol. 56
·期 2
·203-212
·
IF 2.952
Hai-Chao Huang,Zong-Jun Li,Bin Wang,Xiaolu Chen,Yue-Sheng Li
A series of novel aluminum complexes containing bulky aryl-β - ketiminato ligands [ArNCH C 10 H 7 C 6 H 5 O]Al(CH 3 ) 2 ( 3a , Ar = C 6 F 5 ; 3b , Ar = C 6 H 5 ; 3c , Ar = 2,6- i Pr 2 C 6 H 3 ) have been synthesized in high yields. These complexes were identified by 1 H and 13 C NMR spectroscopy, elemental analysis, and X - ray structural analysis. All the aluminum complexes could efficiently catalyze the ROP of ɛ- caprolactone ( ɛ -CL) and Lactide (LA) in a controlled manner. It was found that the steric effect of the ligand has less effect on the ROP of CL, while the polymerization rate of L -LA was suppressed significantly. More interestingly, this kind of catalysts can promote the random copolymerization of ɛ -CL and L -LA. The transesterification side reaction and the polymer composition could be adjusted by modulating the electronic and steric effects of the ligand. In paticular, compound 3c could produce quasi-random copolymers without transesterification side reactions, as indicated by both the values of the reactivity ratios of the two monomers ( r LA = 1.31; r CL = 0.99) and the similar average lengths of the caproyl and lactidyl sequences ( L CL = 2.34; L LA = 2.44). Finally, a drug-random copolymer conjugates could be easily prepared by using 3c , indicating a potential application of 3c in pharmacutical and biomedical field. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56 , 203–212
研究领域:
高分子化学
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有机化学
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2023
·Vol. 14
·期 9
·1043-1053
·
IF 4.6
Xuejun Pan,Weiling Wu,Mo Zhu,Jixian Yang,Zhi-Chao Yan,Lianwei Li
This work reports the conformational, crystalline and rheological properties of poly(octadecyl-stat-methyl acrylate) (P(ODAx-stat-MAy)Nb) random copolymers, where Nb is the overall degree of polymerization, and x and y represent the molar fraction of ODA and MA, respectively, with x + y = 1.0. By a combination of ATRP, esterification and graft-onto strategies, a library of P(ODAx-stat-MAy)Nb samples with statistically random distribution features have been prepared. The average molar mass (M), viscometric radius (Rη) and intrinsic viscosity ([η]) are determined in solution, and a scaling-law of Rη ∼ M0.28 is established. For the conformation of P(ODAx-stat-MAy)Nb, it is found that [η] increases with x first due to chain expansion but decreases with x when x > 0.25, because the increase in segmental density dominates at high x. The rheological measurement indicates that the viscous flow activation energy remains constant first and then increases with decreasing x, reflecting the reduction of internal plasticization. In addition, the entanglement plateau modulus for the sample with x = 0.99 is one decade lower than that of the backbone, which is consistent with the prediction for the densely grafted bottlebrush polymers. This work provides a new strategy to synthesize model PODA-based random copolymers, and clarifies the change of the chain conformation, crystalline properties, and rheological behavior with the grafting density x, and this knowledge could be used to regulate the conformation and processing properties of comb/bottlebrush polymers by precisely designing the alkyl side chain's grafting density and length.
研究领域:
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2017
·
IF 3.386
Xiaodong Cai,Xiangui Yang,Hua Zhang,Gongying Wang
Aiming to improve thermal stability of poly(butylene carbonate) (PBC), a series of poly(butylene-co-1,4-cyclohexanedimethylene carbonate) (PBCCs) random copolycarbonates with weight-average molecular weights ( M w ) ranging from 1,09,000 to 1,74,000 g mol −1 and yield of 82.4to 88.4% were synthesized from Diphenyl carbonate (DPC), 1,4-butanediol (BD) and trans-1,4-cyclohexanedimethanol (CHDM) by a two-step melt polycondensation method. The structures and properties were characterized by 1 H NMR, 13 C NMR, FT-IR, GPC , WAXD , DSC , TGA , mechanical testing as well as enzymatic degradation. The results manifested that the triad components were existed in the copolymers with a random sequential structure, and incorporation of cyclohexanedimethylene carbonate (CC) units into PBC could prominently impact the thermal transition behavior, crystallinity as well as thermal stability of PBCCs in a degree. In addition, T g of PBCCs monotonously increased with the increasing CHDM content. WAXD results indicated that the CHDM introduction could obviously change the crystal structure and crystallinity of the copolymers. The thermal stability of PBCCs also expressed to be enhanced during the process of increasing CC unit content. Furthermore, the mechanical properties and biodegradability of copolymers can be easily adjusted by regulating the feed composition .
研究领域:
材料科学
·
高分子化学
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2025
·
IF 2.8
Chenglu Liang,Zhengyang Li,Yuan Chen,Yi Zhang,Yang Liu,Yukun Chen
Binders play a critical role in the preparation and operation of electrodes in lithium-ion batteries (LIBs). Developing new binding materials with high affinity to Li ions and resistance to higher voltages was desirable for the practical applications of LIBs. In this work, soluble polyimide binder (PI) with random copolymerized rigid-flexible segments were synthesized and evaluated as cathode binder for the typical lithium iron phosphate cathode material in terms of cycling performances, rate capability, and electrochemical impedance. By introducing the polar and soft ether segment into the rigid PI chains, the NMP-soluble PI precursors were obtained. The rigid-flexible segments in the PI binders work synergistically during the electrochemical process, in which the rigid segments of aromatic units with strong lithiophilic CO group provided the necessary mechanical support and affinity with electrolytes, while the flexible segments endow the high solubility and buffer effect to the volume change during the charge/discharge process. Moreover, the 3,5-diaminobenzoic acid (DABA) working as the crosslinking unit was introduced during the synthesis and the addition ratios were optimized. The as-optimized PI binders exhibited superior rate performances and comparable cycling stability when compared with the commercial PVDF binder, demonstrating the great potential for PI binder in the LIBs systems.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2014
·
IF 1.61
Xiaoqian Wang,Kewei Wang,Jie Kong,Yiguang Wang,Linan An
In this paper, we reported a novel method for synthesis of non-oxide porous ceramics by using random copolymers as precursors. A silazane oligomer and styrene monomer were used as starting materials, which were copolymerized at 120 °C to form random polysilazane–polystyrene copolymers . The copolymers were then pyrolyzed at 500 °C to obtain porous ceramics by completely decomposing polystyrene (PS) and converting polysilazane (PSZ) into non-oxide Si–C–N ceramics. The obtained material contained a bi-model pore-structure consisting of both micro-sized and nano-sized pores with very high surface area of more than 500 m 2 /g. We also demonstrated that the pore structure and surface area of the materials can be tailored by changing the ratio of the two blocks. Current results suggest a promising simple method for making multi-scaled porous non-oxide materials.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）