JOURNAL OF HAZARDOUS MATERIALS
·
2025
·
IF 11.3
Simeng Li,Xiaohui Li,Chen Zhang,Bowen Li,Peiwen Yu,Qin Dai,Hongping Wang,Fen Jin
Trisiloxane ethoxylates (TSEO n ) have been found in multiple agro-environmental media due to their pervasive application in agricultural production. While some studies suggested that the differences in the toxicological effects of TSEO n were closely related to their end-capping groups, the environmental behaviors and fate of TSEO n congeners with varying end-capping groups in agroecosystems remain underexplored. This study investigated the dissipation patterns of 39 oligomers across three TSEO n congeners in cucumber, leaves, and soils through field trials, including TSEO n -H (hydroxy, n = 2 to 14), TSEO n -CH 3 (methoxy, n = 2 to 14), and TSEO n -COCH 3 (acetoxy, n = 3 to 15). All TSEO n oligomers dissipated following pseudo-first-order kinetics in cucumber, leaves, and soils with half-lives were 2.08-3.92 d, 1.77-4.44 d, and 5.06-19.80 d, respectively. TSEO n congeners in agro-environmental media presented different dissipation patterns affected by their end-capping groups. The interfacial behaviors of TSEO n -COCH 3 in the leaves differed from those of TSEO n -H and TSEO n -CH 3 . The half-lives of TSEO n -H and TSEO n -CH 3 congeners in soils were significantly positively correlated with log K OC , indicating that long-chain congeners preferentially partition to soil solid phases, leading to slower dissipation rates than short-chain congeners. Furthermore, long-chain TSEO n congeners may dissipate to short-chain congeners. The dietary risks of ΣTSEO n -CH 3 intake through cucumber fruits were deemed safe for different Chinese populations based on the margin of exposure (MOE) assessment. This study alerts us to the environmental behaviors and fate of organosilicone surfactants and provides a baseline reference to the dietary exposure risks of TSEO n .
研究领域:
环境科学
·
农业科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER
·
2021
·
IF 4.43
Bo-Wen Liu,Yu-Fei Lei,Xiao-Feng Liu,De-Ming Guo,Li Chen,Yu-Zhong Wang
Despite the excellent overall performance, the application of polyesters is severely restricted by their inherently high flammability . Although many gratifying results have been achieved through different fire-safety methods, customization is still needed for every specific polymer, thus a generally applicable method is highly desired. Herein, we developed an eco-friendly and general fire-safety method for semi-aromatic polyesters based on the “end-group-capturing” concept. The functional monomer was chemically incorporated into the main chains of a series of semi-aromatic polyesters with similar structures (i.e., polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT) and polybutylene terephthalate (PBT)), and the specific contribution of the fire-safety method was investigated comprehensively. The results showed that the fire safety of all the copolyesters were efficiently improved, while interestingly, the fire safety gradually declined with the increase of the methylene group numbers in their molecular chains. The reason behind this phenomenon was comprehensively studied by both theoretical calculation and experiments. The increasing cyclization tendency of the copolyesters derived from the increase of the methylene group numbers was proved to be responsible for the decrease of the fire safety. The successful application and in-depth mechanism revealed here provide theoretical supports for the development of novel fire-safety polymeric materials.
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
Crystals
·
2023
·Vol. 13
·期 7
·1005
·
IF 2.7
Zhiwei Liu,Guanlong Li,Yan Zhao,Xiangbao Chen
The rapid development of electronic technology has brought convenience and efficiency to the lives of modern people, while emphasizing the need for novel materials with designability and excellent dielectric properties at the same time. In this work, Ti3C2TxMXene nanosheets (MNSs) underwent NH3·H2O solvothermal treatment at temperatures of 40 °C, 60 °C, 80 °C, 100 °C, 120 °C, 140 °C, 160 °C, and 180 °C. The changes in the surface groups and dielectric properties after the solvothermal treatment were studied. The solvothermal treatment increased the proportion of surface -OH groups, which was beneficial to the permittivity of the MNSs. However, as the treating temperature increased, the amount of -OH on the surface of the MNSs showed a reducing trend, according to XPS spectra. As the treating temperature rose from 40 °C to 80 °C, the real part of the permittivity of MNS sample showed a significant decrease, eventually remaining approximately stable in the 80 °C to 180 °C samples. The results of electromagnetic characterization were in line with the group proportion, as determined via the XPS O1s spectra, supporting the previous conclusion that the -OH group played an important role in the permittivity.Keywords:NH3·H2O solvothermal;end groups;dielectric property;2D nanosheets
研究领域:
材料科学
·
纳米技术
·
电子学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS IN CIVIL ENGINEERING
·
2024
·Vol. 37
·期 1
·04024444
·
IF 3.1
Xing Gong,Quantao Liu,Yingxue Zou,Xuefei Liu,Huan Wang,Pei Wan,Zhilong Cao,Shaopeng Wu
The poor adhesion of asphalt–granite limits the application of granite. This research aims to enhance the adhesion of asphalt and granite by establishing chemical connections between the hydroxyl groups on granite surface and the incompletely reacted isocyanate groups in polyurethane (PU) modified asphalt. For this purpose, end-capped PU modified asphalt (PUMA) was prepared, the adhesion mechanism between PUMA and granite was analyzed by Raman spectroscopy, the adhesion properties between PUMA and granite at different curing periods were evaluated by boiling and pull-out tests, and the wettability of PUMA on granite and its moisture sensitivity were evaluated using surface free energy (SFE) method. The findings suggested that the incompletely reacted isocyanate groups in PUMA can establish a chemical connection with the hydroxyl groups on the surface of granite. The adhesion between asphalt and granite can be greatly improved by the addition of PU, and this improvement is amplified as the curing time is extended. When the curing time is extended to 3 days, the fracture mode between asphalt and granite changed from adhesive failure to cohesive failure, and after 15 days of curing, the coating ratio of PUMA on granite following the water boiling test can be raised by 28.11% in comparison to the base asphalt. The water damage resistance of PUMA-granite system can be increased by adding PU and the adhesion work and combination ratio of the freshly prepared PUMA were increased by 55.91% and 79.45%, respectively, as compared to base asphalt. This study has great significance for enhancing the adhesion between asphalt and granite and encouraging granite application.
研究领域:
材料科学
·
土木工程
✓ 已验证
DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2020
·Vol. 221
·期 6
·1900557
·
IF 2.335
Yiran Wang,Xianhong Zhang,Yuhong Ma,Dong Chen,Changwen Zhao,Wantai Yang
This study reports a step-growth click-polymerization of 1,4-benzenedimethane (BDMT) and diethylene glycol divinyl ether (DEGVE) with 4-( N,N -diphenylamino)-benzaldehyde (DPAB) as a photoredox catalyst under irradiation of visible light. DPAB exhibits a strong UV–vis absorption at 350 nm and a strong fluorescence emission at 480 nm in anisole. There is a strong fluorescence quenching between BDMT and DPAB. The molecular weight of the polythiolether can be controlled by reaction time and monomer feed ratios. More importantly, α,ω-dithiol and α,ω-divinyl telechelic polythiolether oligomers are successfully synthesized by simply changing the molar ratios of BDMT to DEGVE. 1 H NMR and MALDI-TOF MS spectra demonstrate that the oligomers have high end group fidelity. In addition, strong fluorescence is observed when the α,ω-dithiol terminated polythiolether adds with N -(1-pyrenyl) maleimide, indicating that the as-prepared polythiolether bears reactive thiol end groups. Furthermore, high molecular weight polythiolether are prepared by chain extension with reactive polythiolether oligomers as macro-monomers. For example, α,ω-divinyl oligomer ( M n = 2000 g mol −1 ) could further react with α,ω-dithiol oligomer ( M n = 2400 g mol −1 ) to form high molecular weight polythiolether ( M n = 6000 g mol −1 ).
研究领域:
材料科学
·
化学工程
·
高分子化学
✓ 已验证
DOI
高影响因子
COLLOID AND POLYMER SCIENCE
·
2015
·Vol. 294
·期 1
·77-85
·
IF 1.865
Ding Guangzhu,Liu Huanyu,Jin Qianqian,Liu Jieping
The formation of micelle self-assembled from hydrophobically end-capped poly(ethylene oxide) (PEO) and its application for drug delivery have been investigated. As an important ABA-type associative triblock copolymer, a series of hydrophobically end-capped poly(ethylene oxide) [H(CH 2 ) n O(CH 2 CH 2 O) m (CH 2 ) n H], consisting of PEO (B) as hydrophilic segment and alkyl groups as hydrophobic block, are synthesized successfully according to 1 H NMR, Fourier transform infrared (FTIR), and differential scanning calorimetry (DSC) measurements. The triblock polymer is easy to form aggregates (micelles) under the appropriate conditions. The morphologies of micelles are found to be spherical confirmed by atomic force microscopy (AFM) measurement. Then, the polymeric micelles self-assembled from the triblock copolymer are used as a nanocarrier to solubilize poorly water-soluble drug spironolactone (a typical hydrophobicity drug). In vitro release behavior of spironolactone from triblock copolymer micelle is investigated carefully. It indicates interestingly that the drug can be released from triblock copolymer micelle stably and the release rate can be modulated by the variation of copolymer composition.
研究领域:
药剂学
·
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULES
·
2018
·
IF 5.914
Zhukang Du,Xiaolong Yan,Renfeng Dong,Kang Ke,Biye Ren,Zhen Tong
Telechelic associative polymers (TAPs) can form a dynamic transient network in water and have been widely used as rheological modifiers for improving solution rheological properties in many industrial fields. In this work, we designed and prepared a novel photoresponsive coumarin-functionalized telechelic associative model polymer (CouTAP), which was used to investigate the influence of light-induced dimerization of coumarin end groups on the polymer structure and solution rheological properties. The effects of light intensity, irradiation time, polymer concentration, and temperature on the transient network and rheological behavior of the CouTAP aqueous solution were studied in detail. The rheological properties of the dimerized CouTAP aqueous solution show weak temperature dependence, and the dynamics hardly depends on concentration due to the transformation of triblock to multiblock polymers. A novel transient network model composed of train loops and bridges covalently linked to train loops was proposed to describe the unique solution properties. This work will not only provide new insights into the influence of the light-induced dimerization of coumarin end groups on the network structure and rheological properties of CouTAP solution but also opens a new perspective for the controlled self-assembly of amphiphilic polymers and some special applications of TAPs in the manufacturing and transmission of soft materials, waterborne coating, inks, medicines, cosmetics, and so on.
研究领域:
高分子化学
·
材料科学
·
流变学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 35
·21780-21789
·
IF 3.108
Fuchen Zhang,Qiuxia Wang,Lipeng Wang,Yongping Bai
Herein, poly(ethylene terephthalate-co-isophthalate) (PETI) was synthesized via an ethylene glycol stibium/γ-AlOOH composite catalyst and a study was carried out on the structural changes of the end groups of poly(ethylene terephthalate-co-isophthalate) (PETI). Based on this study, the effect of the structural changes of these end groups on the crystallization and optical properties of polyester has been discussed. Moreover, it was found that after the catalytic reaction, the γ-AlOOH and the carboxyl end groups of PETI generated terminal carboxyl aluminum coordination compounds. The composite catalyst generated alkoxy aluminum and alkoxy stibium. The strong nucleating ability of these new end group structures changed the crystallization properties of the polyester. Moreover, the optical properties of the polyester were affected and as a result, a 90.46% transmittance for PETI was observed.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2014
·Vol. 5
·期 14
·4311-4320
·
IF 5.368
Liang-Wei Zhu,Bai-Heng Wu,Ling-Shu Wan,Zhi-Kang Xu
The breath figure method has emerged as a new self-assembly technique to fabricate ordered porous materials, which show potential applications in many fields, such as size-selective separation membranes. However, it is challenging to customize the structures, especially to precisely tune the pore size in a wide range. Moreover, the relationship between polymer structure and film morphologies is still unknown. In this paper, we report a facile, effective, and controllable way to manipulate the evolution of morphologies of honeycomb films, which is based on the blends of an amphiphilic block copolymer and polystyrenes with hydrophobic end groups. A series of atom transfer radical polymerization (ATRP) initiators with alkyl or fluorinated groups were synthesized for polystyrenes with hydrophobic end groups. Polymerization kinetics confirmed the viability of these ATRP initiators. Surface segregation behaviors of the hydrophobic end groups were demonstrated by measuring the surface chemical composition and surface free energies. We found that the polystyrenes with hydrophobic end groups form ordered films only at high polymer concentration (40–60 mg mL−1); moreover, the use of blends of two types of polystyrenes, one of which has a hydrophobic end group whereas the other has a hydrophilic block, can greatly increase the regularity of the honeycomb films and provide the possibility to fine-tune the pore diameter. Moreover, the evolution of surface morphologies of the films can be ideally correlated with the surface free energies of the end-functionalized polymers.
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
·
2022
·Vol. 12
·期 5
·3108-3118
·
IF 4.036
Jiayu Duan,Chen Yang,Hailan Kang,Long Li,Feng Yang,Qinghong Fang,Wenchi Han,Donghan Li
In order to design and prepare liquid fluoroelastomers with different end groups, and reveal the relationship between the molecular chain structure and properties, we studied on the oxidation degradation method and functional group conversion method to prepare carboxyl-terminated and hydroxyl-terminated liquid fluoroelastomers, respectively. The reaction mechanisms were also deduced. Furthermore, the curing system was created for liquid fluoroelastomers, and systematically analyzed their properties. The sequence type and content of the –CC– and oxygen-containing groups in the samples were measured and characterized by attenuated total reflectance/Fourier transform infrared (ATR-FTIR) spectroscopy, 1H nuclear magnetic resonance (1H-NMR), 19F-NMR spectroscopy and chemical titration, the molecular weights of liquid fluoroelastomers were measured by gel permeation chromatography (GPC). Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to examine the thermal properties, while a viscometer was used to measure the dynamic viscosity of the liquid fluoroelastomers. Then the mechanical and surface properties of the cured samples were examined by universal testing machine and contact angle measurement instrument, respectively. The results show that carboxyl-terminated liquid fluoroelastomer with 2.71 wt% carboxyl terminal groups can be prepared by oxidation degradation method. When lithium aluminium hydride (LiAlH4) was used as the reducing agent, it can efficiently convert carboxyl group to hydroxyl group with a conversion rate of more than 95%. In addition, it can be seen that the dynamic viscosity of the liquid fluoroelastomers were all decreased with the increase of temperature, and it is similar to about 10 Pa s at 70 °C. Compared with carboxyl-terminated liquid fluoroelastomers, hydroxyl-terminated liquid fluoroelastomers has higher curing reactivity, higher glass transition temperature (Tg) and thermal decomposition temperature (Td), and better mechanical properties of cured samples. The two types of liquid fluoroelastomers with distinct end groups presented distinct hydrophilicity.
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
POLYMER TESTING
·
2014
·
IF 1.816
Heng Chen,Jiqiong Jia,Wanbin Zhang,Jie Kong
In this contribution, we focused on the analysis of the topological structure of hyperbranched polymers derived from AB n (n ≥ 2) monomers . It was proved that the content of terminal groups (C T ) in hyperbranched polymers only depended on the number of B functional groups in AB n monomers ( n ) and molar mass of linear unit of A 0 B (n − 1) (M A0B(n − 1) ), regardless of the degree of branching. The C T of the hyperbranched polymers can be determined according to a simple expression: C T = (n − 1)/M A0B(n − 1) . This formula method was verified to be a simple and reliable approach, as compared to the traditional NMR or titration methods, to determine the content of terminal groups in hyperbranched polymers based on the analysis of model hyperbranched aliphatic polyesters.
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 ENGINEERING AND SCIENCE
·
2025
·
IF 3.2
Jiawei Liu,Tongjia Zhang,Lixin Song,Guangyuan Zhou,Honghua Wang
Incorporating reactive groups that can participate in epoxy cross-linking into traditional thermoplastic toughening agents enhances the interfacial compatibility between thermoplastic and thermosetting resins, thereby improving the impact toughness of the system. In this study, hydroxyl end groups were integrated into phenolphthalein polyether ketone (PEKC) molecular chains to engage in the cross-linking reaction during epoxy curing, significantly enhancing the toughening effect on the epoxy system. The results indicate that hydroxyl-terminated phenolphthalein polyether ketone (PEKC-OH) of various molecular weights can enhance the impact strength of the epoxy system (E51/MTHPA). Among these, the PEKC-OH-2 resin exhibited the optimal toughening effect at an addition level of 10 phr, increasing the impact strength from 11.85 to 23.46 kJ/m 2 , representing a 98% improvement, without compromising the operating temperature and mechanical properties of the epoxy system. Additionally, kilogram-scale toughening agent resins were produced through scale-up experiments of PEKC-OH-2 in a 50-L polymerization reactor, validating its applicability for industrial epoxy toughening. In summary, the PEKC-OH synthesized in this study serves as an efficient reactive thermoplastic toughening agent, offering ease of preparation, industrial producibility, and considerable application potential. Highlights Novel hydroxyl-terminated phenolphthalein polyether ketone (PEKC-OH). Reactive hydroxyl end groups improved compatibility with epoxy resin. PEKC-OH formed an interpenetrating network with epoxy, boosting impact toughness. Scaled-up of PEKC-OH-2 in a 50-L reactor for industrial production. PEKC-OH is feasible to prepare and has great application prospect.
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）