JOURNAL OF POLYMERS AND THE ENVIRONMENT
·
2021
·Vol. 29
·期 6
·1880-1893
·
IF 3.667
Eltayeb Mohanad,Li SanXi,Okoye Patrick U.,Wang Song
The cyclic carbonates as non-isocyanate polyurethane (NIPU) precursors are usually prepared via CO 2 fixation under harsh conditions for a satisfactory conversion rate, which is energy-intensive. Herein, cyclic carbonate was prepared under ambient conditions with high purity and yield using a water-soluble ethyl-(N′,N′dimethylamino) propylcarbodiimide hydrochloride (EDC) to provide a favored industrialization method. The glycerol carbonate was reacted with a furan-based dicarboxylic acid using EDC to evolve cyclic carbonates, followed by the aminolysis with different chemical structural amines to produce bio-based NIPUs. The effects of the reaction parameters on the yield and purity of bis(cyclic carbonate) were investigated. The results showed that the synthesized bis(cyclic carbonate) have a purity of 99% and a yield of > 70%. The different structures of the diamines exhibited different reactivity and molecular weights in the order of multi-functional amine > linear amine > cyclic amine. All the synthesized furan-based NIPUs presented excellent thermal stability above 350 °C and glass transition temperature in the range of 51.9 °C to 99.6 °C. The result demonstrates the potential of this environmentally benign strategy to prepare high-performance bio-based NIPUs with interesting properties even for biomedical applications.
研究领域:
化学工程
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材料科学
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环境科学
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DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2016
·
IF 2.196
Xiong Zheng,Ying Zhang,Maogang He,Lili Liang,Xinxin He
Fatty acid ethyl esters (FAEEs) are the main components in some biodiesels, which are important alternatives of fossil fuels. In this paper, we carry out the measurements of the speed of sound in two FAEEs at the temperatures from (293.15 to 473.15) K and at the pressures up to 10 MPa, including saturated liquid and compressed liquid. The relative expanded uncertainty in the speed of sound is estimated to be less than 1.0% with coverage factor of k to be 2. The data in saturated liquid and compressed liquid are fitted into polynomials. For saturated liquid, the D AAD is 0.16% for ethyl hexanoate and 0.09% for ethyl octanoate. For compressed liquid, the D AAD is 0.31% for ethyl hexanoate and 0.16% for ethyl octanoate. The data were also used to assess the predictive ability of Wada’s model.
研究领域:
化学工程
·
能源科学
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产品关联
DOI
高影响因子
COLLOID AND POLYMER SCIENCE
·
2017
·Vol. 295
·期 12
·2299-2307
·
IF 1.723
Ma Le,Song Lina,Li Fang,Wang Heng,Liu Baohua
Waterborne polyurethane-acrylate (WPUA) composite emulsion based on waterborne polyurethane (WPU) was prepared by sequential polymerization with methyl methacrylate (MMA) and butyl acrylate (BA). WPU was synthesized to form seed emulsion dispersion using poly (propylene carbonate) (PPC) diol as soft segment. Polyacrylate (PA) content and MMA/BA mass ratio were varied to investigate the influence on performance properties. The emulsions were characterized by evaluating the particle size, stability, and appearance. The WPUA films were characterized by FT-IR and TGA. The tensile properties, hardness, surface hydrophilicity, and coating adhesion of film were also tested. The incorporation of PA in PPC-based WPU improved the adhesion, pencil hardness, water resistance, and hydrophilicity. With the increase of PA content, the tensile strength increased initially and then decreased, while the elongation at break and toughness decreased. The experimental results indicated good compatibility and synergistic effect between PPC-based WPU and PA, which resulted in a remarkable improvement in thermal properties, adhesion, and pencil hardness.
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 Cleaner Production
·
2022
·
IF 11.072
Qin Chen,Zhen Xu,Zongxing Sun,Yanjun Sun,Jixuan Song,Xiao Zhang,Siqi Huan,Long Bai,Jiyou Gu
Petroleum-derived polyurethane using isocyanates by solvent-based processing causes undesired environmental pollution and health effects. Waterborne polyurethane is an alternative to solve this issue, however, they are inefficient as additives and inconvenient for transportation and usage owing to the large amount of water. Herein, water-processable polymethylene polyphenyl polyisocyanate (PAPI, referred as pMDI) powder modified by biobased castor oil is developed. The preparation of pMDI powder is characterized by its appearance, content of –NCO groups, and storage life. The protective mechanism of –NCO groups is explored by a battery of techniques, including microscopies, FTIR, TGA , DSC and reaction kinetics. The optimal formulation for powdered pMDI uses 0.6 wt% SDS prior to de-hydration, which retains a high level of residual –NCO groups up to two-week storage. The formation of polyurea shells covering pMDI powder upon water-processing minimizes contact and interaction between –NCO and moisture in air, blocking consumption of –NCO groups. The pMDI powder can be used as a crosslinking agent for waterborne wood adhesives, showing great bonding performances, particularly improving wet strength (0.84 MPa) at 18 wt% loading level. This strategy offers a simple, green, and cost-effective route to engineer hazardous, high-risk liquid isocyanates into environmentally-friendly, low-risk, and versatile water-processable materials that are suitable as waterborne additives.
研究领域:
材料科学
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环境科学
·
化学工程
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产品关联
DOI
高影响因子
TOXICOLOGY AND APPLIED PHARMACOLOGY
·
2023
·
IF 3.8
Jia-min Gong,Xiao-lei Yi,Jia-hong Liang,Zhen-zhong Liu,Zuo Du
Phthalate esters (PAEs), accompanied by phthalate monoesters as hydrolysis metabolites in humans, have been widely used as plasticizers and exhibited disruptive effects on the endocrine and metabolic systems. The present study aims to investigate the inhibition behavior of PAEs and phthalate monoesters on the activity of the important hydrolytic enzymes , carboxylesterases (CESs), to elucidate the toxicity mechanism from a new perspective. The results showed significant inhibition on CES1 and CES2 by most PAEs, but not by phthalate monoesters, above which the activity of CES1 was strongly inhibited by DCHP, DEHP, DiOP, DiPP, DNP, DPP and BBZP, with inhibition ratios exceeding 80%. Kinetic analyses and in vitro-in vivo extrapolation were conducted, revealing that PAEs have the potential to disrupt the metabolism of endogenous substances catalyzed by CES1 in vivo . Molecular docking results revealed that hydrogen bonds and hydrophobic contacts formed by ester bonds contributed to the interaction of PAEs towards CES1. These findings will be beneficial for understanding the adverse effect of PAEs and phthalate monoesters.
研究领域:
生物化学
·
毒理学
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产品关联
DOI
PubMed
高影响因子
EUROPEAN POLYMER JOURNAL
·
2018
·
IF 3.741
Wu Xiaomeng,Chen Xiaoyu,Fan Zhongyong
The macroinitiator of poly(1,3-trimethylene carbonate- ran -glycolide) (P(TMC- ran -GA)) copolymers terminated with hydroxyl groups were synthesized by ring-opening polymerization (ROP) at 120 °C for 12 h. Then, the novel block copolymers consisting of P(TMC- ran -GA) segments bonding with L -lactide ( L LA) and glycolide (GA) random copolymerization segments were prepared. The poly(TMC/GA- block - L LA/GA)) block copolymers were synthesized by ROP in bulk at 130 °C with high M n ¯ (above 2.0 × 10 5 Da). Such kind of block copolymers composed of P(TMC- ran -GA) and P( L LA- ran -GA) segments show good mechanical properties and adjustable degradation rate. The molecular structures of block copolymers were characterized by GPC, FTIR, and 1 H NMR. Chain microstructure analysis was performed in detail with 13 C NMR spectroscopy. The effect of GA units content on thermal behaviors, mechanical properties as well as biodegradability of copolymers was investigated by DSC, XRD, stress-strain measurements and enzymatic degradation tested in comparison with corresponding block copolymers P(TMC- block - L LA/GA). The results shown that amorphous P(TMC- ran -GA) segments significantly improve the flexibility of block copolymers. The incorporation of GA units strongly decreases the crystallization ability of L LA segment within copolymers due to more random L LA-GA sequence and shorter average L LA block length. Meanwhile, the tensile strength of material and flexibility are significantly improved with the raising GA units content. The enzymatic degradation rate is also accelerated with the increase GA unit content. Thus, the biodegradable block copolymers with unique molecular structure and modifiable properties are promising new materials for biomedical applications.
研究领域:
生物材料学
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高分子化学
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生物医学工程
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产品关联
DOI
高影响因子
Coatings
·
2022
·Vol. 12
·期 8
·1135
·
IF 3.236
Qinghong Luo,Xinyu Wen,Ruijie Xu,Zhu Liu,Hongping Xiang,Zhiquan Li,Xiaoxuan Liu
A series of novel modified waterborne polyurethane acrylate (WPU-EA) emulsions were prepared with isophorone diisocyanate (IPDI), polycarbonate diol, 2,2-bis-hydroxymethyl-propionic acid (DMPA), 1,4-butanediol (BDO), epoxy acrylate (EA), and pentaerythritol triacrylate (PETA). The structure of WPU-EA was confirmed by FTIR and1H NMR spectroscopy. The effects of different dosages of epoxy acrylate on the cured film were investigated by tensile properties, dynamic mechanical analysis and thermogravimetric analysis. The results indicate that with increasing content of epoxy acrylate, the average particle size of the emulsion gradually increases. With the rise in epoxy acrylate concentration from 0%, 3.0%, 6.0% to 9.0%, the gel fraction of the cured film increases from 83.7%, 92.5%, 93.0% to 93.6%, respectively, and the glass transition temperature rises from 90.3 °C, 107.5 °C, 141.9 °C to 146.6 °C. The tensile strength and the thermal stability of the cured film increases, and the elongation at break decreases. Moreover, the WPU-EA emulsions were sprayed on polycarbonate sheets and exhibited the advantages of high hardness, better gloss and good adhesion, which is promising for the application of plastic coatings.Keywords:UV-curing;epoxy-modified polyurethane acrylate;plastic coatings
研究领域:
材料科学
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高分子化学
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涂料技术
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产品关联
DOI
高影响因子
eFood
·
2022
·
IF 0
Wenqi Huang,Qingying Fang,Linlin Fan,Tao Hong,Huizi Tan,Shaoping Nie
Pectin with various degrees of esterification (DE) leads to different food processing directions and has the distinct potential for modulating human health. Investigations of pectin–gut microbiota interactions may contribute towards better understanding of the structure–function mechanism. In this study, in vitro batch fermentation (artificial colon model) was used to illustrate the differential impacts of pectin with different DE on the gut microbiota and metabolome of healthy adults. The results indicated that low-esterified pectin L13 showed better-sustained abilities in terms of the diversity of microbiota and promoted the abundance of Clostridiaceae and Lachnospiraceae at family levels, and Bacteroides and Lachnospira at genus levels. High-esterified pectin H121 induced less Enterococcus and Clostridium . Data from untargeted metabolomics revealed the alterations of intracellular metabolites including fatty acids, amino acids, and organic molecules by various types of pectins. Inositol was the unique intracellular metabolite that was significantly upregulated by low-esterified pectin L13. All types of pectins could increase the level of acetic acid, but butyric acid was only enriched by pectin L13.
研究领域:
食品科学
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微生物学
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代谢组学
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DOI
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·Vol. 142
·期 2
·e56337
·
IF 2.7
ZiXuan Wang,Hao Zheng,Zhengchun Cai,Haian Xia
Bio-based plastics have received much attraction because they are an alternative to petroleum-based plastics in recent years. Among them, aliphatic polyesters have garnered the most attention due to their excellent properties. Polyester is primarily synthesized through ring opening polymerization of monomer, and the catalysts used are mostly synthesized through “click” reaction in the laboratory, which exhibits inferior activity and little commercial value. Herein, a facile approach was developed for the synthesis of high molecular-weight cyclic aliphatic polyesters, specifically poly(valerolactone- co -caprolactone) with varying compositions. This involved the ring-opening copolymerization of ε-caprolactone (ε-CL) and δ-valerolactone (δ-VL) in the absence of an initiator with commercial hydrogen bond donor triclorocarban and an organic base. The structure and properties of the prepared cyclic polyester were investigated using GPC, 13 C NMR, 1 H NMR, MALDI-TOF mass spectrometry, TOF-SIMS mass spectrometry, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and X-ray diffraction (XRD) techniques. The results show that the molecular weight of cyclic polyester can rapidly exceed 40 kDa, with a PDI of approximately 1.10. In comparison to linear polyester, it has a higher melting point and superior thermodynamic properties, thus presenting greater application potential. Finally, based on nuclear magnetic resonance titration, the potential catalytic processes and mechanisms of bimolecular systems on monomers in different environments were discussed. This study not only offers new insights into the structure and properties of cyclic polyesters, but also presents novel bimolecular catalytic systems using commercial urea hydrogen bond donors for the synthesis of cyclic polymer polyesters.
研究领域:
材料科学
·
有机化学
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产品关联
DOI
高影响因子
POLYMER TESTING
·
2020
·
IF 3.275
Lidong Feng,Sheng Xiang,Yanlong Liu,Xinchao Bian,Gao Li,Xuesi Chen
An analytical method was developed to quantitatively determine residual monomers, namely, lactide (LA) and ε -caprolactone (CL), in poly(lactide- co - ε -caprolactone) (PLCL) using an internal-standard method of gas chromatography (GC). PLCL and diphenyl ether (DPE) as an internal standard were initially dissolved in dichloromethane (DCM), and then PLCL was precipitated in cyclohexane. The residual LA and CL monomers in PLCL, as well as DPE, were extracted into cyclohexane from the polymer solution. The resulting solution was directly injected into a GC system. This method was practical for measuring the residual LA and CL contents in PLCL. The relative standard deviation ( RSD ) ( n = 5) denoting the repeatability of this method was less than 5.6% and 4.3% for the LA and CL measurements, respectively, indicating that the method was sufficiently precise. The recovery rate of standard addition was 96.5%–101.5% and 98.4%–104.2% for the determination of LA and CL in PLCL, respectively. The RSD of the recovery of standard addition ( n = 5) was not more than 2.0%, indicating that the method was sufficiently accurate.
研究领域:
分析化学
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高分子材料科学
·
医学材料
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产品关联
DOI
高影响因子
Journal of Materials Chemistry B
·
2013
·Vol. 1
·期 24
·3099-3106
·
IF 0
Chunfeng Ma,Liguo Xu,Wentao Xu,Guangzhao Zhang
Degradable polyurethane (PU) with copolyester oligomer consisting of ε-caprolactone (CL) and glycolide (GA) as the soft segments has been prepared by a combination of ring-opening polymerization and condensation reaction. Enzymatic and hydrolytic degradation experiments demonstrate that the PU can degrade in seawater. Such a polyurethane exhibit a more rapid degradation in comparison with that with poly(ε-caprolactone) (PCL) soft segments because the introduction of GA can reduce the crystallinity, as revealed by differential scanning calorimetry (DSC) and polarizing optical microscope (POM). Marine field tests show that the degradable polyurethane has good antifouling ability due to its self-renewal property. Besides, such polyurethane can serve as a carrier and controlled release system for an antifoulant, and the incorporation of an antifoulant in the polyurethane can significantly improve the antifouling ability and duration.
研究领域:
材料科学
·
海洋生物学
·
生物医学工程
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产品关联
DOI
PubMed
ACS Omega
·
2017
·
IF 0
Weikeng Luo,Jiaxiang Qin,Min Xiao,Dongmei Han,Shuanjin Wang,Yuezhong Meng
High-molecular-weight poly(propylene carbonate) (PPC) [number-average molecular mass (Mn): 80 000–100 000] is readily alcoholized into PPC macrodiols in the presence of 1,2-propanediol (PDO), 1,4-butanediol (BDO), or 1,6-hexanediol (HDO). The high-molecular-weight PPC and small amount of diols, such as PDO, BDO, or HDO, were stirred at elevated temperatures to convert the extremely viscous high-molecular-weight polymer to low-molecular-weight macrodiols with gel permeation chromatography-measured Mn of about 3000 Da. The chopping reaction of the high-molecular-weight PPC was studied in detail, such as the influences of the catalyst residue, the kinds of alcoholysis agents, reaction temperature, and time. The reaction mechanism of alcoholysis is proposed according to the experimental results. The results indicate that the presence of a trace residue of zinc catalyst (Zn-G-III) in PPC, excess diol feeding, and higher temperature can accelerate the alcoholysis. Moreover, different diols can produce different PPC macrodiols with varying end-capping. Finally, polycarbonate ether urethane can be successfully synthesized using as-synthesized PPC macrodiols and poly(propylene glycol) (Mn ≈ 3000) as the soft segment and 4,4′-diphenylmethane diisocyanate or BDO as the hard segment. The full evaluation for the synthesized PPC macrodiols demonstrates their potential applications in the polyurethane industry.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
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