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Influence of morphology on high-temperature rheological properties of bitumen modified with styrene-butadiene-styrene

《结构与土木工程前沿（英文）》 2021年 第15卷 第3期   页码 806-819 doi: 10.1007/s11709-021-0731-y

摘要： Different microstructures of the same polymer-modified bitumen (PMB) were obtained by subjecting the bitumen modified with styrene-butadiene-styrene (SBS) copolymer to isothermal annealing at various temperatures. The effects of the morphology on the rheological properties of SBS-modified bitumen were investigated within the high-temperature range. The PMB microstructures were quantitatively evaluated using image analysis. A dynamic shear rheometer was used to measure the rheological parameters of the PMB samples and perform the multiple stress creep and recovery (MSCR) test. A quantitative basis could be established on which to discuss the relationship between the PMB morphology and rheology. The image analysis indicated that conditioning by isothermal annealing evidently led to a difference in the microstructure of the samples. Variation of the thermal history is demonstrated to be a practical way to vary the morphology of the PMB with the same raw materials and formulation. Compared with the two-phase morphology, the single-phase microstructure tended to have a narrower linear viscoelastic (LVE) region of the PMB. Within the LVE region, especially at low frequencies, the homogenous PMB can store more energy when experiencing loadings and is more elastic. Outside the LVE region, based on the MSCR test results, the homogenous morphology could assist in reaching a higher percentage of strain recovery after the creep period.

关键词： polymer     bitumen     microstructure     rheology     viscoelasticity    

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Effect of styrene-butadiene-styrene copolymer on the aging resistance of asphalt: An atomistic understanding

《结构与土木工程前沿（英文）》 2021年 第15卷 第5期   页码 1261-1276 doi: 10.1007/s11709-021-0761-5

摘要： To reveal the potential influence of styrene-butadiene-styrene (SBS) polymer modification on the anti-aging performance of asphalt, and its mechanism, we explored the aging characteristics of base asphalt and SBS-modified asphalt by reaction force field (ReaxFF) and classical molecular dynamics simulations. The results illustrate that the SBS asphalt is more susceptible to oxidative aging than the base asphalt under oxygen-deficient conditions due to the presence of unsaturated C=C bonds in the SBS polymer. In the case of sufficient oxygen, the SBS polymer inhibits the oxidation of asphalt by restraining the diffusion of asphalt molecules. Compared with the base asphalt, the SBS asphalt exhibits a higher degree of oxidation at the early stage of pavement service and a lower degree of oxidation in the long run. In addition, SBS polymer degrades into small blocks during aging, thus counteracting the hardening of aged asphalt and partially restoring its low-temperature cracking resistance.

关键词： SBS asphalt     oxidative aging     asphalt hardening     ReaxFF     molecular dynamics    

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Synthesis of a new iron (III) porphyrin acrylate-styrene copolymer and its catalysis for hydroxylation

YU Hancheng, LI Xixian, HUANG Jinwang, JI Liangnian, CHEN Xianli

《化学科学与工程前沿（英文）》 2007年 第1卷 第1期   页码 65-67 doi: 10.1007/s11705-007-0013-9

摘要： A new iron (III) porphyrin acrylate-styrene copolymer, P[(PorFe)A-S], was synthesized by the reaction of iron (III) porphyrin acrylate with styrene and characterized by UV-Vis, Infrared spectra (IR), inductively coupled plasma-atomic emission spectrometry (ICP) and molecular weight determination. Its catalytic activity in the hydroxylation of cyclohexane for model cytochrome P450 in the P[(PorFe)A-S]-O ascrobate-thiosalicylic acid system has been studied. It was found that the P[(PorFe)A-S] has a higher catalytic activity than non-supported iron (III) porphyrin and its high catalytic activity remained in reuse. The catalytic activity of P[(PorFe)A-S] was discussed in the view of the microenvironment of iron (III) porphyrin. It is proposed that the atalytic activity of the P[(PorFe)A-S] may be further enhanced by construction of a homophase catalytic system containing the iron (III) porphyrin acrylate-styrene copolymer.

关键词： plasma-atomic emission     UV-Vis     weight determination     acrylate-styrene copolymer     styrene    

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Study on the gas permeabilities in styrene-butadiene rubber by molecular dynamics simulation

Hailu LIU, Xuejia DING, Jun YI, Liqun ZHANG, Sizhu WU,

《化学科学与工程前沿（英文）》 2010年 第4卷 第3期   页码 257-262 doi: 10.1007/s11705-009-0270-x

摘要： In this research, molecular dynamics (MD)simulations were used to study the transport properties of small gas molecules in the butadiene-styrene copolymer(SBR). The condensed-phase optimized molecular potentials for atomistic simulation studies (COMPASS) force field was applied. The diffusion coefficients were obtained from MD (NVT ensemble) and the relationship between gas permeability; the chemical structure and free volume of butadiene-styrene copolymer were investigated. The results indicated that the diffusion coefficient of oxygen declined with increasing styrene content. The fraction of free volume (FFV) in butadiene-styrene copolymer was calculated. It was concluded that diffusion coefficient increased as the FFV increases, which is in accordance with the analysis of the small molecular hop through the free volume in polymer matrix. Subsequently, the glass transition temperatures of these copolymers were calculated by MD. The result showed that the glass transition temperature increased with increasing styrene content in polymer.

关键词： diffusion     atomistic simulation     permeability     chemical structure     relationship    

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Synthesis of poly(maleic acid alkylamide-

Jingjing XU, Jun XU, Jie SUN, Shili XING, Li LI, Xuhong GUO

《化学科学与工程前沿（英文）》 2011年 第5卷 第1期   页码 74-78 doi: 10.1007/s11705-010-0542-5

摘要： To improve the flow ability of crude oil with high content of aromatic asphaltenes, new comb-type copolymers of poly(maleic anhydride- - -olefin- -styrene) (MASCs) with different ratios of maleic anhydride (MA) to styrene were designed and synthesized. H NMR and FTIR spectra were used to characterize the chemical structure of the copolymers. The effect of copolymers on the flow ability of model waxy oil and crude oil were studied by rheological method and polarizing light microscopy. Upon the addition of MASCs, the yield stresses of oils were decreased by 1 to 3 orders of magnitude, and the morphology of paraffin crystals were reduced and changed from plates to needles.

关键词： comb-polymers     styrene     paraffin     crystallization     flow ability    

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Bio-based Waterborne Poly(Vanillin-Butyl Acrylate)/MXene Coatings for Leather with Desired Warmth Retention and Antibacterial Properties

Jianzhong Ma,Li Ma,Lei Zhang,Wenbo Zhang,Qianqian Fan,Buxing Han,

《工程（英文）》 doi: 10.1016/j.eng.2023.06.005

摘要： This study presents a solvent-free, facile synthesis of a bio-based green antibacterial agent and aromatic monomer methacrylated vanillin (MV) using vanillin. The resulting MV not only imparted antibacterial properties to coatings layered on leather, but could also be employed as a green alternative to petroleum-based carcinogen styrene (St). Herein, MV was copolymerized with butyl acrylate (BA) to obtain waterborne bio-based P(MV–BA) miniemulsion via miniemulsion polymerization. Subsequently, MXene nanosheets with excellent photothermal conversion performance and antibacterial properties, were introduced into the P(MV–BA) miniemulsion by ultrasonic dispersion. During the gradual solidification of P(MV–BA)/MXene nanocomposite miniemulsion on the leather surface, MXene gradually migrated to the surface of leather coatings due to the cavitation effect of ultrasonication and amphiphilicity of MXene, which prompted its full exposure to light and bacteria, exerting the maximum photothermal conversion efficiency and significant antibacterial efficacy. In particular, when the dosage of MXene nanosheets was 1.4 wt%, the surface temperature of P(MV–BA)/MXene nanocomposite miniemulsion-coated leather (PML) increased by about 15 °C in an outdoor environment during winter, and the antibacterial rate against Escherichia coli and Staphylococcus aureus was nearly 100% under the simulated sunlight treatment for 30 min. Moreover, the introduction of MXene nanosheets increased the air permeability, water vapor permeability, and thermal stability of these coatings. This study provides a new insight into the preparation of novel, green, and waterborne bio-based nanocomposite coatings for leather, with desired warmth retention and antibacterial properties. It can not only realize zero-carbon heating based on sunlight in winter, reducing the use of fossil fuels and greenhouse gas emissions, but also improve ability to fight off invasion by harmful bacteria, viruses, and other microorganisms.

关键词： MXene nanosheets     Vanillin     Styrene substitute     Leather coating     Photothermal conversion     Warmth retention     Antibacterial properties    

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标题 作者 时间 类型 操作

Influence of morphology on high-temperature rheological properties of bitumen modified with styrene-butadiene-styrene

期刊论文

Effect of styrene-butadiene-styrene copolymer on the aging resistance of asphalt: An atomistic understanding

期刊论文

Synthesis of a new iron (III) porphyrin acrylate-styrene copolymer and its catalysis for hydroxylation

YU Hancheng, LI Xixian, HUANG Jinwang, JI Liangnian, CHEN Xianli

期刊论文

Study on the gas permeabilities in styrene-butadiene rubber by molecular dynamics simulation

Hailu LIU, Xuejia DING, Jun YI, Liqun ZHANG, Sizhu WU,

期刊论文

Synthesis of poly(maleic acid alkylamide-

Jingjing XU, Jun XU, Jie SUN, Shili XING, Li LI, Xuhong GUO

期刊论文

Bio-based Waterborne Poly(Vanillin-Butyl Acrylate)/MXene Coatings for Leather with Desired Warmth Retention and Antibacterial Properties

Jianzhong Ma,Li Ma,Lei Zhang,Wenbo Zhang,Qianqian Fan,Buxing Han,

期刊论文