INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2017
·
IF 2.843
Tao Li,Jun Xu,Run Zou,Hejian Jiang,Junyou Wang,Li Li,Martien A. Cohen Stuart,Robert K. Prud’homme,Xuhong Guo
Waxy crude oil containing large amounts of paraffins often results in various difficulties in extraction and transportation, especially at low temperature. Comb-type copolymers with phenyl pendants were found to be able to improve the flow ability of waxy oils effectively. To investigate the influence of spacer length between phenyl pendant and polymer backbone in comb copolymers on the flow ability of waxy oil, poly(α-octadecene-co-maleic acid phenyl alkyl amide)s with various spacer lengths were synthesized by modification of poly(α-octadecene-co-maleic anhydride) with aniline, phenethylamine, phentermine, and phenyl-undecanoicamide. Their effects on the morphology and crystallization of model and crude oils were observed by polarized light microscopy and DSC. The flow ability of both oils in the presence of copolymers was studied by means of rheology, including measuring yield stress, viscosity, and thixotropic properties. It is found that the spacer length remarkably affects the rheology and wax crystallization behaviors for both oils. The copolymer with a longer spacer can provide better flexibility of phenyl pendants to disperse asphaltenes more effectively, and the long spacer can cocrystallize with long-chain paraffins.
研究领域:
石油工程
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高分子化学
✓ 已验证
DOI
高影响因子
HIGH PERFORMANCE POLYMERS
·
2017
·
IF 1.179
Guangliang Song,Lina Wang,Dandan Liu,Jianan Yao,Yiming Cao
Polyimides (PIs) with single phenyl pendant substitution were prepared based on three diamines containing phenyl pendant group, namely, 2,5-bis(4-aminophenoxy) biphenyl, 2-phenyl-4,4′-diaminodiphenyl ether, and 2,5-diaminobiphenyl (p-PDA), with the dianhydride component of 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and 3,3′,4,4′-biphenyltetracarboxylic dianhydride, respectively. The physical properties of the membranes were examined, including thermal properties, fractional free volume (FFV), solubility, and morphological structures, and were compared with the analogues without phenyl pendant. Gas transport properties of the membranes were investigated and discussed from the viewpoint of structure–property relationship. For 6FDA-derived PI membranes, gas permeability increased as the degree of PI backbone rigidity leveled up. Gas transport properties were not improved by the incorporation of phenyl pendant group for 6FDA type containing ether linkage and marginally improved as compared between PI (6FDA/p-PDA) and PI (6FDA/p-phenylenediamine (PDA)). To increase the phenyl substitution density of 6FDA/PDA-type backbone, a novel diamine bearing two phenyl pendant groups, that is, 2,6-diphenyl-1,4-diaminobenzene (p, p′-PDA) was synthesized, and PI derived from 6FDA and p, p′-PDA was prepared. The gas permeability coefficients of PI (6FDA/p, p′-PDA) were remarkably larger than those of PI (6FDA/p-PDA) and PI (6FDA/PDA).
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2018
·Vol. 36
·期 8
·960-969
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IF 2.016
Han Xiang-Hui,Yang Xi-Wen,Chen Sheng,Luo Hang,Zhang Dou,Zhang Hai-Liang
Long-alkyl tail triphenylene (TP) side-chain liquid crystalline polymers (SCLCPs) with different spacer length (P- m -TP, m = 2, 3, 4, 6, 8, which is the number of carbon atom in the flexible alkyl spacers) have been successfully synthesized via free radical polymerization. The differential scanning calorimetry (DSC), polarized light microscopy (POM), ultraviolet-visible spectroscopy (UV-Vis), wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS) measurements were performed to investigate the influence of multiple effects on the self-organization behaviors of P- m -TP, including steric effect, decoupling effect and π - π stacking effect. The experimental results revealed that P- m -TP ( m = 2, 3, 4) formed the columnar phase which was developed by the TP moieties and the main chain as a whole, suggesting that the side-chains had strong steric effect even though the number of spacer length ( m ) exceeded 4. In addition, the clearing points ( T i s) of the polymers were above 300 °C. When m = 6 and 8, the polymers displayed hexagonal columnar phase and exhibited the low T i s (91 and 80 °C respectively), originating from the self-assembly of triphenylene due to the decoupling effect and π - π stacking effect. This work offers a viable and inspiring pathway to control the phase transition temperature and phase structure of TP SCLCPs via simply tailoring the spacer length and increasing the alkyl tail length of TP.
研究领域:
材料科学
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
HIGH PERFORMANCE POLYMERS
·
2020
·
IF 1.568
Yan Chen,Fajian Ren,Jian gang Dai,Dongmei Li,Shajie Luo
A series of modified poly(ether ether ketone)s containing different content of benzene pendant group in the molecular chain have been successfully synthesized with 1,1-bis(4-hydroxyphenyl)-1-phenylethane, bisphenol A and 4,4′-difluorobenzophenone by nucleophilic substitution. The inherent viscosities of obtained polymers were in the range of 0.261–0.889 dLg−1. They were found to have high glass transition temperatures (Tg) of 150–168°C and 148–169°C (examined by DSC and DMA, respectively), good thermal stability with 5% weight-loss temperature (T5%) of 439–469°C. The tensile strengths of the obtained polymers were 67.7–86.6 MPa, and the storage modulus was over 0.9 GPa at about 140°C. The modified poly(ether ether ketone)s showed the excellent solubility property, they could be processed by solution method. Additionally, the obtained polymers had good optical transmittance (>70%) at 400 nm, suggesting that they have potential to be applied to the heat-resistant optical films.
研究领域:
材料科学
·
高分子化学
·
光学材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）