POLYMERS FOR ADVANCED TECHNOLOGIES
·
2019
·Vol. 31
·期 2
·260-272
·
IF 2.162
Lichen Zhang,Deqi Yi,Jianwei Hao
Poly (diallyldimethylammonium chloride) (PDDA) and ammonium polyphosphate (APP) deionized chloride ions and ammonium ions by ionizing in aqueous solution respectively, then combined to form poly (diallyldimethylammonium) and polyphosphate (PAPP) polyelectrolyte complexes as an all-in-one flame retardant for polypropylene and its composites were characterized by Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy. One flame retardant system composed of PAPP and PP, the other flame retardant system composed of PAPP, Polyamide-6 (PA6) and PP were tested by limiting oxygen index (LOI), UL-94, cone calorimeter tests and thermogravimetric analysis (TGA) and compared with pure PP. The results showed that the LOI value of PP/PAPP composite can reach 27.5%, and UL-94 V-2 rating can be reached at 25 wt% PAPP loading. Meanwhile the cone calorimetry results displayed that the peak heat release rate (PHRR) and total heat release (THR) were reduced up to 69.3% and 22.5%, respectively, compared with those of pure PP. After adding 5 wt% PA6, the carbon source missing due to the early PAPP decomposition can be made up, and PHRR and THR can be further reduced slightly. The flame retardant mechanism of PAPP was studied by FTIR spectroscopy and X-ray photoelectron spectroscopy. Six-membered ring of C─N containing conjugate double bonds, cross-linked phosphate structure formed stable, intumescent, compact char layer which greatly improved the flame retardancy of PP.
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高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2019
·Vol. 31
·期 3
·461-471
·
IF 2.162
Zhongying Yao,Lijun Qian,Yong Qiu,Yajun Chen,Bo Xu,Jie Li
Based on bio-based furfural, a phosphorus-containing curing agent (FPD) was successfully synthesized, via the addition reaction between 9,10-dihydro-9-oxa-10 phosphaphenanthrene-10-oxide (DOPO) and furfural-derived Schiff base. Then, as co-curing agent, FPD was used to prepare flame retardant epoxy thermosets (EP) cured by 4, 4′-diaminodiphenyl methane. The incorporated FPD improved the flame retardancy and toughness of epoxy thermoset, simultaneously. When 5 wt% FPD was added into EP, the FPD/EP achieved 35.7% limited oxygen index (LOI) value and passed UL94 V-0 rating, meanwhile. In FPD/EP thermoset, the incorporated FPD reduced the thermal decomposition rate, increased the charring capacity, and inhibited the combustion intensity of epoxy thermoset. Through gas-phase and condensed-phase actions in weakening fuel supply, suppressing volatile combustion, and enhancing charring barrier effect, FPD decreased the heat release of burning epoxy thermoset, significantly. For the outstanding effectiveness on both flame retardancy and toughness, the study on FPD provides a promising way to manufacture high-performance epoxy thermoset.
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高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2019
·Vol. 31
·期 3
·527-535
·
IF 2.162
Yawen Zheng,Xiaoyun Wang,Guangshun Wu
In the present research, a multifunctional hierarchical reinforcement was prepared by chemical modification of carbon fibers (CFs) with halloysite nanotubes (HNTs) by the bridging diethylenetriaminepentaacetic acid (DTPA) for improving interfacial microstructures and properties of composites. Surface structures and groups of modified HNTs and CFs were characterized systematically. The uniform distributions of the introduced DTPA and HNTs helped to increase fiber polarity, surface energy, and wettability. As a consequence, significant enhancements of interfacial properties and hydrothermal aging resistance of composites were achieved, and interfacial reinforcing mechanisms have also been studied. Moreover, the storage modulus showed a 17.95% improvement, and the glass transition temperature was enhanced by 17°C by dynamic mechanical analysis testing.
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高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2020
·Vol. 31
·期 4
·665-674
·
IF 2.578
Xiang Liu,Pengyu Feng,Lei Zhang,Yonggang Chen
Nanofiltration (NF) membranes have been widely used for the treatment of electroplating, aerospace, textile, pharmaceutical, and other chemical industries. In this work, halloysite nanotubes (HNTs) were directly anchored on the surface of commercial nanofiltration (NF) membrane by dopamine modification following advantageous bio-inspired methods. SEM and AFM images were used to characterize the HNTs decorated membrane surface in terms of surface morphology and roughness. Water contact angle (WCA) was employed in evidencing the incorporation of HNTs and dopamine in terms of hydrophilicity or hydrophobicity. Augmentation of HNTs was found to obviously enhance the hydrophilicity and surface roughness resulting in improved water permeability of membrane. More importantly, the rejection ratios of membrane also increased during the removal of heavy metal ions from wastewater. The permeability and Cu 2+ rejection ratio of modified NF membrane were as high as 13.9 L·m −2 ·h −1 ·bar −1 and 74.3%, respectively. Incorporation of HNTs was also found to enhance the anti-fouling property and stability of membrane as evident from long-term performance tests. The relative concentration of HNTs and dopamine on membrane surface was optimized by investigating the trade-off between water permeability and rejection ratio.
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高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2020
·Vol. 31
·期 5
·1099-1109
·
IF 2.578
Congrui Qi,Bihe Yuan,Haoran Dong,Kaiyuan Li,Sheng Shang,Yaru Sun,Gongqing Chen,Yuanyuan Zhan
In order to improve its water resistance and compatibility with polymer matrix, ammonium polyphosphate (APP) is modified with melamine-trimesic acid (MEL-TA) aggregates by supramolecular self-assembly technology. Chemical structure and morphology of APP@MEL-TA are investigated by Fourier transform infrared spectroscopy and scanning electron microscopy (SEM), respectively. Intumescent flame retardant system of APP@MEL-TA and charring-foaming agent is introduced into polypropylene (PP) matrix. The flammability and combustion behavior of PP composites are investigated by limiting oxygen index (LOI), UL-94 vertical burning, and cone calorimetry tests. In terms of LOI values and cone combustion results, APP@MEL-TA performs better than pristine APP. Char residue of PP composites is investigated by SEM and Raman spectra. Flame retardant mechanisms are proposed based on thermal decomposition, combustion results, and analysis on char residue.
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高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2019
·Vol. 31
·期 5
·1059-1066
·
IF 2.162
Shaohua Wen,Yongfei Li
Biodegradable polylactide (PLA) and its copolymers with shape memory properties have attracted great interests because of their important application prospects in biomedical field. In this study, random poly(L-lactide-co-trimethylene carbonate-co-ε-caprolactone) (LTCL) terpolymers with different molar ratio were synthesized and characterized. Monomer ε-caprolactone (ε-CL) was used in this study instead of glycolide in preliminary study of LTG terpolymers to investigate the transition temperature and the shape memory performance. Characterization on crystallization, mechanical properties, shape fixing, and recovery ratios of the terpolymers was conducted to investigate the correlation between crystallization and shape memory performance of LTCL terpolymers. The results are consistent with the formation of crystallized LLA segments, which could act as crosslinks, strengthened the stationary phase within the polymer matrix, and significantly improved the shape memory performance of LTCL terpolymers. For example, LTCL801010 is a crystalline polymer with high shape fixity and shape recovery ratio; its shape recovery temperature is 39°C. LTCL terpolymers with high CL content do not show shape memory performance for the rubbery at room temperature. Based on this study, PLA materials with shape memory property can be designed through the selection of monomers or the adjustment of comonomer ratio. These polymers with recovery temperature close to 37°C are expected to be used in human body such as scaffolds in tissue engineering.
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高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2019
·Vol. 31
·期 4
·807-816
·
IF 2.162
Chun-Hui Du,Xin-Yi Zhang,Chun-Jin Wu
Chitosan (CS) with good hydrophilicity and charged property was used to modify graphene oxide (GO), the obtained GO-CS was used as a novel modifier to fabricate thin film composite forward osmosis (FO) membranes. The results revealed that the amino groups on CS reacted with carboxyl groups on GO, and the lamellar structure of the GO nanosheets was peeled off by CS, resulting in the reducing of their thicknesses. The GO-CS improved the hydrophilicity of polyethersulfone (PES) substrate, and their contact angles decreased to 64° with the addition of GO-CS in the substrate. GO-CS also increased the porosity of the substrate and surface roughness of FO membrane, thereby optimizing the water flux and reverse salt flux of FO membrane. The average water flux of the FO membrane reached the optimal flux of 21.34 L/(m 2 h) when GO-CS addition was 0.5 wt%, and further addition of GO-CS to the substrate would decrease the water flux of FO membrane, and the reverse salt flux also decreased to the lowest value of 2.26 g/(m 2 h). However, the salt rejection of the membrane increased from 91.4% to 95.1% when GO-CS addition increased from 0.5 to 1.0 wt% under FO mode using 1 mol/L sodium chloride (NaCl) solution as draw solution (DS). In addition, high osmotic pressure favored water permeation, and at the same concentration of DS, magnesium chloride (MgCl 2 ) exhibited better properties than NaCl. These results all suggested that GO-CS was a good modifier to fabricate FO membrane, and MgCl 2 was a good DS candidate.
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高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2019
·Vol. 30
·期 9
·2340-2352
·
IF 2.162
Yuhui Feng,Li Yuan,Guozheng Liang,Aijuan Gu
Establishing a phosphorus-free strategy to fabricate high-performance thermosetting resins owning outstanding thermal resistance, good flame retardancy, and smoke suppression is important for sustainable development. Herein, a unique phosphorus-free hybrid (BN@CeO 2 ) was synthesized through chemically grafting cerium oxide (CeO 2 ) on surface of exfoliated boron nitride (BN) nanosheet with the aids of γ-aminopropyltriethoxysilane and polydopamine coating, which was then embedded into bisphenol A cyanate ester (BCy) resin to fabricate new BN@CeO 2 /BCy composites with high thermal resistance. Compared with BCy resin, the BN@CeO 2 /BCy composite with 4 wt% BN@CeO 2 not only has delayed initial ignition time by 23 seconds but also severally shows 58.1%, 23.1%, and 44.4% lower smoke produce rate, total heat release, and peak heat release rate. The study on mechanism behind outstanding flame retardancy reveals that the improved heat resistance and flame retardancy of BN@CeO 2 /BCy composite are attributed to multiply effects induced by BN@CeO 2 and its interaction with BCy resin; specifically, these effects come from BN (physical barrier) and CeO 2 (free radical trapping effect and catalytic char layer formation) as well as those from the synergistic effect of BN and CeO 2 . These excellent comprehensive properties of BN@CeO 2 /BCy composites demonstrate that BN@CeO 2 is an environment-friendly and synergistic modifier for developing heat-resisting thermosetting resins with outstanding flame retardancy and smoke suppression.
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高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2019
·Vol. 30
·期 9
·2331-2339
·
IF 2.162
Hao Tang,ZongMin Zhu,Rui Chen,JunJie Wang,Hong Zhou
A novel DOPO-based pyrazine derivative 6-((2-hydroxyphenyl)(pyrazin-2-ylamino)methyl)dibenzo[c,e][1,2]oxaphosphinine 6-oxide (DHBAP) was triumphantly synthesized by a two-step addition reaction using 2-aminopyrazine, 2-hydroxybenzaldehyde and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) as reactants, and characterized by Fourier-transform infrared (FTIR), 31 P nuclear magnetic resonance (NMR) and 1 H NMR. Afterwards, the addition type flame retardant (DHBAP) was utilized to modify epoxy resin (EP) by blending method. When the content of DHBAP in neat EP was 8 wt%, it reached to the V-0 rating and the limited oxygen index (LOI) value up to 34.0%. Furthermore, according to the cone calorimeter (CC) test results, the heat release rate (HRR), total heat release (THR), smoke produce rate (SPR) and total smoke production (TSP) of EP/8% DHBAP decreased by 26.3%, 21.3%, 37.0% and 60.9% when compared with neat EP, respectively, indicating that DHBAP had good inhibition on heat and smoke releases. Eventually, the flame-retardant mechanism of DHBAP was further explored by X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The results showed that DHBAP had good flame-retardant activity in the gasous-condensed two phases.
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高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2018
·Vol. 29
·期 7
·1939-1952
·
IF 2.137
Xiang Shi,HongXin Shi,HongKe Wu,HaiMin Shen,Peng Cao
In the current study, the novel fluorinated polyurethanes (FPUs) that contained the gemini branched fluoroether side groups on the hard segments were developed. In brief, to obtain these FPUs, a new class of fluorinated gemini diol with double-branched fluoroether side groups was first synthesized and characterized by using Fourier transform infrared spectroscopy, nuclear magnetic resonance, and mass spectrometry. Subsequently, a series of FPUs were designed and prepared by using hexamethylene diisocyanate, poly (tetramethylene oxide glycol), 1,4-butanediol, and fluorinated gemini diol. Analysis of the FPUs' surface properties from contact angle analysis indicated that the water contact angle increased from 81° to more than 120° when the content of fluorinated gemini diol was increased. Differential scanning calorimetry results revealed that introduction of fluorinated gemini dio decreased the T g of FPUs, causing a better phase separation. Results from thermogravimetric analysis studies indicated the thermal stability of FPUs was improved. Scanning electron microscopy and energy dispersive X-ray spectroscopy revealed that fluoroether groups migrate to and enrich on the outmost surface of FPUs.
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高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2018
·Vol. 29
·期 7
·2002-2009
·
IF 2.137
Man Xi,Yang Jiang
A series of methoxypolyethylene glycol-terminated self-fluorescent polyurethane multi-block copolymers with excellent pH-responsivity, self-fluorescence, and biocompatibility are designed and synthesized. In our design, 1, 4-bis (hydroxyethyl) piperazine is chosen as a pH-responsive segment which can donate or accept protons in response to the change of environmental pH, and fluorescein isothiocyanate is used as a fluorescent dye conjugated into the micelles to offer self-fluorescence. The chemical structure of the polyurethane multi-block copolymers is characterized by nuclear magnetic resonance and Fourier transform infrared spectroscopy. The results of the acid-based titration, the fluorescence spectrometry, and the ultraviolet visible spectroscopy indicate that the polyurethane multi-block copolymers own an excellent pH-buffering capacity responded to the change of pH values and the favorable self-fluorescence property in an aqueous solution. And the ultraviolet absorption peaks of samples are strengthened with increasing of pH values, indicating that methoxypolyethylene glycol-terminated self-fluorescent polyurethane multi-block copolymer can be a pH-dependent fluorescent probe in a broad pH range. In addition, the in vitro cytotoxicity test showed that the polyurethane multi-block copolymer has low cytotoxicity and good biocompatibility, which make it a promising nanoplatform for molecular imaging, diagnosis, and treatment of disease.
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高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2018
·Vol. 30
·期 4
·923-931
·
IF 2.137
Shengqiang Nie,Jiazhou Zeng,Hui Qin,Xiaolu Xu,Jia Zeng,Chunlin Yang,Jun Luo
In this study, we have provided a highly efficient, convenient, and universal protocol for preparing polyvinylidene fluoride (PVDF) membranes with low blood contact activation via in situ cross-linking copolymerization of 2-hydroxyethl methacrylate (HEMA) and acrylic acid (AA) in a solution of PVDF. The modified membranes were prepared from PVDF solution by phase inversion technology. The composition and morphology of the modified membranes were confirmed by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, thermogravimetric (TG) analysis, and scanning electron microscopy (SEM). Protein adsorption, clotting time, and contact activation on the modified PVDF membranes were systematically studied, the results indicating that after the incorporation of AA and HEMA, the modified PVDF membranes possessed anticoagulant properties in addition to low contact activation of blood components when in contact with blood. Therefore, fluorinated PVDF membranes with surfaces enriched with carboxyl and hydroxyl groups possessed the potential for use in long-term blood-contacting devices.
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高影响因子
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