JOURNAL OF APPLIED POLYMER SCIENCE
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2013
·Vol. 131
·期 10
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IF 1.395
Hongtao Liu,Jiangang Zhou,Danying Zuo,Xiuying Liu,Shaojin Gu,Weilin Xu
Morphological, thermal, and mechanical features of electrosprayed and electrospun deposition of the silk-inspired polyurethane (PU) containing GlycineAlanineGlycineAlanine (GlyAlaGlyAla, the featured peptide sequence of silkworm silk fibroin) tetrapeptide, which was synthesized by the traditional liquid-phase peptide synthesis method and the classical two-step polymerization method using Boc-protected amino acids and diisocyanates as starting materials, were characterized. The results show that the synthesized silk-inspired PU dissolved in tetrahydrofuran (THF) can be easily electrosprayed or electrospun into the film form, although its molecular weight ranging from 13,000 to 15,000 is quite low. Elastomeric fibrous membranes with surface morphologies of “droplets,” “bead-on-string,” and “nonwoven fibers” have been obtained by electrospraying and electrospinning the silk-inspired PU/THF solution of varying concentrations. The thermograms confirm high thermostability of the silk-inspired PU between 350 and 400°C due to the polar peptide linkages. The tanδ peak of dynamic mechanical analysis curve corresponding to its glass transition temperatures is detected at −34.3°C. Its elongation at break is about 140–150%, and the breaking tensile strength ranges from 22 to 27 MPa, which is consistent with the data of other PUs containing l -alanine residue. Information provided by this study can be used to better understand the correlation between the natural and man-made silk polymers. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 40245.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2013
·Vol. 131
·期 8
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IF 1.395
Yanming Hu,Chunqing Zhang,Xianguang Liu,Keke Gao,Yuming Cao,Chunyu Zhang,Xuequan Zhang
The polymerization of isoprene was examined by using a novel binary catalyst system composed of neodymium chloride tributylphosphate (NdCl 3 ·3TBP) and methylaluminoxane (MAO). The NdCl 3 ·3TBP/MAO catalyst worked effectively in a low MAO level ([Al]/[Nd] = 50) to afford polymers with high molecular weight ( M n ∼10 5 ), narrow molecular weight distribution ( M w / M n = 1.4–1.6), and high cis -1,4 stereoregularity (> 96%). The catalytic activity increased with an increasing [Al]/[Nd] ratio from 30 to 100 and polymerization temperature from 0 to 50°C, while the M n of polymer decreased. The presence of free TBP resulted in low polymer yield. Polymerization solvent remarkably affected the polymerization behaviors; the polymerizations in aliphatic solvents (cyclohexane and hexane) gave polymer in higher yield than that in toluene. The M w / M n ratio of the producing polymer remained around 1.5 and the gel permeation chromatographic curve was always unimodal, indicating the presence of a single active site in the polymerization system. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 40153.
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JOURNAL OF APPLIED POLYMER SCIENCE
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2013
·Vol. 131
·期 8
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IF 1.395
Songfang Zhao,Guoping Zhang,Rong Sun,Chingping Wong
In this article, novolac epoxy was functionalized using p -hydroxybenzoic acid as pendent groups, which offered weak acidic environment and were cured with methyl etherified amino resin (HMMM). Its chemical structure was characterized by Fourier transform infrared (FT-IR), 1 H nuclear magnetic resonance ( 1 H NMR) and differential scanning calorimeter (DSC). To comprehensively investigate its performance, HMMM was used as a curing agent. The modified epoxy exhibited higher storage modulus, lower thermal expansion coefficient, better moisture resistance, better resistance to degradation and lower dielectric constant. Furthermore, the aging behavior was investigated using dynamic mechanical analysis and scanning electron microscopy, which showed that the activation energy of glass transition increased after aging and cured MDEN was more difficult to age. Moreover, the relation between storage modulus and curing rate was established; the low curing rate of MDEN decreased the growth rate of storage modulus and reduced the internal stress, which was beneficial for processing. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 40157.
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JOURNAL OF APPLIED POLYMER SCIENCE
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2015
·Vol. 133
·期 9
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IF 1.768
Xiangxiang Du,Guohua Jiang,Lei Li,Wentong Yang,Hua Chen,Yongkun Liu,Qin Huang
Glucose-sensitive and fluorescence copolymer micelles were designed and prepared via a combination of photoinitiated polymerization and enzymatic transesterification. The water-soluble photoinitiator and emulsifier 2-oxooctanoic acid self-polymerized dimer molecules under UV irradiation were characterized by mass spectrometry. The fluorescence dye (9-anthracene alcohol) and biocompatible hydrophilic chains [poly(ethylene glycol)] were introduced to the polymer chains during the photopolymerization and enzymatic transesterification processes. The as-prepared copolymers were confirmed by 1 H-NMR spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, and dynamic light scattering. The resulting copolymers exhibited excellent glucose sensitivity and stability against protein. The optical fluorescence properties of the copolymer micelles were investigated with fluorescence spectrophotometry, fluorescence microscopy, and confocal laser scanning microscopy. Because of the amphiphilic feature, the micelles could be self-assembled and used to load insulin. The controlled release of insulin was evaluated and was triggered by glucose in vitro . This study provided a new strategy for fabricating functional carriers as self-regulated insulin-release systems. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133 , 43026.
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JOURNAL OF APPLIED POLYMER SCIENCE
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2015
·Vol. 133
·期 5
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IF 1.768
Hao Ying,Guijin He,Lifeng Zhang,Qunfang Lei,Yongsheng Guo,Wenjun Fang
Hydrogels were synthesized from hyperbranched polyglycerol (HPG) and acrylic acid through free-radical polymerization with HPG as the crosslinker. The HPG/poly(acrylic acid) (PAA) hydrogel could absorb cationic dyes in aqueous solutions because of the existence of a porous structure and the large numbers of hydroxyl and carboxylic groups. With methyl violet chosen as a model compound, the HPG/PAA hydrogel reached a maximum adsorption of 394.12 mg/g at a feed concentration of 1 g/L. The highest removal ratio of 98.33% was observed at a feed concentration of 50 mg/L. The effects of the pH, contact time, and feed concentration on the dye adsorption were investigated. The dye adsorption data fit well with the pseudo-second-order and Langmuir models. We believe that the HPG/PAA hydrogels could perform well in appropriate applications in the removal of cationic dyes from aqueous solutions because of their high adsorption capacity and environmental friendliness. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133 , 42951.
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JOURNAL OF APPLIED POLYMER SCIENCE
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2015
·Vol. 132
·期 46
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IF 1.768
Yonggang Guo,Zhongying Wang,Haihong Wu,Xia Zhang
A facile casting method was used to fabricate superhydrophobic polyimide/polytetrafluoroethylene composite coatings with high water adhesion. The water contact angles of the composite coatings were larger than 150 °, expressing superhydrophobic property. But water droplets pinned tightly on the composite coating, even if it was upside down. The X-ray photoelectron spectrum analysis indicated that polyimide and polytetrafluoroethylene coexisted in the resulting coating. The observation with scanning electron microscopy showed that the composite coating formed lotus-like structure with many spherical polyimide papillae randomly bonding on the surface. But the tops of the polyimide papillae were not covered by lance-shaped Teflon fibres, forming an inhomogenous and discontinuous surface structure. This special surface chemical distribution and lotus-like structure combined to contribute to the high adhesive superhydrophobicity. This simple method may greatly extend the application range of high adhesive superhydrophobic surfaces in microcontrollable and microfluidic application. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 42810.
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JOURNAL OF APPLIED POLYMER SCIENCE
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2015
·Vol. 132
·期 34
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IF 1.768
Xiangyan Liu,Deng Hu,Meng Li,Jianming Zhang,Zhigao Zhu,Gaofeng Zeng,Yanfeng Zhang,Yuhan Sun
To improve the pervaporation performance of Silicalite-1/PDMS composite membrane by adding a small amount of Silicalite-1 zeolite, novel Silicalite-1/PDMS surface sieving membranes (SSMs) were prepared by attaching Silicalite-1 particles on the PDMS membrane surface. The obtained membranes and traditional mixed-matrix membranes (MMMs) were characterized by SEM, XRD, TGA, FT-IR, and pervaporation separation of ethanol–water mixture. Effects of Silicalite-1 particles content, feed temperatures, and feed compositions on the separation performance were discussed. From the cross-section view SEM images of SSMs, a two-layer structure was observed. The thickness of the Silicalite-1 layer was about 300 nm to 2 μm. The TGA analysis indicates that the zeolite concentration in 3 wt % SSM is lower than 10 wt % MMMs. In the ethanol/water pervaporation experiment, the separation factor of Silicalite-1/PDMS SSMs increased considerably compared with pure PDMS membrane. When the suspensions concentrations of Silicalite-1 particles reached 3 wt %, the separation factor was about 217% increase over pure PDMS membrane and 52.9% increase over 10 wt % Silicalite-1/PDMS MMMs. As the ethanol concentration in the feed increases, the separation factor of SSMs increases, whereas permeation flux decreases. At the same time, with increasing operating temperature, the permeation flux of SSMs increased. The stability of SSMs at high temperature is better than the traditional MMMs. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 42460.
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JOURNAL OF APPLIED POLYMER SCIENCE
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2015
·Vol. 132
·期 32
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IF 1.768
Zhengyan Tan,Hong Peng,Hongfang Liu,Linling Wang,Jing Chen,Xiaohua Lu
A novel magnetic adsorbent (EDTA /chitosan/ PMMS) was facilely prepared by reacting chitosan with EDTA anhydride in presence of PEI - coated magnetic microspheres. The as-synthesized EDTA/ chitosan /PMMS was characterized by XRD, SEM, TGA, FT-IR , and VSM, and then employed in removal of heavy metals of Pb(II) from aqueous solution. The results of the batch adsorption experiments revealed that the adsorbents had extremely high uptake capacities for Pb(II) in the pH range of 2 to 5.5, and the adsorption kinetics for EDTA/ chitosan /PMMS was consistent with the pseudo – second - order kinetic model. Moreover, its equilibrium data were fitted with the Langmuir isothermal model well, which indicated that the adsorption mechanism was a homogeneous monolayer chemisorptions process. The maximum adsorption capacity of EDTA/ chitosan /PMMS for Pb(II) was found to be 210 mg g − 1 at pH 4 (30 ° C), and further reuse experiments results suggested that EDTA /chitosan/ PMMS could be a potential recyclable magnetic adsorbent in the practical wastewater treatment. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 42384.
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JOURNAL OF APPLIED POLYMER SCIENCE
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2014
·Vol. 132
·期 8
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IF 1.64
Huining Deng,Zixia Wang,Wei Zhang,Baisong Hu,Shaofeng Zhang
This study reports the modification of commercial cation-exchange membrane by layer-by-layer adsorption of polyethyleneimine and poly(acrylic acid) (PAA) to endow them with monovalent ion selectivity. The chemical and morphological changes of the modified membrane surface were examined by ATR-FTIR and SEM, respectively. The permselectivity for monovalent cations of the membranes was investigated by electrodialysis experiments. The effects of deposited bilayer number, the salt concentration, and pH of the dipping polyelectrolyte solutions on selectivity were investigated. Meanwhile, the resistance of membranes was measured taking energy consumption into consideration. The polyelectrolyte multilayer was crosslinked using epichlorohydrin to improve stability, and the durability of the composite membrane was studied. Separation mechanism of the composite membrane was also investigated. It is demonstrated that the bivalent cations are mainly rejected by electrostatic repulsion from the positive charge on the surface of the composite membranes. The sieving effect of the dense structure of skin layer becomes more pronounced with the number of deposited layers increased. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 41488.
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JOURNAL OF APPLIED POLYMER SCIENCE
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2014
·Vol. 132
·期 6
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IF 1.64
Ziqing Cai,Xiaoyu Meng,Xiaocan Zhang,Lishan Cui,Qiong Zhou
In this study, the effects of carbon nanofiber (CNF) surface modification on mechanical properties of polyamide 1212 (PA1212)/CNFs composites were investigated. CNFs grafted with ethylenediamine (CNF- g -EDA), and CNFs grafted with polyethyleneimine (CNF- g -PEI) were prepared and characterized. The mechanical properties of the PA1212/CNFs composites were reinforced efficiently with addition of 0.3 wt % modified CNFs after drawing. The reinforcing effect of the drawn composites was investigated in terms of interfacial interaction, crystal orientation, crystallization properties and so on. After the surface modification of CNFs, the interfacial adhesion and dispersion of CNFs in PA1212 matrix were improved, especially for CNF- g -PEI. The improved interfacial adhesion and dispersion of CNFs in PA1212 matrix was beneficial to reinforcement of the composites. Compared with pure PA1212, improved degree of crystal orientation in the PA1212/CNF- g -PEI (CNF- g -EDA) composites was responsible for reinforcement of mechanical properties after drawing. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 41424.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2014
·Vol. 132
·期 5
·
IF 1.64
He Xiao,Beihai He,Liying Qian,Junrong Li
In a paper mill's water circuit, normal runnability of the paper machine is often disturbed due to the buildup of dissolved and colloidal substances (DCS). Contaminant adsorption on a solid adsorbent in a fluidized bed reactor has been applied for white water treatment. In the present study, polystyrene (PS) spheres were firstly acylated by acryloyl chloride, then poly(methacryloxyethyltrimethyl ammonium chloride) (PMAC) was grafted onto the acylated PS spheres, induced by surface-initiated free-radical polymerization. Fourier transform infrared spectroscopy, thermal gravimetric analysis, and scanning electron microscopy were used to characterize the changes of PS spheres in chemical structures and surface morphology. The results showed that acylated PS spheres could be easily grafted with PMAC in 53.83% weight increase. Polyelectrolyte loading of PS spheres reached up to 1.72 mmol/g. The resulted cationic modified PS spheres could effectively decrease the cationic demand in white water and it still maintained high performance after operating repeatedly for 10 batches. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 10.1002/app.41379.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2014
·Vol. 132
·期 5
·
IF 1.64
Meng Su,Jianqiang Chen,Zhenhong Pan,Xiaobao Li,Anqi Xu,Jianguo Hong
The objectives of this study were to prepare injection-moulded wood-based plastics and to characterize their mechanical properties. Injection-moulded wood-based plastics with satisfactory flexural (65.7 MPa) and tensile strengths (30.1 MPa) were successfully obtained through a simple reaction of mulberry branch meal with phthalic anhydride (PA) in 1-methylimidazole under mild condition. The X- ray diffraction results indicated complete disruption of the crystallinity of cellulose because the pattern obtained for esterified fiber was almost a straight line without any peaks. The peaks in the Fourier transform infrared spectroscopy spectra (1738 and 748 cm −1 ) and NMR spectra (173.3 and 133.5 ppm) indicated the attachment of 0-carboxybenzoyl groups onto the wood fibers via ester bonds. The differential scanning calorimetry curves showed that the glass transition temperature decreased with increasing weight percentage gain (WPG). The derivative thermogravimetric analysis curves indicated that esterified wood fiber was less thermally stable than the untreated fiber and that the component tends to be homogeneous with increasing WPG. Scanning electron microscope revealed that the fractured surfaces of most samples were smooth and uniform but that high temperature and less PA dosage could lead to the appearance of holes and cracks. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 41376.
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