魏士明, 俞紀(jì)賢, 陳 麗, 胡真虎, 楊 文, 郝文濤

(1.合肥工業(yè)大學(xué) 化學(xué)工程學(xué)院,安徽 合肥 230009; 2.合肥工業(yè)大學(xué) 土木與水利工程學(xué)院,安徽 合肥 230009)

雙噴頭靜電紡絲法制備PU增強(qiáng)增韌PVA復(fù)合膜

魏士明1, 俞紀(jì)賢1, 陳 麗1, 胡真虎2, 楊 文1, 郝文濤1

(1.合肥工業(yè)大學(xué) 化學(xué)工程學(xué)院,安徽 合肥 230009; 2.合肥工業(yè)大學(xué) 土木與水利工程學(xué)院,安徽 合肥 230009)

文章采用雙噴頭靜電紡絲法制備了聚乙烯酸/聚氨酯(PVA/PU)復(fù)合膜。掃描電子顯微鏡(scanning electron microscope,SEM)表征結(jié)果表明PVA/PU復(fù)合膜中PU電紡膜與PVA電紡膜在交叉點上有明顯的粘連。差示掃描量熱儀(differential scanning calorimeter,DSC)分析結(jié)果顯示復(fù)合膜中PVA的玻璃化轉(zhuǎn)變溫度降低,間接地反映出PVA電紡膜與PU電紡膜有較強(qiáng)的聯(lián)系和相互作用。因此,PVA/PU復(fù)合膜在受力形變過程中,應(yīng)力能夠有效地在PVA間傳遞,從而提高了復(fù)合膜的拉伸強(qiáng)度;由于PU電紡膜具有很高的柔性,復(fù)合膜的斷裂伸長率也得以大幅提升。該實驗所制備的PVA/PU復(fù)合膜具有較強(qiáng)的力學(xué)性能和良好的生物相容性等特點,使得該復(fù)合膜在生物醫(yī)學(xué)研究(組織工程、傷口敷料、藥物釋放等)領(lǐng)域具有良好的潛在應(yīng)用價值。

聚乙烯醇;聚氨酯;雙噴頭;靜電紡絲;力學(xué)性能

聚乙烯醇(PVA)具有良好的水溶性、生物相容性及生物可降解性等特點,是一種具有良好可紡性的聚合物。PVA的靜電紡絲膜可被用于組織工程[1-3]、人造皮膚[4-6]和藥物釋放[7]等研究領(lǐng)域。同時在抗菌[8-9]、反光材料[10]、發(fā)光材料[11]和水處理[12-14]等其他領(lǐng)域也有著良好的應(yīng)用前景。但是PVA靜電紡絲纖維膜的力學(xué)性能不佳[15],通常都低于10 MPa。

當(dāng)前,研究者們從微觀角度出發(fā)提出很多方案來提升PVA電紡纖維的強(qiáng)度,從而在宏觀上增強(qiáng)PVA靜電紡絲膜的力學(xué)性能。常見的方法是將碳納米管[16-18]、微晶纖維素[19-20]、無機(jī)納米粒子[21-24]與聚合物溶液共混后紡絲得到力學(xué)性能增強(qiáng)的電紡膜。但是PVA電紡膜自身的強(qiáng)度[25-26]實際上為62～80 MPa?？梢酝茰y,PVA電紡膜強(qiáng)度不高是因為纖維間無緊密的聯(lián)系,從而在受力形變過程中無法協(xié)同抵抗外力作用。此外,無機(jī)納米粒子的混入會阻礙PVA分子運動,導(dǎo)致PVA電紡膜的斷裂伸長率比原始PVA電紡膜低。因此,采用增強(qiáng)PVA單絲的方法來提高電紡膜整體的力學(xué)性能并不是理想的選擇。最近,有報道提出利用化學(xué)交聯(lián)方法來增強(qiáng)PVA纖維膜[27-29],但是,在交聯(lián)后,PVA電紡膜的形變能力會受到很大限制,電紡膜的斷裂伸長率也會降低。當(dāng)采用溶劑處理,產(chǎn)生表面融合的方法來物理交聯(lián)電紡纖維膜時[30-32],電紡纖維會發(fā)生溶脹、松弛,堵塞纖維膜內(nèi)的空隙。

多噴頭靜電紡絲法是最近研究比較多的一種新型紡絲技術(shù)。通過多噴頭靜電紡絲,可以將不同種類和不同物性的聚合物共紡絲在同一接收器上,從而得到具有多樣化性能和功能的復(fù)合電紡膜[33-36]。例如,通過將磺化的聚醚酮和非磺化的聚醚酮共紡絲形成復(fù)合纖維膜,可以構(gòu)建具有分相結(jié)構(gòu)的質(zhì)子交換膜,在一定程度上模擬了Nafion膜的多相結(jié)構(gòu)[37];在瓊脂糖/聚丙烯酸/聚丙烯腈復(fù)合電紡膜中,瓊脂糖/聚丙烯酸纖維提供了良好的離子螯合能力,而聚丙烯腈纖維則為復(fù)合膜提供了良好的力學(xué)強(qiáng)度[38]。受上述研究啟發(fā),本文將一種具有柔性和粘接性能的聚合物與PVA進(jìn)行雙噴頭共紡絲,PVA電紡纖維間將會被柔性連接起來,增強(qiáng)纖維間的相互聯(lián)系與相互作用,從而能夠在提高PVA纖維協(xié)同抵抗外力作用的同時,提高電紡膜的延展性。

本文利用雙噴頭靜電紡絲法制備了PVA與聚氨酯(PU)的復(fù)合膜，這種復(fù)合膜與原始PVA電紡膜相比,不僅強(qiáng)度提高,而且斷裂伸長率也有大幅提升。因為PVA和PU均具有良好的生物相容性[39-40],所以PVA/PU復(fù)合膜在組織工程、傷口敷料、藥物釋放等領(lǐng)域都有巨大的潛在應(yīng)用價值。

1 實驗部分

1.1 實驗原料

聚乙烯醇(PVA-1788),安徽皖維高新材料股份有限公司;聚氨酯(35% DMF溶液),室溫下黏度為5×104mPa·s,安徽安利合成革股份有限公司;N,N-二甲基甲酰胺(DMF),國藥集團(tuán)化學(xué)試劑有限公司。

1.2 實驗儀器

自制靜電紡絲儀器如圖1所示。主要設(shè)備為2臺DW-P403-1ACDF型高壓直流電源,東文高壓電源(天津)有限公司。復(fù)合膜的力學(xué)性能采用CMT5000型電子萬能試驗機(jī)測試,深圳市新三思材料檢測有限公司;拉伸試樣的尺寸均為50 mm×20 mm,試樣厚度為(0.10± 0.02) mm,拉伸測試速率為10 mm/min;復(fù)合膜的表面形貌采用JSM-6700F型場發(fā)射掃描電子顯微鏡(scanning electron microscope,SEM)觀察,日本JEOL公司;其他實驗儀器有:DSC-822e型差示掃描量熱儀(differential scanning calorimeter,DSC),瑞士梅特勒-托利多公司,N2氣氛,測試溫度范圍為室溫至200 ℃,升溫速率10 ℃/min;Nicolet iS10型傅里葉轉(zhuǎn)換紅外光譜分析儀(Fourier transform infared spectroscopy,FTIR),美國賽默飛公司。

圖1 雙噴頭靜電紡絲設(shè)備示意圖

1.3 實驗步驟

取10 g的PVA分散于90 g的去離子水中,90 °C攪拌12 h,得到透明均勻的質(zhì)量分?jǐn)?shù)為10% PVA水溶液。將一定量的PU原液稀釋為15%的PU/DMF溶液。PVA、PU溶液的紡絲電壓分別為12、15 kV。針頭到接收器的距離設(shè)定為15 cm,接收器轉(zhuǎn)速為200 r/min。一般經(jīng)過5 h紡絲后,可以得到厚度為(0.10 ± 0.02) mm的復(fù)合膜。電紡過程中,PVA流量控制為0.1 mL/h,并通過調(diào)節(jié)PU溶液的流量來得到不同PU質(zhì)量分?jǐn)?shù)的復(fù)合膜。最后,通過熱水溶解、烘干后稱重的方式確定復(fù)合電紡膜中PU的實際質(zhì)量分?jǐn)?shù),并按照PVA和PU相對比例命名所得樣品。例如,含有約20 %的PU電紡纖維的復(fù)合膜被命名為PVA/PU 80/20。

2 結(jié)果討論

2.1 PVA膜和PVA/PU復(fù)合膜的光學(xué)照片

PVA電紡膜和PVA/PU復(fù)合膜的光學(xué)照片如圖2所示。

從圖2a可以看出,PVA電紡膜表面光滑平整,然而在拉伸斷裂后,出現(xiàn)明顯的分層現(xiàn)象。由于電紡膜內(nèi)PVA纖維間可能并無強(qiáng)的聯(lián)系與相互作用,在受力拉伸時,PVA纖維不能協(xié)同抵抗外力作用。部分與外力方向平行的纖維會被首先拉斷,從而產(chǎn)生連續(xù)破壞,最終導(dǎo)致明顯的分層現(xiàn)象。從圖2c和圖2d可以看出,PU的引入抑制了PVA電紡膜的斷裂分層現(xiàn)象；當(dāng)PU質(zhì)量分?jǐn)?shù)為20%時,復(fù)合膜受力斷裂后的分層程度減弱。當(dāng)PU質(zhì)量分?jǐn)?shù)為30%時,復(fù)合膜斷裂時完全沒有分層。這應(yīng)歸于PVA纖維能夠通過PU纖維的粘接有效地將應(yīng)力分散到同一層和不同層的其他PVA纖維上。

圖2 PVA電紡膜和PVA/PU復(fù)合膜的光學(xué)照片

2.2 PVA/PU復(fù)合膜的形態(tài)

在對靜電紡絲膜的研究過程中,SEM是一種非常有力的表征手段。本文通過觀察SEM照片能發(fā)現(xiàn)PU電紡膜與PVA電紡膜間存在相互作用的證據(jù)。

純PVA電紡膜、純PU電紡膜以及PVA/PU復(fù)合膜的形態(tài)如圖3所示。從圖3a可以看出，PVA纖維彼此孤立,交叉點上并無粘連，但PU纖維之間存在明顯的相互綁定,粘連比較嚴(yán)重。這可能是由于PU電紡時所用的溶劑為DMF,具有很高的沸點(～153 °C)。DMF在電紡過程中不易完全揮發(fā),因而在PU纖維中可能會有少量殘留。此時,PU仍具有很好的粘接性能,PU電紡絲之間就發(fā)生了相互粘連。從圖3c可以看出,在PVA/PU復(fù)合膜內(nèi),較粗的PU纖維與較細(xì)的PVA纖維交錯分布、相互交織，在PVA纖維與PU纖維的交叉點上,發(fā)生了粘連。由于PVA纖維與PU纖維同時沉積在接收器上,形成交錯的織態(tài)結(jié)構(gòu),復(fù)合膜內(nèi)的PVA電紡纖維就緊緊地被PU纖維綁定在一起。

圖3 純PVA電紡膜、純PU電紡膜和PVA/PU復(fù)合膜的SEM照片

2.3 DSC和FTIR分析

當(dāng)PVA纖維與PU纖維間存在相互作用時,PVA纖維內(nèi)的分子運動能力可能會發(fā)生變化。DSC是分析聚合物材料的分子運動,特別是玻璃化轉(zhuǎn)變現(xiàn)象的一種非常有效的手段。本文采用DSC分析了PVA以及PVA/PU復(fù)合膜的玻璃化轉(zhuǎn)變溫度(Tg),結(jié)果見表1所列。由表1可看出,隨著PU質(zhì)量分?jǐn)?shù)的增加,PVA/PU復(fù)合膜的Tg逐漸降低。從高分子物理基本原理可知,當(dāng)共混體系中2種聚合物之間存在一定相容性的條件下,聚合物間會存在相互牽制,導(dǎo)致具有高Tg值的聚合物的Tg會向低溫方向移動。在PVA/PU復(fù)合膜中,2種聚合物雖然不相容,但是2種聚合物的電紡纖維間卻應(yīng)存在較強(qiáng)的相互作用,從而使PVA的Tg降低。

表1 不同PU質(zhì)量分?jǐn)?shù)下復(fù)合膜轉(zhuǎn)變溫度

PVA電紡膜和PVA/PU復(fù)合膜的FTIR光譜圖如圖4所示。

圖4 不同PU質(zhì)量分?jǐn)?shù)下復(fù)合膜的FTIR譜

從圖4可看出，PVA的特征振動峰[41-43]有3 320 cm-1(-OH)、1 091 cm-1(C-O)和842 cm-1(C-C)；PU的特征振動峰有1 732 cm-1(C=O)[44-45]、1 532 cm-1(N-H)[46-47]和1 313 cm-1(O-CO)[48]。隨著復(fù)合膜內(nèi)PU質(zhì)量分?jǐn)?shù)的增多,PVA的特征振動峰的相對強(qiáng)度在減弱;相反,PU特征峰的相對強(qiáng)度在變強(qiáng)。但是,譜圖中并沒有發(fā)現(xiàn)有新的振動峰形成,表明PVA電紡膜和PU電紡膜之間的相互作用為物理作用。PVA與PU通過表面黏性緊密地聯(lián)系在一起。同時由于PU分子鏈上帶有大量的氨基、羰基等基團(tuán),可以與PVA的羥基間形成氫鍵作用。PVA纖維通過與PU纖維的接觸點可以連接為一個網(wǎng)絡(luò),共同承受外力作用。

2.4 PVA、PU電紡膜和復(fù)合膜力學(xué)性能

典型的PVA/PU復(fù)合膜和純PVA電紡膜的應(yīng)力-應(yīng)變曲線如圖5所示。從圖5可以看出,PVA/PU復(fù)合膜的模量稍低于PVA電紡膜,遠(yuǎn)高于純PU電紡膜;但是,復(fù)合膜的強(qiáng)度和延展性都優(yōu)于PVA電紡膜。這一結(jié)果與文獻(xiàn)[49]研究結(jié)論有較大不同。

圖5 不同PU質(zhì)量分?jǐn)?shù)下復(fù)合膜應(yīng)力-應(yīng)變曲線

PVA/PU復(fù)合膜的拉伸強(qiáng)度和斷裂伸長率如圖6所示。

圖6 不同PU質(zhì)量分?jǐn)?shù)下復(fù)合膜的力學(xué)性能

從圖6可以看出,所有復(fù)合膜的拉伸強(qiáng)度均高于PVA電紡膜，當(dāng)PU質(zhì)量分?jǐn)?shù)增加到30%時,復(fù)合膜的拉伸強(qiáng)度達(dá)到了18.86 MPa,約為純PVA電紡膜的1.8倍。隨著PU質(zhì)量分?jǐn)?shù)的增多,復(fù)合膜的斷裂伸長率持續(xù)增大,最大值可以達(dá)到248.0%,約為純PVA電紡膜的2倍。顯然,在本文所得到的PVA/PU復(fù)合膜,PVA與PU間產(chǎn)生了協(xié)同增強(qiáng)力學(xué)性能的效果。

PU是一種低模量、高柔性的樹脂，如果是簡單共混,PU電紡纖維與PVA電紡纖維交織在一起得到的PVA/PU復(fù)合膜的強(qiáng)度和模量應(yīng)介于PU與PVA電紡膜之間。但是,從圖5和圖6中均發(fā)現(xiàn)兩者之間產(chǎn)生了協(xié)同作用。這一結(jié)果可理解為PU電紡纖維通過接觸點上的粘接將PVA電紡纖維綁定在一起,提高了PVA電紡纖維的協(xié)同抵抗外力作用的能力,從而抑制了電紡膜的過早破壞,最終導(dǎo)致PVA/PU復(fù)合膜的強(qiáng)度和延展性都得以提升。在文獻(xiàn)[49]的研究中,由于采用了單電源、雙噴頭模式,難于對PVA和PU電紡過程分別調(diào)節(jié),因而研究結(jié)果有局限性。本文采用雙電源、雙噴頭的電紡模式,不僅得到了強(qiáng)度提升的復(fù)合膜,而且制得力學(xué)性能可調(diào)的聚合物復(fù)合膜。

在圖6b中,PVA/PU復(fù)合膜的斷裂伸長率雖然隨PU質(zhì)量分?jǐn)?shù)的提高而提高,但是相對于PU電紡膜來說要小很多,而且增長幅度有限。這可能由于PVA電紡膜與PU電紡膜間存在著較強(qiáng)的粘接,柔性的PU電紡膜的形變受到了相對剛性的PVA電紡膜的限制。此外,由于在復(fù)合膜中,隨PU質(zhì)量分?jǐn)?shù)的提高,PVA的質(zhì)量分?jǐn)?shù)相對下降,也會降低復(fù)合膜抵抗形變的能力。

3 結(jié) 論

本文通過雙噴頭靜電紡絲法制備了一系列不同配比的PVA/PU復(fù)合膜,發(fā)現(xiàn)PU與PVA具有協(xié)同增強(qiáng)作用。PU的加入不僅有效地提高了PVA電紡膜的拉伸強(qiáng)度,而且也提高了其斷裂伸長率。SEM和DSC測試表明PU有效地將PVA纖維結(jié)合在一起,提高了應(yīng)力在PVA纖維間的傳遞效果,并抑制了PVA纖維的過早分層與斷裂。PU是一種力學(xué)性能相對較弱的聚合物材料，以弱的材料來實現(xiàn)對復(fù)合膜的增強(qiáng)增韌是一種新的思路。本文所制備的復(fù)合膜所有組分(PVA和PU)都具有很好的生物相容性,這使得該復(fù)合膜在生物醫(yī)學(xué)研究(如組織工程、傷口輔料、藥物釋放等)領(lǐng)域具有良好的潛在利用價值。

[1] GAO Chunxia,GAO Qiang,LI Yadong,et al.Preparation and in vitro characterization of electrospun PVA scaffolds coated with bioactive glass for bone regeneration[J].Journal of Biomedical Materials Research Part A,2012,100A (5):1324-1334.

[2] LINH N T B,LEE K H,LEE B T,et al.Functional nanofiber mat of polyvinyl alcohol/gelatin containing nanoparticles of biphasic calcium phosphate for bone regeneration in rat calvaria defects[J].Journal of Biomedical Materials Research Part A,2013,101A (8):2412-2423.

[3] CHANG Wenkai,MU Xueyan,ZHU Xiaoqun,et al.Biomimetic composite scaffolds based mineralization of hydroxyapatite on electrospun calcium-containing poly (vinyl alcohol) nanofibers[J].Materials Science and Engineering:C,2013,33 (7):4369-4376.

[4] SUNDARAMURTHI D,VASANTHAN K S,KUPPAN P,et al.Electrospun nanostructured chitosan-poly (vinyl alcohol) scaffolds:a biomimetic extracellular matrix as dermal substitute[J].Biomedical Materials,2012,7(4):045005-045016.

[5] LIN H Y,KUO Y J,CHANG S H,et al.Characterization of electrospun nanofiber matrices made of collagen blends as potential skin substitutes[J].Biomedical Materials,2013,8(2):025009-025017.

[6] KRISHNAN R,RAJESWARI R,VENUGOPAL J,et al.Polysaccharide nanofibrous scaffolds as a model for in vitro skin tissue regeneration[J].Journal of Materials Science:Materials in Medicine,2012,23 (6):1511-1519.

[7] KATARIA K,GUPTA A,RATH G,et al.In vivo wound healing performance of drug loaded electrospun composite nanofibers transdermal patch[J].International Journal of Pharmaceutics,2014,469(1):102-110.

[8] NGUYEN T H,KIM Y H,SONG H Y,et al.Nano Ag loaded PVA nano-fibrous mats for skin applications[J].Journal of Biomedical Materials Research,Part B:Applied Biomaterials,2011,96B (2):225-233.

[9] RANJBAR-MOHAMMADI M,BAHRAMI S H,JOGHATAEI M T.Fabrication of novel nanofiber scaffolds from gum tragacanth/poly (vinyl alcohol) for wound dressing application:In vitro evaluation and antibacterial properties[J].Materials Science and Engineering:C,2013,33 (8):4935-4943.

[10] AHMADPOOR P,NATERI A S,MOTAGHITALAB V.The optical properties of PVA/TiO2composite nanofibers[J].Journal of Applied Polymer Science,2013,130(1):78-85.

[11] ORTAC B,KAYACI F,VURAL H A,et al.Photoluminescent electrospun polymeric nanofibers incorporating germanium nanocrystals[J].Reactive and Functional Polymers,2013,73(9):1262-1267.

[12] DHANDAYUTHAPANI B,MALLAMPATI R,SRIRAMULU D,et al.PVA/gluten hybrid nanofibers for removal of nanoparticles from water[J].ACS Sustainable Chemistry & Engineering,2014,2(4):1014-1021.

[14] HUANG Yunpeng,HU Dengmei,WEN Shihui,et al.Selective removal of mercury ions using thymine-grafted electrospun polymer nanofibers[J].New Journal of Chemistry,2014,38:1533-1539.

[15] 張春雪,袁曉燕,鄔麗麗,等.電紡聚乙烯醇超細(xì)纖維膜的性能研究[J].高分子學(xué)報,2006(2):294-297.

[16] WANG W,CISELLI P,KUZNETSOV E,et al.Effective reinforcement in carbon nanotube-polymer composites[J].Philosophical Transactions of the Royal Society of London A:Mathematical,Physical,and Engineering Sciences,2008,366 (1870):1613-1626.

[17] JEONG J S,MOON J S,JEON S Y,et al.Mechanical properties of electrospun PVA/MWNTs composite nanofibers[J].Thin Solid Films,2007,515(12):5136-5141.

[18] DING Zhaoqiang,ZHU Yanping,BRANFORD-WHITE C,et al.Self-assembled transparent conductive composite films of carboxylated multi-walled carbon nanotubes/poly (vinyl alcohol) electrospun nanofiber mats[J].Materials Letters,2014,128:310-313.

[19] LEE J,Deng Yulin.Increased mechanical properties of aligned and isotropic electrospun PVA nanofiber webs by cellulose nanowhisker reinforcement[J].Macromolecular Research,2012,20(1):76-83.

[20] LEE J,Deng Y L.Nanoindentation study of individual cellulose nanowhisker-reinforced PVA electrospun fiber[J].Polymer Bulletin,2013,70(4):1205-1219.

[21] LAMASTRA F R,BIANCO A,MERIGGI A,et al.Nanohybrid PVA/ZrO2and PVA/Al2O3electrospun mats[J].Chemical Engineering Journal,2008,145(1):169-175.

[22] QIN Q,LIU Y,CHEN S C,et al.Electrospinning fabrication and characterization of poly (vinyl alcohol)/layered double hydroxides composite fibers[J].Journal of Applied Polymer Science,2012,126 (5):1556-1563.

[23] WANG Chen,LI Yadong,DING Guqiao,et al.Preparation and characterization of graphene oxide/poly (vinyl alcohol) composite nanofibers via electrospinning [J].Journal of Applied Polymer Science,2013,127(4):3026-3032.

[24] WANG Zelong,CAI Ning,ZHAO Dongpeng,et al.Mechanical reinforcement of electrospun water-soluble polymer nanofibers using nanodiamonds[J].Polymer Composites,2013,34(10):1735-1744.

[25] HANG F,LU D,BAILEY R J,et al.In situ tensile testing of nanofibers by combining atomic force microscopy and scanning electron microscopy[J].Nanotechnology,2011,22(36):365708.

[26] HANG F,LU D,LI S W,et al.Stress-strain behavior of individual electrospun polymer fibers using combination AFM and SEM[C]//Mater Res Soc Symp Proc,Vol 1185. Cambridge，Eng:Cambridge University Press,2009:1185-II07-10.

[27] PERESIN M S,VESTERINEN A H,HABIBI Y,et al.Crosslinked PVA nanofibers reinforced with cellulose nanocrystals:water interactions and thermomechanical properties[J].Journal of Applied Polymer Science,2014,131(11):169-172.

[28] NAEBE M,LIN T,TIAN W,et al.Effects of MWNT nanofillers on structures and properties of PVA electrospun nanofibres[J].Nanotechnology,2007,18(22):225605-8.

[29] NAEBE M,LIN T,STAIGER M P,et al.Electrospun single-walled carbon nanotube/polyvinyl alcohol composite nanofibers:structure-property relationships[J].Nanotechnology,2008,19(30):305702-8.

[30] HUANG L W,MANICKAM S S,MCCUTCHEON J R.Increasing strength of electrospun nanofiber membranes for water filtration using solvent vapor[J].Journal of Membrane Science,2013,436:213-220.

[31] BANSAL A,SINHA A.Dehydration driven changes in the structure and mechanical behavior of electrospun poly (vinyl alcohol) nanofibers[J].Materials Science and Engineering:C,2012,32(3):587-593.

[32] DING Z Q,ZHU Y,BRANFORD-WHITE C,et al.Self-assembled transparent conductive composite films of carboxylated multi-walled carbon nanotubes/poly (vinyl alcohol) electrospun nanofiber mats[J].Materials Letters,2014,128:310-313.

[33] DUAN Bin,WU Lili,YUAN Xiaoyan,et al.Hybrid nanofibrous membranes of PLGA/chitosan fabricated via an electrospinning array[J].Journal of Biomedical Materials Research Part A,2007,83A (3):868-878.

[34] SUN Min,LI Xiaohong,DING Bin,et al.Mechanical and wettable behavior of polyacrylonitrile reinforced fibrous polystyrene mats[J].Journal of Colloid and Interface Science,2010,347 (1):147-152.

[35] ZHANG Chaoqun,LI Yapeng,WANG Wei,et al.A novel two-nozzle electrospinning process for preparing microfiber reinforced pH-sensitive nano-membrane with enhanced mechanical property[J].European Polymer Journal,2011,47 (12):2228-2233.

[36] WANG Shuai,YANG Yubo,ZHANG Yang,et al.Fabrication of large-scale superhydrophobic composite films with enhanced tensile properties by multinozzle conveyor belt electrospinning[J].Journal of Applied Polymer Science,2014,131(1):1-15.

[37] OROUJZADEH M,MEHDIPOUR-ATAEI S,ESFANDEH M.Microphase separated sepiolite-based nanocomposite blends of fully sulfonated poly (ether ketone)/non-sulfonated poly (ether sulfone) as proton exchange membranes from dual electrospun mats[J].RSC Advances,2015,5:72075-72083.

[38] KIM J M,KIM C,YOO S,et al.Agarose-biofunctionalized,dual-electrospun heteronanofiber mats:toward metal-ion chelating battery separator membranes[J].Journal of Materials Chemistry A,2015,3 (20):10687-10692.

[39] LIU Hongtao,ZHOU Jiangang,LIU Xiuying,et al.Silk-inspired polyurethane containing GlyAlaGlyAla tetrapeptide.II.Physical properties and structure[J].Journal of Applied Polymer Science,2013,130 (1):631-637.

[40] BERGMEISTER H,SCHREIBER C,GRASL C,et al.Healing characteristics of electrospun polyurethane grafts with various porosities[J].Acta Biomaterialia,2013,9(4):6032-6040.

[41] HEMALATHA K S,RUKMANI K,SURIYAMURTHY N,et al.Synthesis,characterization and optical properties of hybrid PVA-ZnO nanocomposite:a composition dependent study[J].Materials Research Bulletin,2014,51:438-446.

[43] ABDAL-HAY A,KIM C I,LIM J K.An in situ hydrothermal fabrication process of poly (vinyl alcohol)/apatite-like nanocomposites with improved thermal and mechanical properties[J].Ceramics International,2014,40(3):4995-5000.

[44] SEMSARZADEH M A,SADEGHI M,BARIKANI M.Effect of chain extender length on gas permeation properties of polyurethane membranes[J].Iranian Polymer Journal,2008,17(6):431-440.

[45] KANNAN A G,CHOUDHURY N R,DUTTA N.Fluoro-silsesquioxane-urethane hybrid for thin film applications[J].ACS Applied Materials & Interfaces,2009,1(2):336-347.

[46] OATEN M,CHOUDHURY N R.Silsesquioxane-urethane hybrid for thin film applications[J].Macromolecules,2005,38(15):6392-6401.

[47] 齊正旺,陳煒,趙長艷,等.水性形狀記憶聚氨酯的合成及性能研究[J].合肥工業(yè)大學(xué)學(xué)報(自然科學(xué)版),2009,32(8):1173-1177.

[48] DALIR H,FARAHANI R D,NHIM V,et al.Preparation of highly exfoliated polyester-clay nanocomposites:process-property correlations[J].Langmuir,2011,28(1):791-803.

[49] GU Mingbo,WANG Kaitao,LI Wenli,et al.Preparation and characterization of PVA/PU blend nanofiber mats by dual-jet electrospinning[J].Fibers and Polymers,2011,12(1):65-72.

(責(zé)任編輯 閆杏麗)

PVA composite films strengthened and toughened by PU via dual-jet electrospinning

WEI Shiming1, YU Jixian1, CHEN Li1, HU Zhenhu2, YANG Wen1, HAO Wentao1

(1.School of Chemical Engineering, Hefei University of Technology, Hefei 230009, China; 2.School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei 230009, China)

In this paper, poly(vinyl alcohol)/polyurethane(PVA/PU) composite films were fabricated via dual-jet electrospinning. The observation results of scanning electron microscope(SEM) showed that there were apparent adhesion between PVA fibers and PU fibers on the joints in the composite films. The analysis results of differential scanning calorimeter(DSC) showed that the glass transition temperature of PVA shifted to lower temperatures. It indirectly indicated that there were relatively strong interactions between the PVA fibers and PU fibers. Therefore, the stress could be effectively transferred among the PVA fibers when the PVA/PU composite films were extended, and the mechanical strength of composite films was improved. Moreover, the elongation at break of the composite films was also improved dramatically because of the good flexibility of the PU resin. The fabricated composite films are of improved mechanical performance and good biocompatibility. They are of great potential in biomedical applications, including tissue-engineering, wound-dressing and controlled drug release.

poly(vinyl alcohol)(PVA); polyurethane(PU); dual-jet; electrospinning; mechanical performance

2015-11-25；

2015-12-28

國家自然科學(xué)基金資助項目(21204016);安徽省自然科學(xué)基金資助項目(1508085ME107)

魏士明(1989-),男,安徽滁州人,合肥工業(yè)大學(xué)碩士生; 楊 文(1973-),女,安徽合肥人,博士,合肥工業(yè)大學(xué)副教授,碩士生導(dǎo)師.

10.3969/j.issn.1003-5060.2016.12.021

O63-0

A

1003-5060(2016)12-1698-07