淀粉/聚丙撑碳酸酯/马来酸酐酯化淀粉完全生物降解塑料的研究

制备了马来酸酐酯化淀粉,红外光谱分析证明淀粉进行了酯化反应,讨论了影响酯化淀粉接枝率的各种因素,确定了马来酸酐酯化淀粉的最佳反应条件。同时制备了淀粉/聚丙撑碳酸酯/马来酸酐酯化淀粉完全生物降解塑料,研究了酯化淀粉加入量对共混物的力学性能和微观形态的影响。结果表明:加入马来酸酐酯化淀粉后,改善了淀粉和聚丙撑碳酸酯的相容性,共混物的力学性能有很大提高。     

聚甲基乙撑碳酸酯/聚丁二酸丁二醇酯共混体系性能研究

采用熔融共混法制备了聚甲基乙撑碳酸酯/聚丁二酸丁二醇酯(PPC/PBS)复合材料,通过力学性能、DSC、TG研究了PBS用量对PPC/PBS共混体系力学性能、结晶性能、热稳定性的影响。结果表明:PBS的加入提高了PPC/PBS共混体系的拉伸强度、缺口冲击强度和热稳定性。     

聚丁二酸丁二醇酯与聚乳酸共混型全生物降解材料的结构和性能研究

通过机械共混法,使聚丁二酸丁二醇酯(PBS)、聚乳酸(PLA)熔融共混,制备了一种完全生物降解塑料。用红外光谱(FTIR)法、DSC(DifferentialScanningCalorimetry)法、扫描电镜法(SEM)及力学测试等手段研究了不同组分配比情况下共混物的结构、热性能以及力学性能变化。并研究了聚丙撑碳酸亚丙酯(PPC)的加入对共混体系性能的影响。结果表明:随着PBS含量的增加,PBS/PLA共混体系的拉伸强度降低不多,而断裂伸长率显著提高。而PPC的加入能够提高共混体系的相容性并显著提高体系的韧性。     

聚(3-羟基丁酸酯-共-4-羟基丁酸酯)/马来酸酐共混物性能的研究

采用熔融共混方法制备了一系列聚(3-羟基丁酸酯-共-4-羟基丁酸酯)/马来酸酐(MA)的共混物。研究了MA含量对共混物力学性能的影响,并且采用差示扫描量热仪和热失重分析仪对共混物热性能的变化进行了研究。结果表明,MA的加入有效改善了聚(3-羟基丁酸酯-共-4-羟基丁酸酯)的力学性能和热稳定性,拓宽了其加工窗口,其中加入0.5份MA就可将共混物的起始热分解温度提高19.31℃。同时,MA能够改善3-羟基丁酸酯微区和4-羟基丁酸酯微区的相容性。     

聚苯乙烯改性聚丙撑碳酸酯的制备和表征

在聚苯乙烯(PS)的黏流温度以下制备了聚丙撑碳酸酯(PPC)和PS的共混物,研究了配比对PPC/PS共混物的热降解、形貌、力学性能和水蒸气阻隔性的影响。结果表明,共混物的黏度随PS含量增加而增大。PS促进了PPC的热降解。PS质量分数为50%～70%时,共混物为共连续结构。其他配比下,共混物呈海岛分相,分散相呈片层状。随PS含量的提高,共混物的弹性模量、拉伸强度和洛氏硬度提高,断裂伸长率降低。38℃下,共混物的水蒸气渗透率随PS含量的增加而降低,而在20℃下,变化趋势相反。当PS质量分数为50%时,共混物的水蒸气渗透率在20～38℃内不随温度改变。     

聚己内酯对聚乳酸/PBAT共混物增容作用的研究

研究了聚己内酯(PCL)作为增容剂对聚乳酸(PLA)与聚己二酸-对苯二甲酸丁二酯(PBAT)的共混物力学性能、热性能、动态力学性能和相容性的影响。结果表明,加入PCL可以改善PLA与PBAT的相容性,提高共混物的冲击强度、拉伸强度和拉伸弹性模量;在PCL含量为2份时共混物两相之间具有良好的相容性。     

制备方法对聚乳酸/聚丙撑碳酸酯性能的影响

通过熔融共混法和溶液浇注法制备了聚丙撑碳酸酯(PPC)与聚乳酸(PLA)的共混物。采用转矩流变仪、差示扫描量热仪、扫描电子显微镜、紫外可见近红外分光光度计等对共混物进行了表征,研究了共混方法对材料性能的影响。实验结果表明:PLA/PPC为部分相容性共混物,常温下放置体系会发生物理老化;PPC的加入使共混物的水蒸气阻隔性提高,随着温度的升高,共混物的水蒸气阻隔性明显降低,特别是PPC含量多的组分;PPC的加入还使共混物拉伸强度和杨氏模量降低,断裂伸长率提高。熔融共混会造成PPC和PLA的降解,降低体系黏度;相对于溶液浇注制备的共混物,其断裂伸长率较低,水蒸气阻隔性较好。     

热塑性聚氨酯/氯化聚乙烯共混物形态与性能的影响因素

采用机械共混法制备了热塑性聚氯酯(TPU)/氯化聚乙烯(CPE)共混物,考察了共混比(质量比,下同)对共混物加工性能、力学性能及微观形态的影响.研究了热稳定剂种类对共混物力学性能、热稳定性的影响.结果表明.加入CPE可以明显改善TPU的加工性能;在TPU与CPE的共混比分别为70/30和60/40时,TPU/CPE共混物具有较好的力学性能;TPU与CPE共混,二者的相容性较好,热稳定性均得到提高;自制环保型钙锌复合稳定剂的综合稳定作用较好,且所得共混物的力学性能也好.     

超支化聚（酰胺-酯）／ABS／聚氯乙烯共混体系相容性研究

研究了超支化聚(酰胺-酯)(HBP)对ABS/聚氯乙烯(ABS/PVC)共混体系的增容作用。讨论了HBP用量对ABS/PVC(80/20)和相同量HBP对不同比例ABS/PVC力学性能的影响。实验结果表明ABS/PVC共混物中加入HBP,可以有效改善共混体系的相容性;加入2份HBP时,ABS/PVC(80/20)共混物拉伸强度达到最大值,继续增加HBP,共混物拉伸强度快速下降,而共混物冲击强度单调下降;不同比例ABS/PVC中加入2份HBP共混物拉伸强度比未加入HBP共混物拉伸强度增加,但共混物冲击强度减小。扫描电子显微镜研究结果证明了HBP增强了ABS/PVC的界面黏结作用,减小了共混体系的相分离程度。     

聚碳酸亚丙酯/壳聚糖熔融共混改性研究

采用熔融共混法将聚碳酸亚丙酯(PPC)与壳聚糖(CS)共混改性,研究了CS含量对PPC/CS共混物相容性、玻璃化转变温度(Tg)、热失重温度和拉伸性能的影响,并探讨了CS改性PPC的作用机理。结果表明:PPC与CS的共混属于简单物理共混,CS对PPC的Tg影响不大,但可显著提高PPC基体的耐热性能,扩大复合材料的加工温度范围。同纯PPC相比,PPC/CS共混物的TGA曲线向高温区偏移,共混物的5%分解温度(T-5%)较PPC提高了51⁵9℃,其50%分解温度(T-50%)提高了1259℃,其50%分解温度(T-50%)提高了12²1℃;另外,共混物的TGA曲线只存在一个高温区的失重台阶,这是由于CS的引入抑制了PPC在低温区的解拉链式降解,因而只有高温区的无规降解发生。此外,随着CS含量的增加,PPC/CS共混物的拉伸强度不断增大,当CS含量增至20%时,材料的拉伸强度由纯PPC的4.7 MPa上升至12.5 MPa。     

Macroporous chitosan/carboxymethylcellulose blend membranes and their application for lysozyme adsorption

The adsorption of lysozyme was investigated with novel macroporous chitosan (CS)/carboxymethylcellulose (CMC) blend membranes. The CS/CMG blend membranes were prepared by a simple solution‐blending method with glutaraldehyde as a crosslinking agent for CS and with silica particles as porogens. The CS/CMC blend membranes were insoluble in aqueous media when the CMC concentration in the membranes did not exceed 30 mol %. The protein adsorption on these membranes from aqueous solutions containing different amounts of lysozyme at different pHs was investigated in batch systems. The results showed that the lysozyme adsorption capacity had a maximum at pH 9.2, and this indicated that the CS/CMC blend membranes could act as cation‐exchange membranes. Moreover, the blend membranes showed the best adsorption properties for lysozyme when the CMC concentration was 20 mol %. In addition, the lysozyme adsorption capacity of the blend membranes increased with an increase in the initial lysozyme concentration and the adsorption temperature. The maximum adsorption capacity of the macroporous CS/CMC blend membranes was as high as 240 mg/g (170 mg/mL), and more than 95% of the adsorbed lysozyme was desorbed in a pH buffer at 11.8. The blend membranes also demonstrated good reusability after several adsorption–desorption cycles. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1267–1274, 2005     

PPC/PDAP共混膜的制备和性能

将过氧化二异丙苯(DCP)置于特定温度下,引发邻苯二甲酸二烯丙酯(DAP)在聚碳酸亚丙酯(PPC)溶液中聚合,制备得到聚碳酸亚丙酯/聚邻苯二甲酸二烯丙酯(PPC/PDAP)共混膜。采用红外光谱仪(FTIR)、X射线衍射仪(XRD)、差示扫描量热仪(DSC)、热重分析仪(TGA)、万能试验机和水蒸气透过率测试仪对共混膜的红外吸收、结晶性、热、力学和阻隔性能进行了表征。结果表明,通过DAP的聚合,提高了PPC的结晶性,使PDAP在PPC基体中形成交联网络,提高了共混膜的热、力学和阻隔性能。相比纯PPC,当DAP含量为20%时,共混膜的玻璃化转变温度和拉伸强度分别提高了5.3℃和266%;当DAP含量为40%时,共混膜的失重5%热分解温度提高了50.9℃,透湿系数下降了25%,因此,阻隔性能得到了提升。     

Development of biopolymer composite films based on chicory extract reinforced polyvinyl alcohol/chitosan blend via green approach for flexible optoelectrical devices

Biopolymer blend composite films based on polyvinyl alcohol (PVA) and chitosan (CS) incorporated with varying amounts of chicory extract (CE) have been developed by the green solution casting technique. The impact of CE content on structural, thermal, mechanical and electrical properties was thoroughly examined. The existence of intermolecular interactions in the blend composite was confirmed by Fourier-transform infrared and ultraviolet spectroscopy. The x-ray diffraction pattern proved the successful preparation of PVA/CS/CE composite film. The scanning electron microscopy images of the composites showed shape and grain size for the different bio-filler contents. The thermal transition temperature of the blend composites was significantly improved by the addition of CE extract deduced from differential scanning calorimetry. The dielectric study showed that the permittivity remarkably increases with decreasing frequency and maximum dielectric constant was observed for 15 wt% loading. The activation energy obtained from the AC conductivity decreased as the temperature increased. The addition of CE extract improved the hardness and tensile strength of the PVA/CS blend composite in comparison with a pristine pure blend. The controllable mechanical, thermal, optical, and electrical characteristics of the PVA/CS blend composite suggest that it might be an attractive optical material for the advancement of futuristic flexible-type optoelectronic and energy storage systems.     

丝素/羧甲基壳聚糖共混膜的结构性能探讨

将含有甘油和戊二醛的丝素与羧甲基壳聚糖按一定比例混合,制得丝素/羧甲基壳聚糖共混膜,对共混膜的结构与性能进行了探讨。结果表明:随着羧甲基壳聚糖含量的增加,共混膜的透气率增大,加入交联剂戊二醛有效地改善了共混膜的力学性能,但其透气率有所降低;当丝素与羧甲基壳聚糖的质量比为4/1时,共混膜的断裂强度最大,力学性能较好,共混膜相容性较好,其断面光滑、致密。制备丝素/羧甲基壳聚糖共混膜的较佳条件为:丝素中的甘油质量分数为15%,戊二醛质量分数为0.075%,丝素与羧甲基壳聚糖质量比为4/1。     

添加剂改性玉米醇溶蛋白复合膜的制备与表征

采用流延法制备高含量玉米醇溶蛋白（Zein）的Zein/壳聚糖（CS）复合膜，通过复合添加剂〔m(甘油)：m(聚乙二醇400)=1:1〕对Zein/CS复合膜共混改性，研究复合添加剂添加量（以总溶液质量计，分别为0、0.5%、1.0%、1.5%、2.0%）对薄膜的力学、光学和热学性能等的影响，并通过SEM、FTIR对薄膜形貌和结构变化进行表征。结果表明，复合添加剂通过削弱Zein和CS之间的分子间作用力，达到增塑效果，薄膜综合机械性能有所改善，随着复合添加剂添加量的升高，薄膜断裂伸长率逐渐增强，拉伸强度呈下降再上升的趋势；水蒸气透过率逐渐增加，水接触角逐渐减小，薄膜亲水性随之增强。与不含复合添加剂的薄膜（ZC-0）相比，当复合添加剂添加量为1.5%时，复合膜（ZC-1.5）的抗拉强度降低了27.40%，断裂伸长率增长了39.87%，水蒸气透过率上升了29.10%。通过SEM和DSC观察，添加复合添加剂改性后，改善了Zein和CS之间的相容性，制备的薄膜表面更加平整光滑。综合性能可得，制备高含量Zein的Zein/CS复合膜，复合添加剂浓度为1.5%时，薄膜性能最优。并在含有1.5%复合添加剂的Zein/CS薄膜中添加了一定量的姜黄素，据测定其能够有效提高薄膜的抗氧化性能至55.18%。     

Studies on the blends of CO2 copolymer. IV. Natural rubber/poly(propylene carbonate) systems

The blends of a carbon dioxide copolymer, poly(propylene carbonate)(PPC) with natural rubber (NR), were prepared and their mechanical properties and morphology were studied. The optimum formulation blend was obtained by orthogonal experiments. The tensile strength of the blend containing 30 phr PPC was 18.9 MPa, with an elongation at break of 755%. The factors such as PPC and dicumyl peroxide content, PPC molecular weight, sulfur content, curing time, and curing temperature responsible for controlling the mechanical properties were discussed. Transverse electron micrographs showed a two‐phase structure for this blend. Gel content data revealed that PPC was crosslinked. The phase stability of PPC in the blend improved because of the interpenetrating new work structure. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2140–2144, 2002     

Biodegradable PPC/(PVA-TPU) ternary blend blown films with enhanced mechanical properties

Biodegradable films of poly(propylene carbonate)/poly(vinyl alcohol)-thermoplastic polyurethane [PPC/(PVA-TPU)] ternary blends were successfully prepared by melting blending method. The mechanical properties of poly(propylene carbonate) blown film were greatly improved by blending PPC with PVA-TPU. In order to afford the melt processing of PVA, the PVA-TPU binary blend was firstly prepared using thermoplastic polyurethane as a polymeric plasticizer. The rheological behavior, mechanical properties and morphology of these blends were studied. Considering its melt viscosity and thermally processing temperature, the PVA-50%TPU, as a modifier, was blended with PPC to prepare PPC/(PVA-TPU) ternary blend. SEM observation revealed a basic one-phase morphological structure with very good interfacial adhesion between the extremely blurred PPC and PVA-TPU two components. Meanwhile, the miscibility of the ternary components was verified by only one glass-transition temperature obtained from DMA tests. The tensile strength and tear strength of PPC/(PVA-TPU) blown films were determined at different temperatures. The results demonstrate that the mechanical properties of PPC/(PVA-TPU) films were enhanced dramatically at low temperature when compared with neat PPC. At room temperature, PPC/30 %(PVA-50%TPU) blown film exhibited a tensile strength of 26 MPa, and an elongation at break of 484.0 %. Its tear strength in the take-up direction is 124.1 kN/m, and the one in machine direction is 141.9 kN/m. At a low temperature of 0 °C, PPC/30 %(PVA-50%TPU) exhibited a tensile strength of 40.7 MPa and tear strength of 107 kN/m, which are 153 % and 142 % of those of neat PPC respectively. The blending of PPC with the PVA plasticized with TPU provides a practical way to extend the application of the new biodegradable polymer of PPC in the area of blown films.     

Studies of chitosan. I. Preparation and characterization of chitosan/poly(vinyl alcohol) blend films

Various blending ratios of chitosan/poly (vinyl alcohol) (CS/PVA) blend films were prepared by solution blend method in this study. The thermal properties and chemical structure characterization of the CS/PVA blend films were examined by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), and Fourier transform infrared (FTIR). Based upon the observation on the DSC thermal analysis, the melting point of PVA is decreased when the amount of CS in the blend film is increased. The FTIR absorption characteristic is changed when the amount of CS in the blend film is varied. Results of X‐ray diffraction (XRD) analysis indicate that the intensity of diffraction peak at 19° of PVA becomes lower and broader with increasing the amount of CS in the CS/PVA blend film. This trend illustrates that the existence of CS decreases the crystallinity of PVA. Although both PVA and CS are hydrophilic biodegradable polymers, the results of water contact angle measurement are still shown as high as 68° and 83° for PVA and for CS films, respectively. A minimum water contact angle (56°) was observed when the blend film contains 50 wt % CS. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Bio‐nanocomposite films based on cellulose nanocrystals filled polyvinyl alcohol/chitosan polymer blend

Bio‐nanocomposite films based on polyvinyl alcohol/chitosan (PVA/CS) polymeric blend and cellulose nanocrystals (CNC) were prepared by casting a homogenous and stable aqueous mixture of the three components. CNC used as nanoreinforcing agents were extracted at the nanometric scale from sugarcane bagasse via sulfuric acid hydrolysis; then they were characterized and successfully dispersed into a PVA/CS (50/50, w/w) blend to produce PVA/CS–CNC bio‐nanocomposite films at different CNC contents (0.5, 2.5, 5 wt %). Viscosity measurement of the film‐forming solutions and structural and morphological characterizations of the solid films showed that the CNC are well dispersed into PVA/CS blend forming strong interfacial interactions that provide an enhanced load transfer between polymer chains and CNC, thus improving their properties. The obtained bio‐nanocomposite films are mechanically strong and exhibit improved thermal properties. The addition of 5 wt % CNC within a PVA/CS blend increased the Young's modulus by 105%, the tensile strength by 77%, and the toughness by 68%. Herein, the utilization of Moroccan sugarcane bagasse as raw material to produce high quality CNC has been explored. Additionally, the ability of the as‐isolated CNC to reinforce polymer blends was studied, resulting in the production of the aforementioned bio‐nanocomposite films with improved properties. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42004.