表面疏水化热塑性淀粉材料的性能

用含有异氰酸酯基的预聚体对热塑性淀粉材料（TPS）表面进行了疏水化处理。研究了除层与TPS表面的反应性、涂层的疏水性能以及力学性能。红外光谱（IR）分析结果表明，预聚体与基体TPS之间进行了反应,为反应性涂层；TDI／蓖麻油体系涂层样品表面的疏水性能与TPS相比有很大的改善，而TDI／PEG涂层样品表面的疏水性差；另外，涂层对材料起到一定的增强作用。     

热塑性淀粉／反应性聚酰胺复合膜的力学性能研究

为了提高淀粉基复合膜的干/湿态力学性能,将反应性聚酰胺(RPA)、烷基烯酮二聚体(AKD)与热塑性玉米淀粉(St)复合后采用浇铸法制备新型疏水化复合膜。研究了RPA、AKD及丙三醇(GL)对复合膜力学性能的影响。结果表明:反应性聚酰胺、烷基烯酮二聚体能够明显改善淀粉基复合膜的力学性能,尤其是湿态复合膜的拉伸强度。复合膜的较佳组成为St:GL:RPA:AKD=10．0:(3．0-4．0):(4．0-5．0):(0．5-0．7);复合膜的干态拉伸强度和断裂伸长率分别可以达到12．10MPa和45．70％以上,湿态拉伸强度和断裂伸长率则分别可以达到5．40MPa和30．0％以上。     

蒙脱土对热塑性淀粉结晶和力学性能的影响

用熔融挤出方法制备的甘油塑化热塑性淀粉(GTPS)/蒙脱土(MMT)复合材料,可以有效抑制GTPS长时间放置的结晶行为,提高其力学性能。不同相对湿度下复合材料、GTPS、淀粉的X ray衍射说明,MMT对GTPS结晶有抑制作用;力学测试表明,随着w(MMT)=0%提高到30%,复合材料最大应力达到27 31MPa,应变从85 3%下降到17 8%,杨氏模量达到206 7MPa,断裂能从1 921N·m下降到1 723N·m。红外(FTIR)谱图显示复合材料中淀粉分子的碳氧(C—O)基团向高波数移动,蒙脱土中可反应性羟基(OH)向低波数移动。这表明蒙脱土分子可反应OH和淀粉分子OH之间有氢键形成,使GTPS中淀粉分子之间氢键难以形成,蒙脱土在复合材料中起到阻隔剂的作用,是抑制GTPS结晶的主要原因;扫描电子显微镜(SEM)显示,蒙脱土均匀分散在GTPS中,提高了材料力学性能。     

结晶行为对热塑性淀粉材料性能的影响

分析研究了儿种淀粉和热塑性淀粉的结晶性能、流变性能、力学性能以及含水量对热塑性淀粉的重结晶性能以及对材料的影响。结果表明:虽然几种淀粉的结晶度不同结晶类型不同,但淀粉的塑化性能、拉伸强度、断裂伸长率与结晶度、结晶类型无关,只与淀粉分子中直链分子链的含量有关、与淀粉的相对分子质量有关。实验结果还表明:热塑性淀粉在放置时一间内会出现重结晶现象,结晶的晶型有所转变;结晶度呈现增大趋势,其变化速度与热塑性淀粉中水含量有关,水可以促进热塑性淀粉的重结晶,甘油可以减小重结晶速度。     

低熔点共聚酰胺/热塑性淀粉共混材料的制备及性能研究

本文将热塑性淀粉与低熔点共聚酰胺以不同的比例共混挤出，得到增强的热塑性淀粉材料。测试了样品的流变性能、模拟实际应用（85℃热水中浸泡一定时间后测试机械性能的变化）的耐水性能，并通过动态热机械分析（DMA）和扫描电子显微镜（SEM）表征了共混物各组分的相容性。结果表明，共混物各组分间有较好的相容性，共聚酰胺对热塑性淀粉材料具明显的增强作用。经热水浸泡后，共混物的保留强度与单纯热塑性淀粉相比均有不同程度的提高，尤其共聚酰胺含量大于30％时，耐水性显著增强。通过流变性能分析，共聚酰胺的加入使流动活化能下降，增加了共混物的流动性。     

淀粉的热塑性研究

通过在淀粉中加入增塑剂，制备热塑淀粉，研究了3种不同淀粉－玉米淀粉，木薯淀粉和可溶性淀粉的增塑性情况，研究了甘油、乙二醇、山梨醇、聚乙烯醇4种塑剂的增塑效果，不同的淀粉品种及不同增塑剂的产品性能有所不同。在显微镜下观察到，淀粉经塑化后，次价键断裂，晶区被破坏，使淀粉具备了热塑性，可以加工成薄膜。     

淀粉胶膜增韧方法及其增塑剂

本文阐述了淀粉胶膜脆性的本质，提出增韧的几种方法，指出水做为淀粉胶膜增塑剂是最经济和有效的途径。     

Formamide as the plasticizer for thermoplastic starch

As a novel plasticizer, formamide was tested in thermoplastic starch (TPS), in which native cornstarch granules were proved to transfer to a continuous phase by scanning electron microscope (SEM) and the hydrogen bond interaction between plasticizer and starch was proved by Fourier transform infrared (FTIR) spectroscopy. Mechanical tests showed that tensile strength and Young's modulus of formamide‐plasticized TPS (FPTPS) were lower than glycerol‐plasticized TPS (GPTPS) and elongation at break and energy break were higher. The effect of formamide and glycerol on the retrogradation of TPS was studied using X‐ray diffractometry. Formamide could effectively restrain the starch retrogradation at three different relative humidity (RH) environments, because it could form the more stable hydrogen bonds with the starch hydroxy group than glycerol. From these results, we found that the elongation at break, energy break, and the retrogradation of TPS were ameliorated by formamide. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1769–1773, 2004     

Preparation and Properties of Biodegradable Thermoplastic Starch/Clay Hybrids

Biodegradable thermoplastic starch (TPS)/clay hybrids were prepared by melt intercalation. Three organically modified montmorillonite (MMT) with different ammonium cations and one unmodified Na⁺ MMT (Cloisite Na⁺) were used. Cloisite Na⁺ showed the best dispersion in the TPS matrix. It was observed that the TPS/Cloisite Na⁺ hybrid showed an intercalation of TPS in the silicate layer due to the matching of the surface polarity and interactions of the Cloisite Na⁺ and the TPS, which gives higher tensile strength and better barrier properties to water vapor as compared to the other TPS/organoclay hybrids as well as the pristine TPS. It was found that the dynamic mechanical properties of the TPS/clay hybrids were also affected by the polar interactions.     

淀粉/PVA生物降解材料的热塑性研究

将聚乙烯醇(PVA)、淀粉、增塑剂在Hakke流变仪中共混制备了热塑性淀粉/PvA材料,研究了2种PVA-PVA1799、PVA1788,2种淀粉-玉米淀粉、木薯淀粉的热塑性情况;比较了甘油、乙二醇、乙酰胺3种增塑剂的增塑效果.结果表明:采用合适的增塑剂与适当的PVA、淀粉组合可以使PVA/淀粉共混体系在高温下热塑成型...     

淀粉基热塑性生物降解塑料的研制

以干法改性淀粉为主要原料 ,通过由V (甘油 )∶V (乙二醇 ) =1∶2组成的复合增塑剂的增塑 ,添加增强剂PX和增溶剂EAA ,共混后可研制出淀粉基热塑性生物降解塑料。研究表明 ,该塑料中w (改性淀粉 ) =5 0 %～ 70 % ,其他添加成分也均可生物降解 ,具有良好的机械性能。生物降解实验显示其在 90d后降解率达 5 0 %以上     

热塑性淀粉材料降解行为的研究

研究增塑剂对热塑性淀粉塑料的影响。实验表明：水及甘油可以作为淀粉的增塑剂,但是甘油增塑淀粉对空气中水分的敏感性更大。     

淀粉的塑化研究进展

淀粉具有良好的生物降解性能,但淀粉分子中含有大量的羟基,存在较强的氢键,使得淀粉不宜直接用熔融法热塑挤出加工,因此淀粉的塑化是淀粉塑料生产的关键。对以加入增塑剂的热塑性增塑方法进行了综述,并进一步探讨了淀粉塑化的机理。     

Thermoplastic Starch Nanocomposites Reinforced with Cellulose Nanocrystal Suspensions Containing Residual Salt from Neutralization

Sulfuric acid-catalyzed hydrolysis of cellulose commonly isolates cellulose nanocrystals (CNCs). Neutralizing the reactant solution with sodium hydroxide facilitates efficient downstream processing, but residual salt remains in the product. This study examines the reinforcing effects of CNCs from suspensions that contain residual salt on the mechanical properties of thermoplastic starch nanocomposites. By reinforcing starch films with up to 5 wt% CNCs, stiffness and strength are improved by 118% and 79%, respectively, indicating a good dispersion of CNCs in the starch matrix. Compared to nanocomposites incorporating salt-free CNCs, the remaining salt has no significant impact on the material's mechanical performance. The results indicate great potential of CNCs containing residual salt as biobased, low-cost nanofiller in hydrophilic polymer matrices.     

Thermoplastic Starch and Drug Delivery Capsules

The thermoplastics processing of natural hydrophilic polymers in the presence of water is a recent development with very wide possible applications. Eventually, oil-based polymer materials could be replaced in many applications by inexpensive, natural products from renewable resources. As with conventional thermoplastics, hydrophilic polymer melts may be processed by injection-moulding and extrusion. The present contribution focuses on the injection-moulding of potato starch. The basis of the processing is described. In addition, the rheological behaviour of the starch/water melts during processing is analysed quantitatively to give apparent melt viscosities. The mechanical properties of moulded starch materials and the drug delivery behaviour of starch capsules are discussed. © 1997 SCI.     

不同直链含量热塑性淀粉的制备及性能研究

利用转矩流变仪,以丙三醇为增塑剂对不同来源的淀粉进行改性制备热塑性淀粉（TPS）。采用X射线衍射仪（XRD）、热重分析仪（TG）、水接触角测量仪、傅里叶变换红外光谱仪（FTIR）和扫描电子显微镜（SEM）等对获得的热塑性淀粉进行了表征。结果表明,4种热塑性淀粉均含有颗粒状和颗粒状碎片,并且在热塑性木薯淀粉中所含比例更高;淀粉在增塑过程中达到稳态的扭矩依次为木薯淀粉（23 N·m）>玉米淀粉（21 N·m）>马铃薯淀粉（17.8 N·m）>蜡质玉米淀粉（15.2 N·m）,这与不同种类来源淀粉的直链淀粉比例差异直接相关;不同类型的淀粉与增塑剂形成氢键的能力存在差异,蜡质玉米淀粉的能力最强;4种热塑性淀粉的亲水性依次为热塑性木薯淀粉（75.9 °）>热塑性玉米淀粉（69.2 °）>热塑性马铃薯淀粉（67.9 °）>蜡质玉米淀粉（64.9 °）。     

马来酸酐对热塑性淀粉／聚乙烯相容性的影响

研究了在引发剂作用下，马来酸酐作为热塑性淀粉(TPS)／聚乙烯共混体系的增容剂，采用淀粉的热塑化与提高聚乙烯的相容性在单螺杆挤出机里同时完成的工艺。实验结果表明，在引发剂作用下，马来酸酐的加入提高了共混物中淀粉颗粒在聚乙烯中的分散性及共混体系的力学性能以及热稳定性，流变性能分析表明共混体系具有可加工性能。     

Study of the Plasticizer Effect and Characterization on Diverse Pseudo-Thermoplastic Starch Biodegradable Films

Recently, pseudo-thermoplastic starch (PTS) has been developed to replace industrial plastics because of its advantage in biodegradability. In this study, potato, corn, and wheat starches, which have been modified into PTS biodegradable films by glycerol plasticization, were investigated. For the evaluation of the suitable compositions on PTS, we focus on analysis of the plasticizer effect and characterization. As the results show that the strength and modulus of pseudo-thermoplastic potato starch (PTP) film were respectively, 12.7 and 59.6 MPa, with lower gelatinization temperature (60°C), and the thermal processibility was better than other starches. It is beneficial for the production and application of biodegradable materials.     

Electrically Triggered Actuation of Plasticized Thermoplastic Polyurethane Gels

Thermoplastic polyurethanes (TPUs) are copolymers with hard and soft segments. They have excellent physical properties and good biocompatibility. In particular, their shape memory properties and compatibility with plasticizers make TPU gels suitable for use as soft actuator materials. In this work, a plasticizer, dibutyl adipate (DBA), is added to four types of TPU to form gels. All the TPUs form transparent soft gels with different DBA contents. Their dielectric and mechanical properties are significantly improved by DBA addition, and the TPUs are changed from insulators to electrical actuation materials. Polyether TPU/DBA gels show the most significant changes. The bending distance of a TPU/6DBA gel tip (dimensions 20 × 5 × 0.3 mm³) is about 15 mm when the gel is sandwiched between soft electrodes and an electric field of less than 3 V μm^–1 is applied. The developed materials show large deformations at low energies, and will make a significant contribution to the field of actuation materials. It is believed that TPU/DBA gels can be used as photovoltaic, dielectric, artificial muscle, robotic, and other smart materials.

     

可降解热塑性淀粉/层状硅酸盐纳米复合材料的研究进展

热塑性淀粉/层状硅酸盐纳米复合材料具有常规热塑性淀粉材料所没有的结构、形态以及较常规热塑性淀粉材料具有更优异的机械性能、耐热性能和气体、液体阻隔性能等而显示出重要的科学意义和应用前景.本文综述了目前国内外热塑性淀粉/层状硅酸盐纳米复合材料的发展现状,并对其应用前景进行了展望.