热塑性淀粉加工过程的控制参数及塑化程度的表征方法

在介绍热塑性淀粉塑料加工原理的基础上,提出特殊机械能可以作为描述热塑性淀粉塑化过程的控制参数;并对表征热塑性淀粉塑化程度的各种方法进行了总结和评述。     

全淀粉热塑性塑料的研制

为解决塑料污染环境的问题，以淀粉为原料，添加极少量可降解的增塑剂等助剂，研制了全淀粉热塑性塑料。淀粉经过增塑后，具备了热塑性加工的可能性。全淀粉塑料几乎可用所有的塑料加工方法进行加工。玉米含量为９０％的热塑性淀粉塑料薄膜，性能基本能达到同类应用传统塑料的性能标准。不同淀粉品种及不同含水量的产品性能有所不同。全淀粉塑料在加工时必须含有一定量的水份，含水量以８％～１５％为宜。但产品因吸水又会导致物理性能变差。全淀粉塑料降解性能非常好，通过控制配方，可达到三个月，半年及一年的不同降解速率。     

全淀粉热塑性塑料及研究

主要阐述了热塑性淀粉（TPS）的塑化机理、热塑性淀粉的性质以及近年来国内外关于热塑性淀粉的研究成果。国内许多学者研究了增塑剂的种类和数量对热塑性淀粉性能的影响，淀粉改性后再塑化以及寻找新的增塑剂，但国内这种技术还处在研究阶段，还没有关于产业化和产品应用方面的报道；国外学者还研究了直链淀粉含量对热塑性淀粉性能的影响，研究了用淀粉的超小晶体作为增强剂可以提高热塑性淀粉的强度。     

琥珀酸钠/二甘醇对淀粉的协同增塑作用

采用琥珀酸钠和二甘醇作为增塑剂制备热塑性淀粉复合膜，研究了琥珀酸钠/二甘醇质量比对热塑性淀粉复合膜结构、力学性能、耐老化性、透光性和吸湿性的影响。结果表明，琥珀酸钠或二甘醇单独增塑的淀粉膜易老化和吸湿，但两组分的复配对淀粉膜的结构和性能有协同作用。琥珀酸钠/二甘醇质量比为10/15时的热塑性淀粉膜韧性、透光性和耐老化能力最佳，吸湿率最低，其膜放置3和60 d时断裂伸长率分别为76.1%和61.6%。这可能与淀粉、琥珀酸钠和二甘醇的相容性较好有关。琥珀酸钠、二甘醇的复配为热塑性淀粉的加工和应用提供了可能。     

全生物降解淀粉塑料的研究进展

介绍了全生物降解淀粉塑料的研究目的及意义,综述了热塑性淀粉塑料、淀粉/可降解聚合物共混物和淀粉/天然高分子共混物3种全生物降解淀粉塑料的研究进展,包括热塑性淀粉塑料的生产原理和优势、增塑剂的选择与配比对热塑性淀粉塑料的影响、淀粉与聚丁二酸丁二醇酯、聚乙烯醇、聚己内酯、聚乳酸、纤维素、木质素、蛋白质等共混后的性能。最后分析了全生物降解淀粉塑料研究中存在的问题,并对全生物降解淀粉塑料进行了展望。     

微细化淀粉在塑性生物降解塑料中的应用研究

利用红外光谱和实验，研究了微细化交联淀粉对热塑性淀粉对热塑性生物降解塑料材料性能的影响，结果表明，微细化交联淀粉的平均粒径可以达到3μm。经偶联剂处理，微细化交联淀粉的疏水性是到提高。以此微细化交联淀粉为原料制备的热塑性降的降解塑料在淀粉质量分数高达40％的同时，拉伸强度达62.3MPa，断裂伸长率为289％，48h质量吸水率为0．31％。在120d内该塑料土埋生物降解率达到50％以上。     

可生物降解淀粉基共混物的研究

将淀粉塑料体系分为淀粉／聚烯烃的共混,淀粉／可生物降解聚合物和热塑性淀粉三类。综述了近年来国内外淀粉基降解塑料的研究现状和进展,并对其发展动态进行了简要介绍。     

热塑性淀粉的制备与性能研究

以丙三醇/甲酰胺和丙三醇/尿素为增塑剂采用双辊筒炼塑机制备热塑性淀粉。研究了设备的加工特点和复合增塑剂的不同配比对热塑性淀粉力学性能、熔体流动性的影响,并以偶联剂对淀粉进行表面处理,比较其对淀粉的疏水化改性和抑制回生的效果。     

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。     

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 °）。     

新型热塑性淀粉制备与性能研究

以甘油为增塑剂,制备了玉米和小麦两种热塑性淀粉。通过扫描电镜、拉伸强度以及含水率的表征等方法研究了分散时间、糊化温度及糊化时间对淀粉性能的影响。结果表明:在最佳制备条件下,玉米和小麦两种热塑性淀粉形态为均一的连续相,并且拉伸强度均可达到15MPa。     

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。     

New breathable films using a thermoplastic cross‐linked starch as a porogen

Breathable films, which find in variety of product applications, are conventionally made using mineral porogens such as calcium carbonate (CaCO₃). This article addresses a novel biodegradable and highly breathable film without inorganic porogens. Unexpectedly, a thermoplastic cross‐linked natural polymer (corn starch) was used successfully to create tortuous passages for film breathability. This concept was demonstrated using two types of thermoplastic cross‐linked corn starches as porogens and contrasted to control samples: native corn and chemically cross‐linked starches, respectively. The films discussed had increased breathability and mechanical properties relative to the control samples. The film morphology reveals that filler was irregular when thermoplastic starch or CaCO₃ was used. The difference in filler from chemically modified cross‐linked starch and thermoplastic cross‐linked starch was observable as well. It is believed that spherical particles provided by thermoplastic cross‐linked starch helps film debonding and porosity during the film stretch processes. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41016.     

剑麻纤维增强热塑性淀粉复合材料的制备及性能研究

为研究剑麻纤维增强的热塑性淀粉复合材料的制备工艺及热稳定性,以玉米淀粉为原料,先制得热塑性淀粉,再以剑麻纤维为骨架增强体制备剑麻纤维增强热塑性淀粉复合材料,通过正交试验优化制备工艺,DSC、TG/DTG、SEM分析其热稳定性及结构。正交试验表明,各因素对材料抗拉强度影响的主次顺序为纤维长度 >纤维用量 >模压成型温度 >填料用量;最佳工艺条件为纤维长度15mm、纤维用量35g、模压成型温度200℃、填料用量5g,此时材料的抗拉强度可达到4.45MPa。利用差示扫描量热分析和热重分析分别对热塑性淀粉及剑麻纤维复合材料的热稳定性进行了分析,结果表明,热塑处理提高了淀粉的熔融温度,有利于淀粉与纤维素羟基间的氢键结合,且热塑过程在一定程度上降低了淀粉的热稳定性;剑麻纤维复合材料的热降解过程主要发生在200~400℃温度区间。SEM分析显示最佳工艺条件下得到的复合材料具有较好的泡孔结构。     

Preparation and properties of thermoplastic pea starch using N,N‐bis(2‐hydroxyethyl)formamide as the plasticizer

N,N‐bis(2‐hydroxyethyl)formamide (BHF) was synthesized efficiently and used as a new plasticizer for pea starch to prepare thermoplastic starch (TPS). The hydrogen bond interaction between BHF and pea starch was proven by Fourier‐transform infrared (FT‐IR) spectroscopy. As detected by scanning electron microscope (SEM), pea starch granules were completely disrupted, and the homogeneous materials were obtained. The crystallinity of pea starch and BHF‐plasticized thermoplastic pea starch (BTPS) was characterized by X‐ray diffraction (XRD). Rheological properties of TPS were analyzed. The water resistance of BTPS was better than that of glycerol‐plasticized thermoplastic pea starch (GTPS). At RH 33%, the tensile strength of BTPS was higher than that of GTPS for TPS containing 30% plasticizer. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers     

PBAT/热塑性玉米淀粉共混改性对结构和力学性能影响

采用价格低廉的玉米淀粉为填充剂来改性生物可降解聚己二酸?对苯二甲酸丁二酯（PBAT），以降低PBAT价格，拓宽应用领域。首先采用丙三醇对玉米淀粉进行塑化，再采用双螺杆挤出机进行造粒获得热塑性淀粉（TPS）粒料，然后采用双螺杆挤出机和注塑机制备不同比例的PBAT/TPS样条，最后分析论文TPS含量对样条结构和力学性能的影响。结果表明，经丙三醇塑化后的淀粉含有大量的羟基，PBAT的结晶结构与PBT的相同，随着TPS含量的增加，PBAT的结晶完善程度逐渐降低，结晶温度向高温方向偏移，拉伸强度和断裂伸长率逐渐降低，而弹性模量有相反的趋势。     

On mechanical properties of sago starch/poly(ε‐caprolactone) composites

Four types of sago starch were incorporated into a poly(ε‐caprolactone) (PCL) matrix, native, predried, thermoplastic starch (TPS) granules and TPS. All systems were found to be phase‐separated. Tensile properties were obtained after formulation of various mixtures and processing of suitable test specimens. It was found that elongation at break of composites comprising native starch and thermoplastic starch decreases almost linearly with volume fraction of starch whereas tendencies to nonlinear dependencies were observed for predried and thermoplastic starch granules. Except for composites containing native starch, tensile strength was found to decrease linearly with volume fraction of starch. However, statistical analysis of the corresponding regression coefficients shows that the coefficients ruling the compostion dependence of tensile properties are not significantly different for the four starch types. One may conclude that in all cases, tensile properties decrease almost linearly with volume fraction and maximum volume fraction of starch loading is around 0.6. Scanning electron micrographs of fracture surfaces revealed weak interfacial adhesion between sago starch and the polymer matrix.     

Characterization of extruded film based on thermoplastic potato flour

Potato flour is abundant and less expensive than starch, though its major component is starch. It would therefore seem to be an attractive and viable source of biomass for biodegradable thermoplastic products. This study prepared thermoplastic potato flour (TPF) and thermoplastic potato starch (TPS) films by extrusion and investigated their properties. A mixture of glycerol and triethyl citrate (25−35% of total weight) was chosen for the plasticizer. Properties of the TPF film, such as mechanical properties, surface hydrophilicity, surface energy, moisture sorption isotherm, and glass transition temperature (T_g), were characterized and compared with TPS film. The results showed that TPF film was comparable to TPS film in many properties. The mechanical properties of the TPF film, including tensile strength, elongation at break, and tensile modulus, were similar in magnitude to TPS film. In addition, TPF film showed lower T_g and surface hydrophilicity, but higher surface wetting capacity than TPS film. Components other than starch in potato flour were believed to have had a plasticization effect on TPF properties. Overall, potato flour demonstrated a comparable capacity for manufacturing thermoplastic film similar to the more expensive starch feedstock. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012