The Effect of Plasticizers and Characterization on Formamide Pseudo-Thermoplastic Potato Starch Films using Solution Casting Method

Potato starch has great processability and formamide could provide excellent plasticization. Consequently, potato starch was modified into formamide pseudo-thermoplastic potato starch (FTPP) films in this study. For the evaluation of the optimum preparation on FTPP, we focus on analysis of the plasticizers effect and properties. The results show that the strength and elongation of FTPP-20 film were respectively 29.7 MPa and 6.7%, the melting temperature (129.8°C), melting heat (270.3 J/g), degradation temperature (295.0°C), and the characterization were better than plasticized potato starch with glycerol. It is advantageous on the production and application for the biodegradable materials.     

Preparation and properties of biodegradable thermoplastic starch/poly(hydroxy butyrate) blends

The vital differences using three types of thermoplastic starches (TPS), including potato starch, corn starch, and soluble potato starch, with two different gelatinization degrees to blend with poly(hydroxy butyrate) (PHB) are thoroughly discussed in this study. For blends containing a certain amount of PHB, thermal stability remains in a certain degree. In all cases of this study, mechanical properties of TPS blended with PHB confer higher performance than those of pristine TPS. In particular, a significant increase on tensile strength and tear strength is observed for TPS (potato starch) blended with PHB at low gelatinization degree. A suitable degree of gelatinization of starch is critical to achieve optimum performance. The investigation on the morphological observation partly features the supporting evidence of the above findings. The assessment of biodegradability indicates that the values of water absorption and weight loss increase with increasing treatment period and glycerol content, but decrease with increasing amount of PHB content. Among three types of starches investigated, the TPS (soluble starch)/PHB blend gives the highest level of water absorption and weight loss. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2371–2379, 2006     

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 °）。     

The Preparation of Glycerol Pseudo-Thermoplastic Starch (GTPS) via Gelatinization and Plasticization

To convert starch into glycerol pseudo-thermoplastic starch (GTPS), this research used gelatinization to destroy the crystallinity of starch granules, and then adopted glycerol plasticization to reduce the melting temperature. According to viscosity testing and X-ray diffraction (XRD), starch granules must be completely gelatinized in heated water above 80°C. The gelatinized starch was then plasticized by glycerol. Differential Scanning Calorimetry (DSC) and hot press testing indicate that starch could be effectively plasticized by gelatinization and glycerol plasticization. It is applicable to process GTPS-30 at 170°C by melting. Therefore, the method presented here should be useful in preparing GTPS.     

Structural changes of injection molded starch during heat treatment in water atmosphere: Simultaneous wide and small‐angle X‐ray scattering study

Native starches with wide varying amylose content were processed by injection molding. The injection‐molded materials were conditioned in water for 20 days and sealed in glass capillaries. Simultaneous wide‐ and small‐angle X‐ray scattering (WAXS and SAXS, respectively) were recorded during thermal heating using a synchrotron source. Crystallinity, SAXS invariant, Q, and long period, L, were measured as a function of heating temperature. The injection‐molding process provokes a destruction of the crystal forms A (cereal starch) and B (tubercle starch) but favors a development of the crystal form V_h. After wet conditioning, WAXS of the injection‐molded samples shows again the appearance of the crystal forms A or B, and crystallinity reaches values similar or larger than those of native starch. A constant heating rate (5°C/min) was particularly used for a comparison of potato and corn starch with a similar amylose content. While the crystallinity associated to forms A and B slowly decreases below 55°C and then rapidly decreases until its disappearance at 85–90°C, the invariant shows a maximum around 40°C and rapidly decreases thereafter. The total nanostructure disappearance occurs at temperatures about 10°C higher for the case of potato starch. In addition, a recovery of the WAXS and SAXS maxima during the subsequent cooling process before reaching room temperature was observed only for potato starch. Analysis of WAXS and SAXS for the rest of the starch materials reveals clear differences in the structural parameters of the samples that cannot be easily explained solely on the basis of the amylose content. Thus, for Cerestar and Roquette, it is noteworthy that there was a continuous decrease of L until its total disappearance as well as the persistence of crystallinity (form B), presumably stabilized by the presence of the V_h structure (12–15%). Real‐time crystallization experiments on two amorphous injection molded samples, waxy maize (free amylose starch) and potato starch, are also discussed. It is shown that the absence of amylose delays the recrystallization of amylopectine during the experiment. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 301–309, 2004     

不同淀粉的酸解历程及性质研究

将玉米淀粉和马铃薯淀粉分别在35℃条件下用浓度为2 4mol/L的HCl处理不同时间,采用碘量法、X射线衍射(X ray)分析和差热分析(DTA)等对酸解后的淀粉颗粒进行了结构和性能表征。结果表明,马铃薯淀粉的酸解过程可分为3个阶段,酸解速率常数分别为2 78(t<24h),0 94(24h96h)。在比较分析了玉米和马铃薯淀粉酸解前后的一些物理化学性质及结构变化与酸解时间的相互联系后,认为酸首先水解淀粉的无定型区,提高淀粉颗粒结晶度、热稳定性和酶解速率;而后随着酸解时间的延长,淀粉结晶结构遭到侵蚀,热稳定性降低。酸解时间为4d时,玉米淀粉和马铃薯淀粉颗粒的结晶最完美,热稳定性最佳,结晶转变温度分别为87 0℃和93 5℃。     

药片崩解剂羧甲基淀粉的合成

以马铃薯淀粉为原料,采用交联、醚化复合变性方法合成羧甲基淀粉,产品在常温下能快速吸水膨胀而不糊化,适用于药片崩解剂。最佳投料量：淀粉３０ｇ,氯乙酸５．０ｇ,氢氧化钠４．５ｇ,环氧氯丙烷４．８ｍｌ。     

Fermentative production of L(+)‐lactic acid from starch hydrolyzate and corn steep liquor as inexpensive nutrients by batch culture of Enterococcus faecalis RKY1

BACKGROUND: Attempts were made to determine the lactic acid production efficiency of novel isolate, Enterococcus faecalis RKY1 using four different starches (corn, tapioca, potato, and wheat starch) with different concentrations (50, 75, 100, and 125 g L^?1) and corn steep liquor as an inexpensive nitrogen source. RESULTS: The yield of lactic acid from each starch was higher than 95% based on initial starch concentrations. High lactic acid concentration (129.9 g L^?1) and yield (1.04 g‐lactic acid g^?1‐starch) were achieved faster (84 h) from 125 g L^?1 of corn starch. Among the starches used, tapioca starch fermentation usually completed in a shorter incubation period. The final dry cell weight was highest (7.0 g L^?1) for the medium containing 75 g L^?1 of corn starch, which resulted in maximum volumetric productivity of lactic acid (3.6 g L^?1 h^?1). The addition of 30 g L^?1 corn steep liquor supplemented with a minimal amount of yeast extract supported both cell growth and lactic acid fermentation. CONCLUSION: Enterococcus faecalis RKY1 was found to be capable of growing well on inexpensive nutrients and producing maximum lactic acid from starches and corn steep liquor as lower‐cost raw materials than conventionally‐used refined sugars such as glucose, and yeast extract as an organic nitrogen source in laboratory‐scale studies. These fermentation characteristics are prerequisites for the industrial scale production of lactic acid. Copyright © 2008 Society of Chemical Industry     

Effect of minor addition of xanthan on cross‐linking of rice starches by dry heating with phosphate salts

Effects of xanthan on the crosslinking of normal and waxy rice starches using a mixture of phosphate salts (sodium trimetaphosphate and sodium tripolyphosphate, 99 : 1, dry solid basis) were investigated. The starch (158.4 g, dry solids) was dispersed in an aqueous solution containing xanthan and phosphate salts (1.6 and 0.6 g in 280 mL water, respectively), and the slurry was dried overnight at 45°C until the moisture content was less than 10%. The dry cake was then ground into powders and heated for 2 h at 130°C in a convection oven. The pasting viscosity, paste clarity, melting and in vitro digestion behaviors of the starches with modifying agents (xanthan and phosphate salts) were investigated. The heat treated starches displayed enhanced shear stability and reduced breakdown, as evidences of crosslinking. Xanthan (1.0% based on starch solids) enhanced the crosslinking effects in the viscosity profile. Waxy rice starch evidenced more profound viscosity changes than did normal rice starch, indicating it was more susceptible to the heat treatment. The waxy rice starch heated with the mixture of phosphate salts and xanthan exhibited a continuous increase in pasting viscosity without any breakdown. Under a DSC analysis, melting enthalpy decreased but melting temperature increased somewhat as results of the heat treatment with xanthan. In an in vitro digestion analysis, the starches treated with xanthan exhibited decreases in the maximum digestion level, and increases in the resistant starch (RS) content. Dry heating, however, increased the digestion rate and glycemic index (GI) regardless of the presence of phosphate salts or xanthan indicating that the starches were thermally degraded. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Biodegradation of low‐density polyethylene‐banana starch films

Films were prepared by extrusion using acetylated and oxidized banana starches at different concentrations mixed with low‐density polyethylene, and their biodegradation (buried in soil) at different storage times was studied. Morphological, thermal, and mechanical characteristics of the films after degradation were tested. Films made of acetylated banana starch degraded most rapidly and those prepared with oxidized starch had the slowest degradation time. The type of chemically modified starch plays an important role in degradation of film. Burying the films produced a decrease in degradation temperature at the longest storage time, and there was a longer interval in the films prepared with native banana starch, followed by those made of acetylated starch. The buried in soil films had a broad phase transition and, consequently, an increase in enthalpy. This is due to degradation of amorphous starch zones with an increase in the crystallinity. Electron scanning microscopy analysis revealed greater degradation at longer storage time and a more marked effect in the films made of modified banana starch. Mechanical properties of the films were affected by degradation, and these varied depending on the modified banana starch used. The use of biodegradable polymers such as chemically modified banana starch might be feasible for making films with a high rate of degradation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Effect of graft-copolymerization with poly(acrylamide) on rheological and thermal properties of cassava starch

Graft copolymers of different grafting levels were synthesised by the free radical initiated reaction of cassava starch with acrylamide in presence of ceric ammonium nitrate. The viscosity properties of the native granular starch and the grafted starches were determined using a Rapid visco analyzer (RVA) and rheological properties by frequency sweep test under different conditions using a rheometer. Some of the grafted starches exhibited significantly higher and some others exhibited drastically reduced peak viscosity values irrespective of the percentage grafting. All the grafted starches exhibited very good viscosity stability as evidenced from the highly reduced breakdown and higher final viscosity values in comparison to native cassava starch. Thermal analysis of the pure granular cassava starch and grafted starches was carried out using a differential scanning calorimetry (DSC) and thermogravimetry. DSC studies showed that in comparison to native starch, the grafted starches showed lower temperatures of transition. The thermal stability of cassava starch was enhanced by grafting as observed from the thermogravimetric data. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

13C‐NMR study of Dipteryx Alata Vogel starch

Natural starches obtained by fruit seeds have been a subject of studies because of their applications, as a consequence of their chemical properties. As it is known, the fruits depend on the geographic region. Because of this, several factors affect the seed starches nature, such as granules size, morphology, components, and composition. Thus, to better understand starch properties, it is necessary to investigate the chemical behavior of these factors. This work focused on the chemical components and molecular dynamic behavior of the Dipterxy Alata Vogel (cumbaru) starch, because this fruit is very popular and is used in abundance for people because they think that it is good for some kinds of diseases. The main chemical components and the molecular dynamics of starch from the Dipterxy Alata Vogel were studied by applying solid‐state ¹³C nuclear magnetic resonance spectroscopy (NMR). © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2151–2154, 2004     

Influence of the glycerol content and temperature on the rheology of native and acetylated starches during and after gelatinization

Native potato starch was acetylated and characterized. The influence of this chemical modification on different properties of the starch was studied. The characterization included the molecular weight, thermal properties, crystallinity, amylose content, swelling behavior, and pasting and rheological properties. The chemical modification induced small changes in the crystallinity of the starch and a reduction in the gelatinization heat and in the range of temperatures at which it took place. The amylose content was determined for acetylated and native potato starches. The swelling of native granules was higher than the swelling of acetylated potato starch. Regarding pasting behavior, the native and acetylated starches responded in similar ways to changes in the temperature and glycerol content. Finally, the acetylated starch was less pseudoplastic than the native starch. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Effects of drying process for amorphous waxy maize starch on theophylline release from starch‐based tablets

Physical properties and theophylline‐release profiles of compressed tablets prepared with amorphous waxy maize starches dried using different methods were examined. A gelatinized waxy maize starch paste (10% solids in water) was either freeze‐dried or oven‐dried (40 or 105°C) until the moisture content reached to <5%. To form the tablets, the dried amorphous starch powders, either with or without theophylline (3 : 10, w/w), were remoistened to a water content of (17 ± 0.2)%, and compressed into tablets. The drying process applied to the amorphous starch powders affected both the compactness and swelling behavior of the tablets. Although no crystallinity was detected in all the starches tested, X‐ray diffraction patterns indicated that starch chains dried at the lower temperature (40°C) are allowed more time to re‐associate during the drying process than those dried at the higher temperature (105°C). The freeze‐dried starch powders formed tablets characterized by greater compactness and rigidity than was observed in the oven‐dried starch samples. The drug release of the tablets prepared with the starch dried at the higher temperature (105°C) occurred at a much slower rate than that of the tablets made with the starch dried at the lower temperature (40°C). The drug release characteristics of the freeze‐dried starch tablets were nearly identical to those of the tablets prepared with the starch dried at 105°C. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Substitution of corn starch with polycaprolactone via chlorination and water resistance of the substituted starch

Corn starch was chlorinated using methanesulfonyl chloride in dimethylformamide (DMF) and then substituted with polycaprolactone (PCL) in various solvents [dimethylsulfoxide (DMSO), water and dimethylacetamide (DMAc)] containing a catalyst [sodium hydroxide (NaOH) or lithium chloride (LiCl)] to improve water resistance. The reaction yield based on the product weight was highest (85%) when DMAc and LiCl were used. Fourier transform infrared (FTIR) spectra showed that starch was monosubstituted with PCL in the aqueous NaOH solution, whereas it was to crosslink by PCL in the case using DMAc and LlCl. The intrinsic viscosity of the products in DMSO supports these trends. By introducing the hydrophobic PCL onto starch, solvent resistance of the substituted starches to water and other aqueous media increased. The crosslinked starch displayed higher water resistance than the monosubstituted starch. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2197–2202, 2001     

高取代度玉米淀粉醋酸酯的合成与表征

以玉米淀粉为原料,醋酸酐为酯化剂,甲烷磺酸为催化剂,制备高取代度淀粉醋酸酯。研究了反应条件对产品取代度和结构的影响。结果表明:在n(淀粉葡萄糖基)∶n(醋酸酐)=1∶5.18,甲烷磺酸0.003 5 mol,反应温度75℃的条件下反应3 h,合成了取代度2.83的淀粉醋酸酯。用FTIR和1HNMR方法研究了淀粉醋酸酯的化学结构。FTIR分析表明,随着取代度的增加淀粉醋酸酯的特征峰逐渐增强;根据1HNMR谱峰的变化计算了淀粉醋酸酯的取代度,与化学滴定法测定的取代度一致;通过X射线衍射、偏光显微镜分析表明,酯化反应过程中破坏了原淀粉的结晶结构,生成了具有非晶态结构的淀粉醋酸酯。该淀粉酯已经过扩大生产,性能良好。     

Poly(lactic acid)/starch composites: Effect of microstructure and morphology of starch granules on performance

Starches used to develop biodegradable composites belong to different botanical sources that exhibit different microstructures and morphologies. This results in confused relationship and no comparison of data for applications. In this work, the most popular ten different starches were used as model materials to investigate the relationship between starch microstructure and the performance of poly(lactic acid) (PLA)/starch composites. It was found that: (a) composites filled with either well‐sized (small‐sized and non‐agglomerated) starch granules or those containing high amylose content (G‐50 and G‐80) improves the reinforcing ability of PLA, with least reduction in deformation; (b) aggregation tendency of small‐sized starch granules can be controlled using surface modification approach that not only reduces the phase‐separation between starch and PLA but also improves the dispersion; and (c) no discernible relationship exists between the starches, from different botanical sources, and the thermal performance of PLA/starch composites. The results provide practical guidelines to develop starch‐based biodegradable composites for commercial applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45504.     

Structure and properties of compression-molded thermoplastic starch materials from normal and high-amylose maize starches

The structural and mechanical properties of compression-molded normal and high-amylose maize starches were studied as a function of processing water content and ageing time. Rubbery thermoplastic starches were produced by compression molding of four maize starches with differences in amylose content and amylopectin structure. Glycerol (30% on the basis of dry starch) and water (between 10 and 35% on the basis of total mass) were used as plasticizers. After processing, the amorphous thermoplastic starch materials crystallized during ageing. The semicrystalline materials contained both E-type and V-type, as well as B-type crystallinity. The properties of the thermoplastic starch materials are dependent on water content during processing, starch source, and ageing time. The normal maize starch materials are highly flexible with elongations between 56 and 104%. The elongations of the high-amylose maize starch materials were between 5–35%. The tensile stress and E-modulus of the normal maize starch materials were in the range of 3.9–6.7 and 27–131 MPa, respectively. The tensile stress and E-modulus of the high-amylose maize starch materials increased from approximately 0.5 to 23 and 5 to 700 MPa, respectively, with increasing water content during processing from 10 to 35%. The differences in mechanical properties of the normal and high-amylose materials were explained by differences in the structure of the amylose and amylopectin structure. It was concluded that both lead to differences in the starch network. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 631–644, 1997     

Characterization of cationic starch: An efficient flocculating agent

Starch is a known carbohydrate in which, regardless of its origin, two polysaccharides are found namely amylose and amylopectin. By insertion of a cationic moiety to the backbone of starch, a modified cationic starch can be developed which can be used as flocculant. Various grades of cationic starches were developed to optimize the best performing flocculant. The base polysaccharide, starch and the best performing cationic starch i.e., Cat St3 (which have been confirmed from flocculation characteristics and intrinsic viscosity measurement) have been characterized by various characterization techniques such as determination of molecular weight, elemental analysis, FTIR spectroscopy, intrinsic viscosity measurement, thermal analysis, etc. From the characterization, it could be concluded that there was a substantial incorporation of cationic moiety onto the backbone of starch. The flocculation efficacy of these cationized starches was compared with each other and with some of the commercial flocculants available in national and international market in manganese ore suspensions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

甘薯变性淀粉的研制

总结了制取甘薯氧化淀粉、可溶性淀粉、酸变性淀粉和磷酸淀粉等变性淀粉的最佳工艺参数，并对这些变性淀粉的理化特性进行了研究。这些产品在食品、纺织、造纸、建筑、医药等行业具有广阔的应用前景。