抗消化乙酰酯淀粉结构和结肠靶向性能研究

采用扫描电镜、X射线衍射和生物体外(In-V itro)降解等方法,对不同取代度DS的抗消化乙酰酯淀粉的颗粒形貌、结晶结构和生物降解性能进行了研究。结果表明:乙酰酯淀粉的颗粒表面变得粗糙并发生破损;随着乙酰基团取代度的增大,淀粉的抗消化性能不断提高,当DS>2时,淀粉中抗消化淀粉质量分数达到90%以上,其结晶结构也由A型向V型转变。生物体外降解试验表明,抗消化乙酰酯淀粉薄膜在模拟人体上消化道环境中的降解程度低于2.5%,在人工模拟结肠环境中的微生物降解程度为30%—50%,显示出潜在的结肠靶向性和微生物降解性。由此可见,抗消化乙酰酯淀粉适合作为菌群触发型口服结肠靶向药物控释载体材料。     

三偏磷酸钠交联对羧甲基淀粉性能的影响

以木薯淀粉为原料,三偏磷酸钠为交联剂,采用溶剂法"一步法"制备了交联羧甲基淀粉,研究了三偏磷酸钠交联对淀粉的溶胀性、特性黏度、分子量及其糊液的黏度、抗酸碱性能、耐温性能、抗剪切性能的影响。结果表明,交联改性降低了淀粉的溶胀性,提高了淀粉的特性黏度和分子量;适度交联能显著提高淀粉糊液的黏度、抗酸碱性能和耐温性能,抗剪切性能也得到有效改善。红外光谱分析(FTIR)证实了木薯淀粉发生了交联反应和羧甲基化反应;X-射线衍射分析(XRD)证实了木薯淀粉经羧甲基化后结晶度降低,交联羧甲基淀粉的结晶度略高于羧甲基淀粉;扫描电镜分析(SEM)证实了交联羧甲基化反应不仅发生在淀粉颗粒表面,也发生在淀粉颗粒内部。交联羧甲基淀粉综合性能优于羧甲基淀粉,可大大拓宽产品的应用范围。     

羧甲基酵母葡聚糖在护肤品中的应用研究

以一氯乙酸钠为醚化剂羧甲基化修饰酵母β葡聚糖,通过测定红外光谱和取代度鉴定制备的羧甲基葡聚糖样品。比较改性前后酵母葡聚糖的吸湿、保湿性能,初步研究羧甲基葡聚糖的人体皮肤刺激性和改善皮肤纹理深度的作用。结果显示制得的羧甲基葡聚糖取代度为0.60,羧甲基化修饰后葡聚糖保湿吸湿能力增强,能减轻由果酸引起的皮肤红斑和刺痛感,并具有抗皱功能,是一种有效的功能性皮肤护理成分。     

环氧改性聚酰胺对淀粉基生物降解复合膜性能的影响

将环氧改性聚酰胺(EPA)与热塑性玉米淀粉复合后采用浇铸法制备出新型增强生物降解复合膜,研究了EPA对复合膜结晶性能、交联程度、力学性能以及生物降解性能的影响。结果表明,玉米淀粉与EPA、烷基烯酮二聚体及丙三醇复合后,结晶程度明显下降。当EPA质量分数为21 62%时,复合膜的交联度高达45 77%,且复合膜残留物中非EPA成分的质量分数也达到24 15%;复合膜的干态拉伸强度和断裂伸长率分别可以高于12 0MPa和45 0%,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。EPA的添加降低了复合膜的生物降解性能。     

交联氧化羧甲基化改性淀粉制备工艺研究

采用交联、氧化、羧甲基化多重淀粉改性技术,制备了具有羧甲基、交联、氧化淀粉的交联氧化羧甲基化改性淀粉。研究了乙醇、碱液(氢氧化钠溶液)、氯乙酸用量、反应温度和反应时间对取代度的影响,探讨了交联剂和双氧水用量对黏度及黏合力的影响,通过单因素实验得到了最佳工艺参数,解决了普通改性淀粉抗剪切稳定性差、不耐酸和盐、溶胀性差、透明度低等问题。     

羧甲基葡甘聚糖的制备

葡甘聚糖经羧甲基化改性后,其溶解性、抗潮性、成膜性能等明显改善,可用作空心胶囊的囊材。通过正交试验,得出了葡甘聚糖羧甲基化改性作囊材的最佳反应条件：6g魔芋精粉,6g氯乙酸,1．2g碘化钾,70℃水浴反应4h,所得产物的取代度为0.571。研究了改性后羧甲基葡甘聚糖的理化性能。     

倒卵叶五加多糖的羧甲基化工艺及抗氧化性

为了确定羧甲基化倒卵叶五加多糖的最优合成工艺,通过响应面分析法,以多糖羧甲基化的取代度为响应值,考察了反应时间、氯乙酸浓度和反应温度对多糖羧甲基化取代度的影响。结果表明:当反应时间4.1h,氯乙酸浓度3.3 mol/L,反应温度75℃,羧甲基化倒卵叶五加多糖的取代度为0.557;优化条件下得到的羧甲基化倒卵叶五加多糖的抗氧化性能有了明显改善。研究结果对进一步拓宽倒卵叶五加多糖的应用具有一定的参考价值。     

干法制备高取代度高黏度羧甲基淀粉

以马铃薯淀粉和氯乙酸钠为原料,通过分阶段碱化和醚化方法,采用先进的干法工艺制备了高取代度、高黏度的羧甲基淀粉。并详细考察了氯乙酸钠用量、碱用量、反应温度及时间等条件对产品取代度和黏度的影响。实验结果表明,当淀粉、氯乙酸钠及氢氧化钠摩尔比为1:1:1．25时,在碱化和醚化反应温度、时间分别为35℃、 60 min和70℃、2．5 h条件下,可制备出取代度最高达0．73,反应效率为73％,黏度可达11 600 mPa·s的高取代度、高黏度羧甲基淀粉。     

羧甲基壳聚糖的制备及其应用研究

研究了在水媒介中,利用微波加热使壳聚糖发生羧甲基改性反应。探讨了碱化时间、微波加热时间、投料比等工艺条件对壳聚糖羧甲基化程度及产物收率的影响,并对产物进行了红外光谱分析、取代度测定、粘度分析。确定最佳工艺条件。壳聚糖：氢氧化钠：氯乙酸=1：15：12,碱化时间=2h,微波加热时间=25min,制得羧甲基壳聚糖取代度和收率分别为0．71和83％。     

羧甲基壳聚糖-油酸胶束的制备

通过接枝反应合成了具有两亲性的羧甲基壳聚糖-油酸聚合物,并测定了临界胶束浓度(CMC),评价其形成胶束的能力。首先对壳聚糖进行羧甲基化修饰,酸碱滴定法测定取代度,并以取代度为指标,正交实验法确定合成羧甲基壳聚糖过程中不同条件对取代度的影响,根据正交实验结果制备了3种不同取代度的羧甲基壳聚糖,分别与油酸进行接枝反应,合成了3批羧甲基壳聚糖-油酸聚合物,荧光光度法分别测定CMC值为0.013 8、0.039 0和0.039 0 mg/mL,结果表明羧甲基壳聚糖-油酸具有形成胶束结构的能力。     

Optimization of Carboxymethylation of Starch in Organic Solvents

A comparative study of the influence of ethanol, benzene, acetone, isopropanol, and mixtures of ethanol-acetone, ethanol-benzene, and ethanol-isopropanol as slurry media on the degree of substitution and viscosity of carboxymethyl starch during carboxymethylation is presented. It is shown that the degree of substitution increases with increasing acetone, isopropanol, or benzene content in the mixed solvent. After the same carboxymethylation steps the degree of substitution with ethanol/benzene mixture is higher than that with ethanol/isopropanol mixture.     

两性淀粉的取代度与吸湿保湿性能关系的研究

以淀粉为母体，3-氯-2-羟丙基三甲基氯化铵和氯乙酸为改性剂，通过清洁的半干法工艺合成出不同羧甲基取代度高的水溶性两性淀粉，并对其吸湿、保湿性能进行研究。结果表明，两性淀粉的吸湿、保湿性能均随着羧甲基取代度的增加而增强。当RH为81％，阴离子取代度大于0．08时，两性淀粉的吸湿性与甘油相当，而保湿性在RH81％和RH38％下均优于甘油；两性淀粉的吸湿速率随着羧甲基阴离子含量增加而提高。初步探讨了两性淀粉的吸湿动力学，水分子在两性淀粉中的扩散属于non-Fickian类型。     

Starch derivatives of a high degree of functionalization. VI. Multistep carboxymethylation

For the first time, carboxymethyl starch (CMS) samples with a very high degree of substitution (DS_CM = 2.1) were synthesized by multistep carboxymethylation under heterogeneous reaction conditions in methanol/water with sodium hydroxide and monochloroacetic acid as an etherifying agent. The stepwise increase in the total DS_CM value gradually decreased with an increasing DS_CM value of the starting polymer. The determination of the functionalization pattern of CMS by ¹H‐NMR spectroscopy after chain degradation indicated a high preference for 2‐O‐substitution. The distribution of the carboxymethyl functions was in the order O‐2 ? O‐6 > O‐3. A detailed analysis of the depolymerized sample by means of high‐performance liquid chromatography and capillary electrophoresis revealed a monomer composition that was in very good agreement with the statistical model of Spurlin. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 743–752, 2002     

Biodegradation behavior of acid‐containing cellulose acetate film in soil

The biodegradation behavior of various cellulose acetate (CA; degree of substitution = 2.5) films that contain acids was examined by a laboratory soil burial test to clarify the effects of additives on the biodegradability of CA. The biodegradation rate of the CA films containing polyphosphoric acid, phosphoric acid, and p‐toluenesulfonic acid increased compared to that of the nonadditive CA film. CA films containing mandelic acid and maleic acid showed a small tendency to increase. Conversely, CA films containing adipic acid did not affect the biodegradability of CA. A similar experiment was carried out with a sterilization system. The acid‐containing CA film, which showed an accelerated biodegradation rate, was chemically deacetylated by contact with water in the environment and was consequently converted to a lower degree of acetyl group substitution matter that had higher biodegradability. An IR analysis suggested that this deacetylating ability of acids is correlated with the intensity of their interaction with the acetyl group of CA. In the biodegradation process, the contact efficiency of acids to CA was considerably lowered by the elution of internal acids with time. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 466–473, 2005     

一次羧甲基化制备高取代度(DS=2.20)羧甲基玉米淀粉

通过一次羧甲基化制备了DS=2.20的高取代度羧甲基玉米淀粉(CMCS)。研究了氢氧化钠用量、反应介质、反应时间和反应温度对反应效率(RE)和取代度(DS)的影响。当n(NaOH)/n(AGU)=4时,最佳反应条件为n(NaOH)/n(ClCH2COOH)=2.5、异丙醇中φ(水)=2.4%、反应温度50℃、反应时间2h,在最佳反应条件下制得CMCS的DS=2.20,RE=55%。另外,用红外光谱证明了CMCS中存在羧甲基结构。     

Synthesis,characterization, and biodegradability of fatty‐acid esters of amylose and starch

A series of starch and amylose esters with different degrees of substitution and side‐chain length were prepared and studied. The esters were prepared by acylation of the polysaccharide with the appropriate acid chlorides, such as octanoic, dodecanoic, and octadecanoic. The degrees of substitution were 0.54, 1.8, and 2.7. After preparation, the resulting esters were characterized by elemental analysis, ¹H nuclear magnetic resonance (¹H‐NMR), Fourier transform infrared (FTIR), differential scanning (DSC), thermogravimetric analysis (TGA), contact angle, and water uptake measurements. Their mechanical properties and, in particular, the tensile strength and elongation at break depend on the side‐chain length and on the degree of substitution. The extent of their biodegradability, after exposure to activated sludge, was assessed by weight loss measurements and scanning electron microscopy (SEM). It was found that these new materials are biodegradable, and the biodegradation rate decreases with increasing degree of esterification. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1440–1451, 1999     

三氯氧磷交联木薯淀粉的消化性能及酶降解程度

采用In Vitro消化模型模拟人体消化道环境 ,对不同交联度 (DC)的三氯氧磷淀粉 (DC =3.70× 10 -5至 2 .2 7×10 -2 )的消化性能进行了研究 ;同时用微生素酶对三氯氧磷交联木薯淀粉进行生物降解并测定各个样品的抗酶解淀粉 (RS)含量。三氯氧磷交联变性处理对木薯淀粉的消化速度和生物降解程度的影响随交联度的不同而不同。高交联特别是使淀粉达到完全非晶化时对淀粉的消化速度和生物降解程度影响更大。     

Preparation and characterization of carboxymethyl starch under ultrasound‐microwave synergistic interaction

Using native cassava starch as raw materials, carboxymethyl starch (CMS) was prepared by ethanol solvent method under the ultrasound‐microwave synergistic interaction. And the structure of CMS was characterized employing Fourier transform infrared (FTIR) spectrometer, scanning electron microscopy (SEM), X‐ray diffraction (XRD) and thermogravimetric analyzer. Typically, the optimal synthesis conditions for the preparation process confirmed by orthogonal experiment L₁₈ (6¹ × 3⁶) were shown as follows: the ultrasonic treatment temperature was fixed to 35°C and two steps alkalization was employed; the ultrasonic time was 40 min before alkalizing and the ultrasonic power was 220 W; the amount of sodium hydroxide was 8.8 g, the microwave alkalization time was 2 min; the amount of monochloroacetic acid was 11.34 g; the amount of 95% (v/v) ethanol was 70 mL; the microwave etherification time was 3 min. The degree of substitution of prepared CMS was 1.089 ± 0.041, which was increased 30.4% compared with the prepared sample without ultrasound‐microwave synergistic treatment. FTIR results showed that the strong ? COO? characteristic absorption peaks of the stretching vibration were observed at 1613 and 1421 cm^?1, which proved that the carboxymethylation of cassava starch was occurred. SEM results suggested that there were many cracks and dents on CMS granules; and, XRD results indicated that the carboxymethylation of starch occurred both in amorphous region and crystalline region, the noticeable damage of crystalline region by carboxymethylation was observed. Thermogravimetric analysis (TG) and derivative TG showed that thermal stability of CMS changed better compared with native starch. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40906.