降解淀粉与乙烯基单体AA-AN-AM接枝共聚物复鞣剂的合成及应用研究

氧化降解的玉米淀粉与丙烯酸(AA)、丙烯腈(AN)和丙烯酰胺(AM)在引发剂(NH4)2S2O8作用下进行了接枝共聚合反应,制得改性淀粉复鞣剂.研究了单体浓度及配比、引发剂浓度等因素对接枝共聚合反应的接枝率、单体转化率、接枝效率等的影响,用红外光谱对接枝共聚物的结构进行了分析表征,同时进行了应用实验.     

降解淀粉/AA-AN接枝共聚物复鞣剂的合成及应用

氧化降解的玉米淀粉与丙烯酸 (AA)和丙烯腈 (AN) ,在Fe2 + -(NH4) 2 S2 O8氧化还原引发剂作用下 ,进行了接枝共聚合反应 ,制得改性淀粉复鞣剂。研究了单体浓度及配比等因素对接枝共聚合反应的接枝率、单体转化率、接枝效率等的影响 ,用红外光谱对接枝共聚物的结构进行了分析表征 ,同时进行了应用试验     

降解淀粉与乙烯基单体AA-AN-AM接枝共聚物复鞣剂的合成及应用研究

氧化降解的玉米淀粉与丙烯酸(AA)、丙烯腈(AN)和丙烯酰胺(AM)在引发剂(NH4)2S2O8作用下进行了接枝共聚合反应，制得改性淀粉复鞣剂。研究了单体浓度及配比、引发剂浓度等因素对接枝共聚合反应的接枝率、单体转化率、接枝效率等的影响，用红外光谱对接枝共聚物的结构进行了分析表征，同时进行了应用实验。     

氧化降解淀粉与乙烯基单体接枝共聚物复鞣剂的合成及应用研究

经过氧化降解的玉米淀粉与乙烯基单体丙烯酸（AA)和丙烯腈（AN）在Fe^2 -(NH4)2S2O8氧化还原引发剂作用下进行了接枝共聚合反应，制得了改性淀粉复鞣剂。研究了单体浓度及配比、引发剂浓度等因素对接枝共聚合反应的接枝率、单体转化率、接枝效率等的影响，用红外光谱对接枝共聚物的结构进行了分析表征，同时进行了复鞣剂应用实验。     

玉米淀粉接枝丙烯酰胺合成

以Ce4 +为引发剂 ,研究了玉米淀粉 丙烯酰胺接枝共聚物形成的条件 .结果表明 ,引发剂用量、单体用量、反应温度及反应时间对合成产物的接枝率和单体聚合率有很大的影响 ,当淀粉用量为 5 .0 g ,引发剂用量为 1.0mL ,温度为 6 0℃ ,单体用量为 8.0 g时 ,单体聚合率最大 .另外 ,还研究了淀粉用量 ,Ce4 +-S2 O2 +8复合引发剂对玉米淀粉与丙烯酰胺接枝共聚的影响     

不同引发体系对苯丙接枝淀粉的影响

研究了H2O2-Fe^2＋、H2O2-CS2、（NH4）2S2O8-Na2HSO3及Ce^4＋四种不同引发体系对苯乙烯一丙烯酸丁酯接枝淀粉各项性能的影响,并用红外、扫描电镜等方法对接枝共聚产物进行了表征。通过对不同引发体系引发机理的分析和表面施胶性能测试结果的比较表明：采用H2O2-CS2做引发体系时,接枝产物的接枝率最高可达108．8％;采用H2O2-Fe^2＋做引发体系时,接枝产物的接枝效率最高可达92．4％;采用（NH4）2S2O8-Na2HSO3做引发体系时,接枝产物的单体转化率最高可达99．6％,且接枝产物的表面施胶性能在四者中最好,与原纸相比,横向环压指数提高57%纵向环压指数提高55．8%,Cobb值可降至22．2g／m^2。     

芦苇乙醇木质素与丙烯酰胺接枝共聚的研究

以(NH4)2S2O8和NaHSO3作为引发剂,研究了芦苇乙醇木质与丙烯酰胺的接枝共聚反应中丙烯酰胺用量、引发剂用量、引发剂配比、反应温度、反应时间等因素对产率和接枝效率的影响规律,并对实验条件进行优化.确定最优条件为丙烯酰胺单体与乙醇木质素的质量比为11,引发剂用量为50mmol/L,引发剂(NH4)2S2O8与NaHSO3的摩尔比为41,反应温度80℃,反应时间4h.最优条件下产物产率达到95%,接枝效率为90%.红外光谱分析证实了产物中存在接枝共聚物,并且主要以醚键连接.     

乳液接枝共聚法改性淀粉的制备及表征

以氧化降解淀粉为骨架,丙烯酸(AA)、丙烯腈(AN)、甲基丙烯酸甲酯(MMA)和丙烯酸丁酯(BA)为接枝共聚单体,过硫酸铵与亚硫酸氢钠组成的氧化-还原体系为引发剂,十二烷基硫酸钠(SDS)、Span80和亚硫酸化鱼油为乳化剂,采用乳液接枝共聚法制备可用于皮革复鞣的改性淀粉产品。以单体配比、引发剂用量、反应温度和反应时间为考察因素,产品稳定性、接枝率、接枝效率、单体转化率和在复鞣中应用的效果等为综合考察指标,经正交试验优化出的较佳合成条件为:单体配比(AA/1 0 g;AN/5 g;MMA/1 5 g;BA/1 0 g) ;引发剂用量3 0g;反应温度45℃;反应时间2 5h。此时接枝率、接枝效率、单体转化率分别为:1 5 6 8% ;82 6% ;95 %。用FT -IR、DSC、XRD和SEM对产物进行了表征,结果表明:乙烯基类聚合物已成功地接枝于降解淀粉骨架上     

氧化降解淀粉-乙烯基类单体接枝共聚反应的研究

以十二烷基硫酸钠、Span80为乳化剂 ,过硫酸铵 /亚硫酸氢钠氧化 -还原体系为引发剂 ,用乙烯基类单体与氧化降解淀粉接枝共聚 ,制备可用于皮革复鞣的改性淀粉产品。采用逐步寻优法研究了单体配比、乳化剂用量、引发剂用量 ,对接枝率、接枝效率和单体转化率的影响 ,得到较佳的合成条件为单体配比 :丙烯酸 (AA)1 0 g、丙烯腈 (AN) 5 g、甲基丙烯酸甲酯 (MMA) 1 5 g、丙烯酸丁酯 (BA) 1 0 g;乳化剂用量 :十二烷基硫酸钠 0 .75g,Span80为 5 g;引发剂用量 2 .5 g。对接枝共聚产物进行FT -IR、XRD和SEM表征。     

丙烯酸接枝淀粉的制备及其印花性能

采用丙烯酸(AA)单体对酸解玉米淀粉进行接枝,讨论了丙烯酸单体与玉米淀粉剩基（AGU）配比、丙烯酸单体pH值、引发剂用量、反应时间及温度对接枝产物接枝率、抱水性及PVID值的影响,并用红外光谱（FTIR）对接枝产物进行表征。试验得出丙烯接枝酸解玉米淀粉优化工艺为：n(AA):n(AGU)=2:1,丙烯酸单体pH值为6、引发剂n(H2O2)/n(FeSO4)=1.98,n(H2O2)=0.529mmol,接枝反应温度为50℃及时间为3h。所得接枝产物接枝率为5.14%,羧基含量为4.02%;接枝产物的抱水性为10.5mm,PVID值为0.34,各项性能与海藻酸钠相近,可作印花原糊用。     

淀粉预处理方法对多孔淀粉的影响

多孔淀粉的制备原料有玉米淀粉、木薯淀粉、马铃薯淀粉等。在制备过程中,淀粉原料某些性质的变化对多孔淀粉性质有一定影响,不同原料、或同一原料的不同处理方式都会影响多孔淀粉的形成。有效的预处理方法对改变淀粉原料的性质,提高多孔淀粉的生产效率,降低生产成本,改善多孔淀粉的性质十分重要。     

Biosynthesis of starch; identification of potato starch enzymes

Two important starch enzymes, granule-bound starch synthase and branching enzyme, were purified from potato tubers and characterized by immunological comparison with the corresponding enzymes of other plants. Granule-bound starch synthase was identified as a 60-kd protein homologous to the corresponding enzymes of maize and amaranth; the enzyme was missing in amylose-free potato starch granules. Branching enzyme of potato tubers was purified as a single protein species of 79 kd which appeared to be homologous to maize branching enzyme I, but much less to branching enzymes IIa and IIb.     

淀粉类吸附剂--多孔淀粉与环糊精的比较

从制备方法、成孔机理、吸附作用和吸附机理等方面对多孔淀粉与环糊精之间的差异进行了比较,并论述了两者在实际运用中的异同,显示出多孔淀粉良好的应用前景。     

Effect of damaged starch on wheat starch thermal behavior

The influence of damaged starch (DS) on gelatinization and retrogradation wheat starch properties was investigated. Samples with different content of DS were obtained and evaluated. DSC was used for monitoring the changes in thermal behavior of the starch samples at different water amounts. Starch thermal transitions were affected simultaneously by DS content and water content. The Flory–Huggins parameters were modified by DS. A significant raise in the T°_m, and x_1–2, and a decrease in ΔH_u was recorded. The AP retrogradation kinetics was evaluated by Avrami model. A significant increase of the AP crystallization rate was observed when DS increased. The results demonstrated the importance of the presence of physically damaged granules on wheat starch properties.     

直链淀粉含量对抗性淀粉形成的影响

考察不同直链淀粉含量的高直链玉米淀粉形成抗性淀粉的能力。结果表明:随着直链淀粉含量的增加抗性淀粉含量增大,最高可达20.74%,普通玉米淀粉的抗性淀粉得率仅为9.09%。     

零余子淀粉及其淀粉糊特性研究

对零余子淀粉的颗粒形态、晶体结构、淀粉糊性质进行了研究,并与山药淀粉选行比较.结果表明,零余子淀粉颗粒呈卵圆形,支链淀粉含量大于直链淀粉,X-射线衍射表明,零余子与山药淀粉均为C型晶体结构,结晶度分别为32.02％和34.32％.DTG曲线分析表明,零余子、山药淀粉的最大失重速率温度分别为311.3℃和313.8℃.零余子和山药淀粉糊液为非牛顿流体,剪切使糊液变稀,淀粉糊的动态流变行为表现为低剪切速率对两种淀粉糊凝胶特性影响不大,当剪切速率大于80r·s-1时,升温会导致淀粉糊由凝胶向溶胶转变.     

芋头淀粉提取工艺优化及淀粉特性研究

以NaOH为浸泡剂,探讨了料液比、pH、浸泡时间、浸泡温度对芋头淀粉提取率及色泽的影响,并对芋头淀粉特性进行了初步研究。结果显示芋头淀粉提取最佳工艺条件为：pH10.0、浸泡温度25℃、料液比1：3、浸泡时间80min。提取率可达84.82%,淀粉白度高达94.11,优于现有文献报道及市售其它常用淀粉;淀粉特性研究显示,芋头淀粉的体积平均粒度在10μm以下,d（0.5）为14.6μm,稍大于10μm;芋头淀粉具有优良的热稳定性、冷稳定性,凝胶强度和凝成特性等特性。     

Gelatinisation of starch and wheat flour starch—A review

Gelatinisation of wheat starch is reviewed, making comparisons with other starches.Starch in wheat kernel endosperm is briefly described. Various aspects of gelatinisation of starch in water are considered, including swelling and interaction with water before the onset of gelatinisation, increase in consistency during gelatinisation, gelatinisation temperature, types of gelatinised system and gel and paste formation upon cooling. In addition, the traditional rationale of gelatinisation and gelatinisation from the viewpoint of water mobility are discussed.Experimental methods used to study gelatinisation are also reviewed, as are the effects of starch concentration, protein, pentosans, surface active agents, fats, salt and sugars on gelatinisation and shear rate on consistency.     

Utilization of rice starch with gums in Asian starch noodle preparation as substitute for sweet potato starch

Starch noodles were produced using a medium grain rice starch in the presence of various gums, and physical properties of the noodles were compared with sweet potato starch noodle. Pasting viscosity of the rice starch was lower than that of sweet potato starch (830 vs. 1,618 cp as peak viscosity). The peak viscosity, however, was increased by the addition of gums (0.1% based on dispersion), and especially xanthan was the most effective in increasing the peak viscosity (1,478 cp). The cooking loss for the rice starch noodles (1.5 mg/mL), greater than that for the sweet potato starch noodle (0.2 mg/mL), was effectively reduced to 0.8 and 0.9 mg/mL, respectively, by the addition of locust bean gum (LBG) and curdlan. The addition of LBG or gellen gum also increased the hardness of the rice noodles. Aging (extended retrogradation) the noodles was effective in reducing the cooking loss and improving the textural properties of the rice starch noodles. The combination of the gum addition (like LBG) and aging of the rice starch noodle might be useful for utilizing rice starch as a substitute for sweet potato starch in Asian noodle preparation.