磷酸酯淀粉合成反应动力学研究

本文研究了淀粉磷酸酯化的反应动力学过程,讨论了复合磷酸盐配比、复合磷酸盐用量等反应条件对取代度的影响,不同反应温度对淀粉磷酸酯化反应速率的影响。结果表明,提高反应温度,反应速率明显加快,淀粉磷酸酯化反应符合二级动力学的反应机理,磷酸酯化反应的表观活化能Ea=14.6 kJ·mol-1。     

利用机械活化木薯淀粉制备淀粉磷酸酯的工艺研究

由于淀粉是一种多晶高聚物,其颗粒中一部分分子排列成疏松的非晶区,另一部分分子则排列成高度有序的结晶区,磷酸盐不易深入到颗粒内部,反应往往只能发生在颗粒表面,导致淀粉反应活性和反应效率较低,难以得到高取代度的产物.今利用自制的搅拌球磨机将普通木薯淀粉进行机械活化预处理,正磷酸盐为酯化剂,尿素为催化剂,干法制备淀粉磷酸酯.探讨了活化时间、磷酸盐用量、pH值、反应温度、反应时间和尿素用量对取代度(DS)和反应效率(RE)的影响,确定了最佳反应条件:活化时间1.5 h,磷酸盐用量12%,pH4.5,反应温度150℃,反应时间2 h,尿素用量2%.研究结果表明:机械活化预处理方法能显著提高木薯淀粉磷酸酯的DS和RE,表明机械活化能有效地提高木薯淀粉的化学反应活性.最佳工艺条件下木薯淀粉磷酸酯的DS和RE为0.0900和0.933.     

碎米淀粉磷酸酯化的研究

在制取取代度为0.01～0.02的碎米淀粉磷酸酯化的实验中,考察了pH值、反应温度、反应时间、尿素用量和磷酸盐用量对酯化反应的影响,结果表明,磷酸盐用量(与淀粉的干重比)为0.0402,pH值为5.1,反应温度为150 ℃,反应时间105 min时,酯化淀粉的粘度值为3 850 mPa·s.     

淀粉磷酸酯的制备及其应用研究

以淀粉和磷酸盐为原料.在搅拌和N2保护下恒温反应,制得了取代度较高的淀粉磷酸酯.并考察了反应的pH值、反应温度和时间、磷酸盐的用量及种类对最终收率和取代度的影响,适宜的反应条件为NaH2PO40.019～0.050、60～80 C、1～2h、pH值与磷酸盐种类有关。     

纺织浆纱用复合变性磷酸酯淀粉的制备研究

实验通过将淀粉经交联、酸解后磷酸酯化反应的复合变性研究，并进行有关性能的测定，寻找出一条最佳的反应条件，使复合变性磷酸酯淀粉的使用性能符合纺织浆纱工艺的要求。实验中发现，在一定的交联度下，用尿素为催化剂，其最佳的反应条件为：浓盐酸用量为6%，Na2HPO4用量为28.7%，NaH2PO4用量为15.5%，T酯化为127℃，t酯化为3h。     

赤铁矿反浮选抑制剂变性淀粉的制备及应用性能

本文采用干法工艺,以木薯淀粉为原料,在固相中与酯化剂磷酸二氢钠、氧化剂过氧化氢进行反应,制备复合变性淀粉。讨论了酯化剂、氧化剂、催化剂、反应温度、反应时间、反应体系水的质量分数、反应pH值等因素对反应的影响。实验结果表明,当酯化剂NaH_2PO_4用量为淀粉质量的4.0%,氧化剂过氧化氢用量为淀粉质量的1.0%,催化剂用量为淀粉质量的2.0%,反应pH值为6.0,体系水分含量为25%时,低温60℃反应3h,高温135℃反应2h,制备所得产品的指标为:酯化取代度DS为0.0545,羧基含量为0.0862%,在赤铁矿反浮选中作为抑制剂,效果显著。     

聚乳酸/淀粉复合发泡材料的研究(Ⅰ):发泡工艺的研究

挤出制备聚乳酸/淀粉复合发泡材料,研究淀粉、AC发泡荆、马来酸酐、BPO含量以及螺杆转速对发泡材料性能的影响.结果发现,淀粉含量不宜超过20%,过多会使体系发泡性能趋于不稳定,AC发泡剂用量应在3%～4%左右,马来酸酐及引发剂BPO的加入有利于改善复合体系的相容性,从而提高发泡性能,螺杆转速应维持在100rpm～200rpm.     

碱性过硫酸钾氧化-紫外分光光度法测定淀粉磷酸酯中氮含量

采用碱性过硫酸钾氧化-紫外分光光度法测定淀粉磷酸酯的氮含量,研究了消化时间、反应温度、冷却放置时间等条件对吸光度的影响,确定了最佳实验条件,建立了一种简便易行的测定氮含量的方法.在选定条件下,对淀粉磷酸酯样品进行分析, 结果理想,精密度较高,相对平均偏差为0.50%～1.3%,加标回收率为90%～99%.     

糖的磷酰化反应研究

选用磷酸氢二钠和磷酸二氢钠的混合盐作酯化试剂与葡萄糖反应,制备了葡萄糖磷酸酯,考察了酯化剂用量、磷酸盐混合物的质量比、催化剂尿素等因素对葡萄糖磷酸酯的取代度和反应效率的影响。结果表明,制备葡萄糖磷酸酯的最佳反应条件为:反应温度80℃,磷酸盐和葡萄糖的质量比为1∶1,磷酸二氢钠与磷酸氢二钠的质量比为3∶1;催化剂加入量为葡萄糖含量的10%,反应时间为6 h。用水作溶剂,合成了水溶性较好的Ca、Cu、Zn等金属磷酸酯配合物,并进行了红外光谱分析。另外,对多糖——纤维素进行磷酰化,测定了其产物的络合能力。     

新型磷酸酯的合成及萃取性能研究

采用芳香基酚与P_2O_5酯化反应,制备新型磷酸酯萃取剂,并对其在高浓度硫酸体系下萃镓性能进行研究。实验表明,最佳合成条件为:(1)酯化反应:n(P_2O_5)/n(辛基酚)=4∶3,反应时间4 h,反应温度75℃,溶剂用量V(环己烷)(L)/n(P_2O_5)(mol)=1∶1;(2)水解反应:加入水量n(H_2O)=0.75n(P_2O_5),水解时间1.5 h。在此条件下,磷酸酯收率99%。磷酸酯萃取剂用于锌湿法冶炼渣的硫酸浸出液(H_2SO_420¹00 g/L)萃取,可选择性萃取Ga,Ga单级萃取率80%以上,2级萃取97%以上,实现Ga与Zn、Cu、Ge分离。     

Preparation,forms and properties of controlled-release phosphate fertilizers

Controlled-release phosphate fertilizers include phosphate rocks (PRs) for direct application, partially acidulated phosphate rocks (PAPRs) and thermal phosphates. Phosphate rocks contain apatite as the main P containing mineral, the composition and the chemical nature of which vary between PRs. Based on the solubility in chemical extractants PRs are broadly grouped into ‘reactive’ and ‘unreactive’. The ‘reactivity’ of PRs is influenced strongly by the extent of carbonate substitution for phosphate in the apatite minerals. Under certain soil and climatic conditions reactive PRs (RPRs) can be used as a source of P for direct application. Partially acidulated phosphate rocks (PAPRs) are produced either by direct partial acidulation of PRs with mineral acids or by mixing PRs with fully acidulated superphosphate reaction mixtures. Partial acidulation of PRs with H₃PO₄ generally results in higher water soluble P contents than those acidulated with H₂SO₄. Mixing of RPRs with superphosphate reaction mixtures sometimes results in the preferential consumption of free acid and thereby increases the amounts of residual unreacted PRs. Thermal phosphates are produced by either heating PRs below melting point both in the presence and the absence of silica (calcined phosphates) or heating PRs with silica above melting point (fused phosphate). These phosphates are alkaline in nature and hence suitable for acidic soils.     

磷化处理技术

介绍了磷化工艺的原理、作用及分类方法、常用的磷化及预处理的配方实例。     

磷酸二氢铵应用研究进展

中国磷矿资源丰富,为磷酸盐工业的发展带来了重大机遇。磷酸二氢铵作为重要的磷酸盐系列产品之一,常用作氮-磷复合肥广泛使用,但肥料利用率低,附加值不高,造成资源浪费,阻碍了磷化工的发展。重点综述了磷酸二氢铵在灭火剂、阻燃剂、玻璃材料、磷酸铁锂材料和基体改进剂等领域的应用,为拓展磷酸二氢铵的应用领域、提高磷酸二氢铵附加值提供了借鉴。最后,对磷酸二氢铵今后的研究方向进行了展望。     

全球饲料磷酸盐市场现状与发展方向

评述了世界饲料磷酸盐产品的品种，包括磷酸氢钙、磷酸二氢钙、脱氟磷酸钙等，市场需求量变化情况，主要生产工艺的比较，生产能力与产量变化及现状等。介绍了影响饲料磷酸盐市场需求变化的因素并对饲料磷酸盐所面对的生物技术、生物效价、生产环保等问题进行分析，预测了饲料磷酸盐的发展方向。     

Partially acidulated phosphate rocks: Phosphorus release characteristics

Five phosphate rocks varying in formic acid P solubility from 18.9 to 52.7%, expressed as percentage of total P, were acidulated with phosphoric or sulphuric acids to 0, 20%, 33% and 50% of full acidulation and granulated. In an incubation experiment fertilizer granules of diameter 1–2 mm were mixed with two acid soils and after 1 week incubation soil samples were extracted with a 0.5 M NaOH solution. In a dissipation experiment single fertilizer granules of 4 mm diameter were implanted into soil, incubated for 1 and 4 weeks and inorganic P fractionation in the residual granules and the surrounding soil was performed. Dissipated P was greater than the water soluble P content of the partly acidulated phosphate rock fertilizers indicating the dissolution of the non-acidulated phosphate rocks. The amount of P dissipated was related to the initial water soluble P content and to the formic acid solubility of phosphate rocks used for manufacturing the fertilizers. The P dissipated increased with an increase in soil acidity.     

对我国饲料磷酸盐生产的建议

在介绍国内外饲料磷酸盐发展概况的基础上，重点论述了饲料级磷酸氢钙和脱氟磷酸钙的生产方法和技术进步，并对加快我国饲料磷酸盐生产的发展提出了一些看法。     

Single superphosphate - reactive phosphate rock mixtures. 3. The use of concentration ratios of elements to identify the nature and amounts of unacidulated rock residues in the mixtures

Water insoluble residues (WIR) of unreactive phosphate rocks in single superphosphate-reactive phosphate rock (SSP-RPR) mixtures are considered to reduce the agronomic value of these mixtures. A technique using concentration ratios of elements to identify the quantities of WIR of ground North Carolina (NC), ground Nauru and as received NC phosphate rocks in a SSP-RPR was developed. Of 22 elements tested P/Sr ratios were found to be the only element ratios that could be used to distinguish between WIR's derived from Nauru and NC. P/Sr ratios in Nauru and NC were markedly different and provided a useful index for differentiating between the two rocks. During acidulation the P/Sr concentration ratio remained essentially constant in the WIR's from both rocks.Using the element ratio technique the percentage of total P in the SSP-RPR sample was determined to be 60-61% water soluble, 5% water insoluble Nauru, 2% water insoluble ground NC and 32-33% water insoluble as received NC.The element ratio technique developed in this study can be applied to partially acidulated P fertilizers made with rocks other than NC and Nauru provided elements which satisfy the same conditions as Sr in this study can be found.     

磷肥增效技术研究进展

分析我国磷矿资源特征、磷肥生产和农业用磷现状,提出研究磷肥增效技术来提高磷肥利用率。详细探讨了部分酸化磷肥、包膜磷肥和载体磷肥的国内外研究现状和进展,指出磷肥增效技术的研究和应用对我国农业可持续发展、节约磷矿资源和保护环境具有重要意义。     

提高磷化膜质量的除磷化渣技术研究

针对磷化渣产生的机理及危害,分析了磷化液中磷化渣的沉降特性,并在此基础上,结合本公司涂装车间,提出了一种新的除磷化渣装置系统及其管理技术。