悬浮聚合法制备磁性微球的粒度分布特性

本文研究了含有微细铁黑颗粒的混合单体悬浮聚合产物的粒度分布特性。分析了分散剂、超声预分散和无机铁黑颗粒对形成粒度多峰分布的影响。结果表明,分散剂是体系中形成小颗粒的主要因素;超声波的预分散作用使悬浮体系的液滴破裂以“腐蚀破碎（erosive breakage)”为主;无机铁黑颗粒由于其表面亲水性,倾向于分布在油性单体液表面,不仅有利于悬浮液滴的“磨蚀破碎”,同时也对分散液滴具有良好的稳定作用。上述因素的共同作用使得聚合产物的粒度呈三峰分布。     

悬浮法PVC的颗粒形态及改进方法

概述了悬浮法PVC的颗粒形态，并详细介绍了改进悬浮法PVC颗粒形态的方法：选择适宜的分散体系[如Mg(OH)2无机分散体系、离子敏感性分散剂、PVA复合分散剂、TiO2分散剂等]及合适的引发剂(如使用引发剂乳液、加入有机钴等)；采用倒加料法及后加分散剂的聚合进料工艺。     

羟基磷酸钙的制备及其对甲基丙烯酸甲酯悬浮聚合的影响

利用Ca(OH)2和H3PO4中和反应制备悬浮聚合分散剂超细羟基磷酸钙(HAP). 通过正交实验法,研究了反应温度、Ca(OH)2浓度、H3PO4滴加速度、表面活性剂十二烷基苯磺酸钠(SDBS)的加入量等各因素对反应产物羟基磷酸钙结晶形态与尺寸的影响. 分别将不同条件下制备的HAP与聚乙烯醇(PVA)组成复合分散体系,通过甲基丙烯酸甲酯(MMA)的悬浮聚合反应,比较了各组的聚合效果. 应用红外光谱及透射电镜对HAP进行了表征,分析了HAP的结晶形态及尺寸对聚甲基丙烯酸甲酯(PMMA)的粒径及其分布的影响. 结果表明,本实验制备的长′宽为140 nm×35 nm的针状结晶HAP与PVA的复合分散体系对MMA悬浮聚合效果最好,可制备出综合性能较好、粒径d32达1.41 mm的PMMA光学小球.     

复色多相聚合物/ 油/ 水分散体系的悬浮稳定性及分散稳定性

采用Ｓｔｏｋｅｓ落球模型研究了两相密度差对油／水分散体系悬浮稳定性的影响规律,考察了水相粘度及水相界面张力对油／水分散体系分散稳定性的影响。结果表明：复色多相分散体系的悬浮稳定性主要由两相密度差决定,当两相密度差降至０．５ｋｇ／ｍ３时,可以制得悬浮稳定性很好的复色多相分散体系。水相粘度增大,悬浮稳定性提高。水相界面张力对丙烯酸酯－聚氨酯油相形成的分散体系影响较大,当其界面张力大于６９．５×１０－３Ｎ／ｍ时,分散稳定性好。只要粒子间不易相互融结,形成的复色多相分散体系便不发生渗色现象。     

羧酸盐磺酸盐共聚物分散剂合成及其分散性能

合成了丙烯酸(AA)-苯乙烯磺酸钠(SSS)-顺丁烯二酸酐(MA)三元共聚物钠盐分散剂,研究了其对无机物BaSO4和有机物农药吡虫啉的分散效果,并对BaSO4悬浮颗粒的形貌、晶型结构及粒径分布进行了表征.结果表明,当单体质量比AA:SSS:MA=20:4.5:2.0、反应温度70℃、引发剂占单体总质量7.5%、聚合时间1.5h时,制备的最优化分散剂M17在20℃的中性体系中对BaSO4的悬浮率达98.78%,平均粒径为0.454μm,对70%吡虫啉水分散粒剂的悬浮率为84.40%,分散效果与罗地亚T36相当.     

反相悬浮聚合技术的研究进展与应用

介绍了反相悬浮聚合技术合成球状亲水性高分子材料的优势及其在球状超强吸液树脂、酶固定化载体和高分子絮凝剂等领域的应用,着重讨论了反相悬浮聚合体系中成球聚合的影响因素,指出与单体相匹配的分散剂和分散介质的选择是影响聚合体系稳定性和产物性能及制备成本的关键,具有分散和隔离保护双重作用的高分子表面活性剂的开发应用是发展趋势和研究热点。     

丙烯酰胺反相悬浮聚合分散剂的研究

研究了非离子型表面活性剂(Span系列和Tween系列)种类和用量对丙烯酰胺(AM)反相悬浮聚合体系的稳定性及平均粒径的影响,发现由S—65和S—40构成的复合分散剂,且当HLB值为4.5时,分散体系的稳定性最好,产率出现最大值,分散液滴的直径出现最小值。     

羟丙基甲基纤维素在聚氯乙烯工业中的应用

羟丙基甲基纤维素(HPMC)，是聚氯乙烯(PVC)工业的主要分散剂品种之一。氯乙烯悬浮聚合时，它可以降低VCM和水之间的界面张力，帮助氯乙烯单体(VCM)均匀而稳定地分散在水介质当中；在聚合过程初期防止VCM液滴并合；在聚合过程中后期防止聚合物颗粒之间聚并。在悬浮聚合体系中，它起着分散和保护稳定的双重作用。     

在无机分散剂存在下苯乙烯悬浮聚合宏观成粒的特征

以苯乙烯悬浮聚合为体系,考察羟基磷酸钙(HAP)或HAP与聚乙烯醇(PVA)复合为分散剂体系时,各种因素如分散剂浓度、油水比、搅拌速度等与瞬时液滴大小及分布之间的关系,并分析讨论瞬时液滴分散、合并的过程特征.结果表明,悬浮苯乙烯液滴聚合宏观成粒的特征与分散剂的分散机理无关,仅体现液滴分散、合并的过程特点.当采用分批加分散剂时,实验观察到瞬时液滴大小分布呈由单峰过渡到双峰,再发展成单峰分布的特征,从而找出了以分批加分散剂方式制备窄分布聚合物颗粒的理论依据.     

农药水悬浮剂的研究开发

水悬浮剂(Suspension Concentrate,SC)(水乳剂, Emulsion in Water,EW)是指不溶于水的固体原药(液态原药或原药溶液)通过一定机械手段(砂磨或球磨) (高速剪切乳化或高速搅拌等)分散在水中形成的多相分散体系。水悬浮剂外观为不透明悬浮体,其分散相粒径一般为0.5～5μm,平均粒径2～3μm,水悬浮剂属于热力学不稳定多相分散体系。     

子空间模型辨识方法综述

作为传统线性系统辨识方法的一个有益补充,子空间模型辨识方法（SMI）近年来获得了广泛关注.这类方法综合了系统理论,线性代数和统计学三方面的思想,其特点是直接由输入输出数据辨识系统的状态空间模型,因而非常适合多变量系统辨识.首先介绍了SMI的基本思想, 然后分析了3种基本算法（N4SID、MOESP和CVA）的异同点、算法实现、统计特性和模型稳定性等方面.随后探讨了其他一些SMI算法,包括连续时间系统SMI算法、频域SMI算法、闭环SMI算法和非线性系统SMI算法.为说明SMI方法的特性,通过一个工厂实际例子研究对比了3种SMI基本算法和一种传统辨识算法——预测误差方法（PEM）.最后阐述了理论方面有待进一步研究的主要问题.     

Synthesis and characterization of polyurethanes containing arylene sulfone ether linkages

Polyurethanes containing arylene sulfone ether linkages were synthesized by solution polymerization of 4,4′-bis(4-isocyanatophenoxy)diphenylsulfone (SPI) and 4,4′-bis(3-isocyanatophenoxy)diphenylsulfone (SMI) with various aliphatic glycols such as ethylene glycol (EG), 1,2-propylene glycol (PG), 1,4-butylene glycol (BG), polyethylene glycol (PEG 300 and 1000), polypropylene glycol (PPG 300 and 1000) and polytetramethylene glycol (PTMG 1000. TERACOL) in dimethylacetamide (DMAC) at 120°C. The diisocyanates SPI and SMI were prepared from the corresponding diacid chlorides via Curtius rearrangement. The polyurethanes were obtained in high yields. The effect of structures of diisocyanate and aliphatic diols on the molecular weight and thermal properties of polyurethanes was also investigated. The polyurethanes prepared were characterized by infrared spectroscopy, solution viscosity, elemental analysis, thermogravimetric analysis and X-ray diffraction. Physical and thermal properties of polyurethanes prepared from SPI and various aliphatic glycols were compared with the polyurethanes from SMI and various aliphatic glycols.     

Skeletal Muscle Depletion Predicts the Prognosis of Patients with Hepatocellular Carcinoma Treated with Sorafenib

The aim of this study was to determine whether skeletal muscle depletion predicts the prognosis of patients with hepatocellular carcinoma (HCC) that is being treated with sorafenib. We evaluated 40 consecutive HCC patients who received sorafenib treatment. The skeletal muscle cross-sectional area was measured by computed tomography at the third lumbar vertebra (L3), from which the L3 skeletal muscle index (L3 SMI) was obtained. The factors contributing to overall survival, sorafenib dose reduction, and discontinuation of sorafenib were analyzed using the Cox proportional hazards model. L3 SMI (p = 0.020) and log (α-fetoprotein (AFP)) (p = 0.010) were identified as independent prognostic factors in HCC patients treated with sorafenib. The initial dose of sorafenib (p = 0.008) was an independent risk factor for sorafenib dose reduction, and log (AFP) (p = 0.008) was the only significant risk factor for the discontinuation of this drug. L3 SMI was not a risk factor for either dose reduction (p = 0.423) or the discontinuation (p = 0.132) of sorafenib. A multiple linear regression analysis determined the following relationship between skeletal muscle mass (assessed as L3 SMI) and the explanatory factors: L3 SMI = −0.1896 × (Age) − 10.3441 × (Child-Pugh score) − 9.3922 × (log (AFP)) + 1.6139 × (log (AFP)) × (Child-Pugh score) + 112.9166. Skeletal muscle depletion is inversely associated with age, Child-Pugh score, and log (AFP). Moreover, it is an independent prognostic factor for HCC patients treated with sorafenib.     

Effect of poly(styrene‐co‐maleic anhydride) imidization on the miscibility and phase‐separation temperatures of poly(styrene‐co‐maleic anhydride)/poly(vinyl methyl ether) and poly(styrene‐co‐maleic anhydride)/ poly(methyl methacrylate) blends

The objective of this work was to study the miscibility and phase‐separation temperatures of poly(styrene‐co‐maleic anhydride) (SMA)/poly(vinyl methyl ether) (PVME) and SMA/poly(methyl methacrylate) (PMMA) blends with differential scanning calorimetry and small‐angle light scattering techniques. We focused on the effect of SMA partial imidization with aniline on the miscibility and phase‐separation temperatures of these blends. The SMA imidization reaction led to a partially imidized styrene N‐phenyl succinimide copolymer (SMI) with a degree of conversion of 49% and a decomposition temperature higher than that of SMA by about 20°C. We observed that both SMI/PVME and SMI/PMMA blends had lower critical solution temperature behavior. The imidization of SMA increased the phase‐separation temperature of the SMA/PVME blend and decreased that of the SMA/PMMA blend. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Direct polymer reaction of poly(styrene‐co‐maleic anhydride): Polymeric imidization

Using direct polymer reaction of poly(styrene‐co‐maleic anhydride) (SMA), a synthesis of copolymer of styrene and N‐aryl succinimide (SMI) has been investigated. SMI copolymers were synthesized from SMA copolymers by a concerted two‐step reaction, which consisted of the condensation reaction (step 1) of SMA with aromatic amine to prepare a precursor, succinamic acid, for imide formation and the cyclodehydration reaction (step 2) of succinamic acid. In this article, the application of Searle's preparation method of N‐aryl or N‐alkyl maleimide to the direct polymer reaction for SMI was attempted. Compared with synthesis of monomeric imides, the imide formation in polymeric condition appeared to be a little more sensitive to the reaction condition. The optimum condition for maximum conversion was examined in terms of time, temperature, and the amount of reactants. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1187–1196, 1999     

Synthesis of poly(styrene-co-maleimide) and poly(octadecene-co-maleimide) nanoparticles and their utilization in paper coating

Aqueous polymer dispersions comprising of poly(styrene-co-maleimide) (SMI) or poly(octadecene-co-maleimide) (OMI) nanoparticles were synthesized by thermal imidization of the corresponding maleic anhydride copolymer precursors with ammonia using an organic solvent free process. Different reaction parameters such as temperature, time, agitation speed and stirrer geometry, and molar ratio of ammonia-to-anhydride were investigated in order to find optimal conditions. The obtained copolymer nanoparticles exhibited glass transition temperatures (T_g's) between 140 and 170 °C with particle sizes ranging from 50 to 230 nm. The compositional analysis was conducted by recording ¹H NMR and ATR-FTIR spectra. In addition, SMI dispersions were successfully spray dried and analyzed by SEM. Finally, the polymer dispersion's utility as auxiliary organic pigment in paper coating formulations was evaluated.     

Study on the thermal conductive polyoxymethylene/graphite composites

The thermal conductive composites of polyoxymethylene (POM)/graphite were prepared through four intercalation methods, including melt (MI), solution (SM), pan milling (SMI), and in situ intercalation (IM). For the purpose of improving the interfacial compatibility of POM/graphite, realizing the exfoliation and nano‐dispersion of graphite in POM matrix, the effect of the type and the content of the graphite, the nature of the coupling agents used in graphite modification on the properties of the composites was studied. The results showed that the thermal conductive properties of POM were improved remarkably from the value of 0.36 W/(m K) for neat POM to the value of 1.15 W/(m K) in presence of 30 wt % graphite, and the composites filled with the coupling agent T‐1 or T‐2 surface‐modified colloidal graphite displayed better thermal conductivity. The degree of layers exfoliation of the graphite was enhanced in the order of MI, SM, SMI, and IM. And the composites prepared by SM, SMI, and IM methods presented much more decreased size, more narrow size distribution, thinner overlapped sheets, and better dispersion of the graphite than that prepared by MI method. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis of poly(styrene-co-maleimide) and poly(octadecene-co-maleimide) nanoparticles and their utilization in paper coating

Aqueous polymer dispersions comprising of poly(styrene-co-maleimide) (SMI) or poly(octadecene-co-maleimide) (OMI) nanoparticles were synthesized by thermal imidization of the corresponding maleic anhydride copolymer precursors with ammonia using an organic solvent free process. Different reaction parameters such as temperature, time, agitation speed and stirrer geometry, and molar ratio of ammonia-to-anhydride were investigated in order to find optimal conditions. The obtained copolymer nanoparticles exhibited glass transition temperatures (T_g's) between 140 and 170 °C with particle sizes ranging from 50 to 230 nm. The compositional analysis was conducted by recording ¹H NMR and ATR-FTIR spectra. In addition, SMI dispersions were successfully spray dried and analyzed by SEM. Finally, the polymer dispersion's utility as auxiliary organic pigment in paper coating formulations was evaluated.     

SMI聚合反应釜传质及传热的研究

提出了SMI耐热改性剂在聚合反应前期的放热曲线,指出该反应的特点。在150 L的聚合反应釜内研究了影响SMI聚合反应的关键参数Pv、Np/Nqd及传热系数K,重现了小试试验的传热、传质结果。借助水运实验验证了经验公式计算传热效果的可靠性,理论计算值与实际值吻合较好,实现了聚合反应的可控性,为进一步放大研究提供了参考依据。     

Computational and Experimental Investigation of Immobilization of CuI Nanoparticles on 3-Aminopyridine Modified Poly(styrene-<Emphasis Type="Italic">co</Emphasis>-maleic anhydride) and Its Catalytic Application in Regioselective Synthesis of 1,2,3-Triazoles

Cu(I) nanoparticles (NPs) on modified poly(styrene-co-maleic anhydride) was prepared via a facile procedure. In this regard the modified co-polymer (SMA) was initially synthesized from the reaction of poly(styrene-co-maleic anhydride) with 3-aminopyridine. Upon the treatment of CuI with SMA, Cu(I) NPs were immobilized on SMA. This immobilized Cu(I) NPs was fully characterized by FTIR, SEM and EDAX analysis methods. Moreover, the interaction of Cu cations with 3-aminopyridine modified SMI catalyst via density functional theory (DFT) and quantum theory of atoms in molecules (QTAIM) computationally was studied. Our calculated results demonstrated that among 2,3 and 4 substituted aminopyridines for the modification of SMA, the 3-amnopyridine has the weakest ligand and Cu(I) interaction. However, the SMI image showed a suitable size of nanoparticles and inductively coupled plasma (ICP) analysis showed a higher Cu content in comparison with those of 2 and 4-substituted pyridines. The catalytic activity and reusability of this nanocatalyst system of 3-substituded aminopyridines was examined in the Huisgen 1,3-dipolar cycloaddition via click reaction. The reactions proceeded smoothly leading to regioselective synthesis of 1,4-disubstitued 1,2,4-triazole derivatives in excellent yields under mild reaction conditions. This heterogeneous catalytic system was separated easily by simple filtration and was reused without pre-activation at least in five runs without appreciable loss in its activity.