AMPS/AM/木薯淀粉接枝共聚物制备工艺的研究

研究了2-丙烯酰胺基-2-甲基丙磺酸(AM PS)、丙烯酰胺(AM)与木薯淀粉接枝共聚物的接枝共聚工艺条件。结果表明单体用量、引发剂用量、反应温度和反应时间对单体转化率、接枝率、接枝效率有较大影响,制备的AM PS/AM/木薯淀粉接枝共聚物具有较好的吸水性能。     

The graft copolymerization of corn starch by microwave irradiation with rheological phase reaction

The corn starch was grafted by microwave irradiation with rheological phase reaction, to meet the sizing requirements of polyester/cotton blended yarn and avoid the disadvantages of corn starch size including brittle, hard, and size shedding. On the basis of the damping characteristics of corn starch film and the polarity of grafting monomer, the grafting effect of grafted corn starch was researched by using infrared spectroscopy, SEM, rotary viscometer, and thermomechanical analyzer. The results showed that both hydrophilic groups and hydrophobic groups were introduced in the molecular chains of grafted corn starch. The storage modulus of grafted corn starch film reached 285–315 MPa, being four times higher than that of nongrafted corn starch film. Compared with corn starch sizing, the viscosity of grafted corn starch sizing decreased 62.5%. Furthermore, through analyzing grafting law and establishing regression equation, it was indicated that the irradiation time and initiator content influenced the grafting ratio of grafted starch significantly. The grafting ratio could reach 19.57%, when the irradiation time and initiator content were selected with 3.5 min and 4.55%, respectively. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

HRP催化淀粉与酚类接枝聚合物的合成研究

以辣根过氧化物酶(HRP)/H2O2为催化体系,催化降解淀粉和3,5-二羟基苯甲酸(3,5-DBA)进行自由基接枝共聚反应,合成了淀粉和酚类接枝共聚物。探讨了温度和pH对酶活力的影响以及接枝条件对接枝共聚反应的影响。通过FTIR、1HNMR和GPC对接枝改性淀粉的化学结构进行了表征。产物用作皮革鞣剂时,显示了良好的应用性能。     

玉米淀粉接枝丙烯酰胺制备高吸水性树脂

用硝酸铈铵作引发剂,通过水溶液聚合法制得了玉米淀粉接枝丙烯酰胺高吸水性树脂。研究了交联剂及引发剂用量、碱用量、反应温度以及反应时间等对吸水率的影响。得到的最佳反应条件为:交联剂和引发剂与丙烯酰胺的摩尔比分别为1.0×10-5和3.0×10-3,碱与丙烯酰胺的摩尔比为1.50,反应温度60℃,反应时间2 h。在室温下制得的高吸水树脂,30 m in每克吸蒸馏水和自来水分别约为其自身质量的600和170倍。     

淀粉接枝丙烯酰胺絮凝剂的制备和应用

以可溶性玉米淀粉和丙烯酰胺为原料,高锰酸钾/草酸为引发剂,制备了淀粉接枝丙烯酰胺聚合物絮凝剂,考查了淀粉与丙烯酰胺质量比、引发剂质量、反应温度、反应时间等对接技效率的影响。结果表明淀粉与丙烯酰胺质量比为1:2,引发剂质量为0.35g,50℃反应3h接枝效率最高,处理高岭土溶液有较好的絮凝效果。     

正交设计在合成玉米淀粉接枝丙烯酸共聚物中的应用

以过硫酸铵为引发剂,N,N’-亚甲基双丙烯酰胺为交联剂,在玉米淀粉上接枝丙烯酸制备高吸水性树脂。用正交实验,采用L16(45)正交表,考察了丙烯酸的中和度、淀粉与单体比例、引发剂、交联剂等对高吸水性树脂吸水率的影响。制得的树脂吸纯水率可达1 300 g/g,吸质量分数为0.9%NaCl溶液90倍,有较好的热稳定性。     

玉米淀粉胶粘剂的研制

采用高锰酸钾作氧化剂,经氧化,糊化,交联等步骤,可于室制备出一种粘度适中,粘性,流动性及稳定性好的玉米淀粉胶粘剂。通过实验,确定了高锰酸钾,氢氧化钠,硼砂的最佳用量分别为0．8－1．6,10,0．5－1．0份（100份淀粉中加入量）,水与淀粉的最佳质量比为6：1－6．5：1。     

膨化玉米淀粉胶粘剂的研制

玉米经脱皮、破渣、提脐、用明矾、硼砂水溶液处理后,在膨胀化机中于２２５℃,０．７５ＭＰa压力下膨化,膨化后的玉米经粉碎、过筛、即得膨化玉米淀粉,本文介绍了膨化玉米淀粉的制备方法,讨论了温度、压力、含水率等对膨化率的影响,找出了最佳实验条件。     

微波辐射下淀粉-丙烯酰胺接枝共聚物的合成

以硝酸铈铵作为引发剂、丙烯酰胺为单体,用微波辐射法合成了淀粉接枝丙烯酰胺共聚物。探讨了反应时间、引发剂浓度、单体和淀粉质量比和反应温度等因素对接枝反应的影响。正交实验确定的最优工艺条件为:反应时间20 m in,引发剂浓度4 mmol/L,丙烯酰胺和淀粉质量比2.5∶1,反应温度55℃,最高接枝率和接枝效率分别达到211.6%和74.3%。     

SMAS/AM/淀粉抗温接枝共聚物的研究

研究了甲基丙烯磺酸钠(SMAS)、丙烯酰胺(AM)与淀粉接枝共聚物的合成方法，接枝反应的影响因素和热稳定性。实验结果表明，该接枝反应基本符合自由基反应的一般规律，并且其聚合产物具有明显的抗高温能力。     

Comparative disintegrant activities of breadfruit starch and official corn starch

A Comparative evaluation of starch powder extracted from breadfruit (Artocarpus communis, Frost) as tablet disintegrant was made with corn starch BP using a 2 × 4 factorial experiment in a randomized complete block design. Two factors (type of starch: 2 i.e. breadfruit and corn) at four levels (concentrations of starch disintegrant: 4 i.e. 2.5%, 5%, 7.5% and 10%) were studied. One (1) kilogram batches of paracetamol granules containing various concentrations of endo-disintegrant or exo-disintegrant were prepared by the wet granulation method in a combined mixer-granulator, using polyvinyl pyrrolidone solution as binder. Tablets were tested for disintegration, dissolution and physical qualities following the British Pharmacopoeia (BP) compendial procedures.At the compression force of 1 tonne, corresponding to average packing fraction of 0.92, all formulations containing breadfruit and corn starch exo-disintegrants passed the official disintegration time limit of ≤ 15 min and quantity dissolved (Q₃₀) of ≥ 80% in 30 min. As endo-disintegrant however, only corn starch at 5% and 10% w/w and breadfruit at 10% passed the BP limit test. Generally, the rank order of effectiveness of disintegrant was Corn_exo ≈ Breadfruit_exo > Corn_endo > Breadfruit_endo. The observed concentration-dependent difference in disintegrant effectiveness is ascribed to the differences in their hydration capacity and effective tablet porosity. Contrary to faster disintegration suggested by its higher hydration capacity, breadfruit starch formulations showed longer disintegration time than corn, attributable to the higher density of breadfruit formulations which appears to retard entry of disintegration fluid into the tablet. However, the dissolution profiles (Q₃₀) were comparable (p > 0.05).Breadfruit starch powder appears to be a suitable substitute for official corn starch only as exo-disintegrant in paracetamol tablet formulation. In that form, it not only produced rapid tablet break-up and drug dissolution, it also improved tablet crushing strength.     

Rapid Synthesis of MMA Grafted Pine Needles Using Microwave Radiation

Cellulose-graft-poly (methylacrylate) copolymers were prepared by microwave assisted free radical polymerization to develop an efficient rapid way to alter the surface properties of the cellulosic fibers. The effect of microwave radiation doses, ratio of monomer, solvent and initiator concentrations were determined to get the highest percentage of grafting. The graft copolymers were characterized by FTIR and SEM studies. The results clearly demonstrate that graft polymerization successfully occurred onto the cellulose backbone. The cellulose-graft-poly (methylacrylate) copolymers have been found to be more water- and moisture-resistant as well as also revealing enhanced chemical and thermal resistance.     

吸水性淀粉接枝共聚树脂

介绍了吸水性淀粉接枝共聚树脂的制备方法,主要特点,吸水机理及其在农业,医疗卫生,工业及环保中的应用。     

SBS／MMA／BA／MAA四元接枝共聚及其产物粘接性能

研究了SBS与甲基丙烯酸（MAA）和甲基丙烯酸甲酯（MMA）,丙烯酸丁酯（BA）的四元接枝共聚,探讨了MMA／BA质量比,MMA与BPO用量,反应时间,反应温度及固化时间对粘接性能的影响,并将该四元接枝胶的性能与三元胶和SBS／MMA／BA／AA四元胶进行了比较,结果发现：该四元胶对聚烯烃的粘接强度及室温固化性能优于SBS／MMA／BA三元胶,尤其与异氰酸酯配合使用时,其效果更佳,而且该四元胶的粘接强度,耐水及耐热性能均优于SBS／MMA／BA／AA四元胶。     

淀粉的预处理方法对其接枝共聚的影响

目前淀粉的预处理方法主要有物理法、化学法和生物降解法,如糊化、挤压、辐射、超声波、氧化、酸解和酶解等;通过研究不同的预处理方式对淀粉的结构、接枝共聚参数及其接枝共聚物性能的影响,从而可以优化接枝产品的性能。     

玉米淀粉接枝丙烯酸制备高效吸水树脂的研究

本文在紫外光照射下以芬顿试剂为引发剂,制备玉米淀粉接枝丙烯酸高效吸水树脂。通过单因素法考察了中和度、淀粉与丙烯酸质量比、交联剂及引发剂用量等因素对反应的影响,并通过红外光谱分析仪(FT-IR)对产品结构进行表征。实验结果表明:在N2保护下淀粉乳浓度为5.88%,丙烯酸与淀粉的质量比为1.3∶1,引发剂用量和交联剂用量占淀粉的质量百分数分别为5.00%和2.00%,聚合温度为40℃,聚合反应时间为1h,中和度为65%,所制备淀粉吸水树脂的吸水倍率可达到631g·g-1。     

反相乳液五元体系淀粉接枝共聚反应动力学

研究了在淀粉/单体/乳化剂/油/水五元反相乳液体系中引发淀粉和丙烯酰胺接枝共聚反应的动力学,考察了引发剂和乳化剂浓度、单体和淀粉浓度、反应温度等因素对表观聚合速率的影响.结果表明：在本实验考察范围内单体浓度和淀粉浓度对聚合速率影响明显,聚合过程中快速链终止和慢速链终止反应同时存在,动力学关系式为：R_p∝［I］^0.93［M］^1.28［St］^1.47［E］^0.61,聚合速率随体系温度的升高而加快,在35～55℃范围内,聚合反应的表观活化能为82.01 kJ•mol^-1.     

Preparation and properties of isocyanate prepolymer/corn starch adhesive

Utilizing corn starch as a main raw material to prepare starch adhesive, polyvinyl alcohol, borax, and carboxymethyl cellulose (CMC) were added in the preparation process. Because of the poor water resistance of native starch adhesive, an isocyanate prepolymer as a cross-linking agent was synthesized and added to improve its water resistance. Three-layer wood panels were fabricated and bonding strength was measured. The differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and energy dispersive X-ray spectroscopy (EDX) were used to characterize the thermal properties, morphology, and element content of samples. Effects of R value (the molar ratio of isocyanate group to hydroxyl group) and CMC addition on the physicochemical properties of starch adhesive were investigated. Thermal analysis results showed prepolymer/starch adhesive (PSA) cured at a relatively low temperature and thermal stability was improved after prepolymer added. SEM, XPS, and EDX results revealed that prepolymer played an effective role in bonding process, and the penetration of adhesive occurred in the wood, resulting in the improvement of bonding strength.     

淀粉接枝共聚物瓦楞纸表面施胶增强剂的制备及其应用

利用无皂乳液聚合技术通过阳离子淀粉和苯乙烯(St)、丙烯酸丁酯(BA)等乙烯基单体进行接枝共聚反应,制备了一种淀粉接枝聚合物乳液,并对其表面施胶性能进行了研究。结果表明:当m(淀粉接枝乳液)∶m(氧化淀粉)=3∶100、w(硫酸铝)=0.4%和施胶液pH=4时,其应用效果好且性价比高;淀粉接枝乳液的施胶性能优于氧化淀粉和接枝单体共聚物。     

固定化HRP/H2O2/ACAC酶促体系引发下降解淀粉接枝丙烯酰胺共聚物的合成与表征

以壳聚糖为载体、戊二醛为交联剂制备固定化辣根过氧化物酶（HRP）,采用固定化HRP/H₂O₂/乙酰丙酮（ACAC）酶促体系制备降解淀粉-丙烯酰胺接枝共聚物（St-g-PAM）,通过红外光谱、紫外光谱、核磁共振和电镜扫描等手段对接枝共聚产物进行了结构分析。结果表明,丙烯酰胺成功接枝在降解淀粉上。共聚物用做皮革复鞣剂进行了应用实验,应用结果表明复鞣后的革柔软、纤维分散好和选择填充性强。