漆酚硼衍生物的研究(Ⅳ)──硼酸漆酚酯的聚合反应

硼酸漆酚酯具有较漆酚更易聚合的特性。根据元素分析、热分析、红外光谱、紫外光谱、核磁共振氢谱和电子自旋共振谱等的测试结果认为：硼酸漆酚酯的聚合反应发生于其不饱和侧碳链基上；该不饱和碳链基在干燥空气中进行游离基聚合；其分子中的硼原子对该游离基聚合反应具有催化作用。     

Dough rheological properties and noodle-making performance of non-waxy and waxy whole-wheat flour blends

Dough rheological properties and noodle-making performance of non-waxy whole-wheat flour (WWF) with partial- or full-waxy (PW- or FW-) WWF substitution were studied. The substitution levels were 0, 250, 500, 750, and 1000 g/kg, respectively. FW-WWF reduced the peak viscosity and pasting temperature of WWF blends as its substitution level was increased due to its higher proportions of B-type starch granules and short amylopectin chains, while PW-WWF increased peak viscosity with the increasing substitution level because of its higher amylopectin content. As demonstrated by farinograph and rheometer measurements, FW-WWF interfered with gluten development because of the increased competition for water by arabinoxylans and amylopectin; however, PW-WWF enhanced dough strength due primarily to its increased protein content. Consequently, FW-WWF showed a detrimental effect on cooked noodle texture as the cooked noodle hardness was reduced by 50% at the 1000 g/kg substitution level. In contrast, PW-WWF enhanced noodle integrity and elasticity by increasing cooked noodle cohesiveness and resilience by 10.1% and 14.8%, respectively, at the 1000 g/kg substitution level. The results suggest that with waxy WWF substitution, the changes in starch composition, arabinoxylans, and protein content could modify the interactions among flour components and influence the quality characteristics of noodle products.     

乳酸介质中麦草浆纤维素的降解及其结构的变化

[目的]为利用纤维素制备热塑性高分子材料提供依据。[方法]在一定温度下,将预处理后的原料（干燥麦草浆）浸入一定量的乳酸中,搅拌一定时间后干燥至恒重,研究温度、时间对纤维素聚合度和碘吸附值的影响,并分析麦草浆纤维素在乳酸介质中化学结构的变化。[结果]温度高于30℃时,纤维素开始降解,且温度越高,纤维素降解越剧烈。温度和搅拌时间对纤维素聚合度和碘吸附值的影响较大,而乳酸用量对其影响较小。红外谱图和X-衍射图谱分析结果表明,60℃之前,麦草浆在乳酸介质中主要发生物理溶胀和少量的降解;超过70℃后,麦草浆除发生降解外,还可能伴随着化学反应,但纤维素的晶型未发生改变。[结论]该研究为纤维素在乳酸介质中的改性提供了资料。     

树脂酸聚合反应过程的研究

研究了用凝胶色谱法测定树脂酸聚合反应中二聚体含量的分析方法,并结合对其中未聚树脂酸的气相色谱分析,研究了以硫酸为催化剂、氯仿为溶剂时,树脂酸异构、聚合、氧化、歧化诸反应及其相互关系。实验结果表明:枞酸型树脂酸的异构反应速度大于聚合反应速度。聚合反应的进行不影响异构反应的平衡。在硫酸的作用下,少量树脂酸发生歧化反应,但大量去氢枞酸的产生,主要是由于硫酸的氧化作用。实验中没有观察到空气中的氧对反应有影响。本文还较详细地研究了枞酸的异构—聚合反应动力学,根据动力学数据,求得了反应速度常数及活化能,并提出了枞酸异构——聚合反应可能的机理。     

Pyrolysis behavior of levoglucosan as an intermediate in cellulose pyrolysis: polymerization into polysaccharide as a key reaction to carbonized product formation

Pyrolysis behavior of levoglucosan (1,6-anhydro--d-glucopyranose), the major anhydromonosaccharide formed during cellulose pyrolysis, was studied at 250°–400°C under nitrogen. The pyrolysis products were found to change stepwise: levoglucosan MeOH-soluble fraction (lower-molecular-weight products and oligosaccharides) water-soluble fraction (polysaccharides) insoluble fraction (carbonized products). From the present experimental results, a pathway of cellulose pyrolysis via anhydromonosaccharide is proposed including polymerization to polysaccharides (a reversible reaction) as a key reaction to carbonized product formation.Part of this study was presented at the XIXth International Carbohydrate Symposium, San Diego, August 1998; and the 50th Annual Meeting of the Japan Wood Research Society, Kyoto, April 2000     

Studies on the synthesis and properties of terpene-phenol-aldehyde resin with a high softening point

Synthesis conditions of terpene-phenol-aldehyde resin with a high softening point were studied based on the reactions among-pinene, phenol, and formaldehyde. A suitable catalyst system and the best processing conditions were obtained by laboratory experiments. The influence of the raw materials ratios, reaction temperature, reaction time, and catalyst dose on the softening point, yield, and color of the synthesized resin was examined. The physical and chemical characteristics of the resin were determined: softening point 140°C (ball and ring method); color value 7 (Gardner); acid value (KOH mg/g) <1; bromine value (Br₂ mg/100g) <64; saponification value (KOH mg/g) <1; average molecular weight 830. The yield of resin was more than 85% (based on the total raw material).     

聚合杂交育种在“扬油系列”新品种选育中的应用

针对油菜优质育种初期优质与高产的矛盾，使用“结合株型结构理论、注重亲本选配、使用聚合杂交、低世代系谱选择、高世代集团选择”的育种方法和思路，“十五”期间选育出了一批产量、品质同步提高的优质常规甘蓝型油菜新品种。这些新品种突出特性为：产量水平较高，各期营养生长旺盛，植株较高，产量结构协调，每株有效角果数较多，结角层为华盖式或近似华盖式结构；品质指标较优；抗逆性较强。实践证明，聚合杂交育种在常规甘蓝型油菜育种中的正确使用，有利于同步提高常规甘蓝型油菜的产量和品质，也证明了常规油菜产量水平仍有进一步提高的空间。     

α－蒎烯等离子体聚合反应机理研究

应用ＧＣ－ＭＳ、ＰＧＣ－ＭＳ、ＥＳＲ和ＩＲ等分析方法测定了α－蒎烯等离子体聚合过程中气相产物的组成及其聚合物结构。根据分析结果，提出ａ－蒎烯等离子体聚合机理是自由基聚合反应机理。     

大孔吸附树脂HP-20分离肉桂原花青素的研究

[目的]研究HP-20大孔吸附树脂分离肉桂原花青素。[方法]采用HP-20大孔吸附树脂分离肉桂原花青素,将1 g原花青素原料溶解在少量60%乙醇中,制得的浓溶液匀速加入吸附柱中,分别用20%、40%、60%、80%、100%的乙醇对吸附在树脂上的肉桂原花青素进行梯度洗脱,并分析各部分质量、纯度以及聚合度。[结果]各部分样品分别标记为F20、F40、F60、F80、F100,五部分的质量分别为0.24、0.19、0.17、0.27、0.02 g;五部分中,纯度最高的为F40部分,纯度为82.65%,纯度最低的为F100部分,纯度为65.11%;洗脱过程中原花青素回收率达89%;分析各浓度的乙醇洗脱液中原花青素平均聚合度发现,10%~40%乙醇洗脱液中主要为低聚体,而40%~100%乙醇洗脱液中主要为高聚体。[结论]该研究为下一步肉桂原花青素高聚体的降解后的分离提供理论依据。     

二聚环戊二烯树脂的合成及其性能的研究

以试剂级和工业级的二聚环戊二烯为原料，探讨其树脂的合成工艺，研究阳离子聚合反应的规律，选出较为理想的催化剂体系，确定了适宜的工艺条件。采用甲苯为溶剂，以Ｃａｒ－Ⅲ为催化剂，其用量为３．５％－４．０％，溶剂比为１：１．３，在－５－０℃下进行反应，反应物经过水解，过滤，水洗和蒸馏等工序，得到浅黄色树脂。