粘度法研究高分子溶液行为的实验改进

用Ｕｂｂｅｌｏｈｄｅ式粘度计测定高分子溶液粘度设备简单,操作便利,有相当好的实验精确度,是表征聚合物分子量有效手段之一,在高分子工业生产和实验室得到最广泛使用［１］．它还可以用来研究高分子在溶液中的形态、高分子链的无扰尺寸、高分子链的柔性程度、支化高...     

桐油预聚物改性沥青

将桐油用无水AlCl3引发聚合为低分子预聚物,预聚物再与沥青继续进行聚合反应以对其改性。改性后的沥青针入指数和低温延度均有改善。用红外、特性粘接[η]及薄层色谱方法对预聚反应、聚合度及改性沥青进行了分析。发现预聚物主要与沥青中的胶质、沥青质发生了反应。反应物可以作为界面剂增加沥青中其它组分的相容性。在沥青质上加成桐油预聚物后,可以克服其刚性强、互容性差的缺点,对稳定沥青的胶体结构、改善沥青的针入指数、低温延度有较好作用。桐油预聚体在沥青混合物中的质量分数为3％－6％时沥青可具有较好的性能改善结果。     

溶剂性能对部分解缠结聚氯乙烯有序结构形成的影响

一般的高分子非晶态是线团相互穿透的多链凝聚态,是分子固体中非常独特的一种分子凝聚态[1～4].而高分子链的缠结是高聚物凝聚态的重要特征之一.缠结是指高分子链之间形成物理交联点,构成网络结构,使分子链的运动受到周围分子的羁绊和限制[5],因此缠结对链的构象调整以及链单元     

“高分子物理”及“高分子物理实验”2门精品课程的建设

"高分子物理"(在中国科学技术大学叫"高聚物的结构与性能")和"高分子物理实验"课是该校高分子科学与工程系本科生的必修课。为了讲好和全面建设这两门课,作者倡导并积极开展教学研究,发表39篇教学研究论文,作者把这些研究心得和成果及时引入教学中,先后编写和出版了十几本教材及教学参考书,教学质量不断提高,并逐步形成了有鲜明特色的教学,在国内高校产生了很好的影响。通过多方面的建设,2005年"高聚物的结构与性能"被评为国家级精品课程,2006年"高分子物理实验"被评为安徽省精品课程。     

高分子溶液剪切增稠行为、机理及应用

综述了具有剪切增稠性质的高分子溶液及其流变行为,分析了高分子溶液剪切增稠的机理,讨论了高分子浓度、分子量和高分子组成等对剪切增稠高分子溶液流变行为的影响,最后介绍了高分子剪切增稠体系在石油开采、抗冲减振及日用化工等领域的应用。     

Effect of ortho-methoxycinnamic acid on the sol-gel transition of methylcellulose solutions in the presence of cetyltrimethylammonium bromide

The sol-gel transition of methylcellulose (MC) solutions in the presence of ortho-methoxycinnamic acid (OMCA) or cetyltrimethylammonium bromide (CTAB) and in the coexistence of OMCA and CTAB was determined by the rheological measurement. It has been found that the sol-gel transition temperature of MC solutions increases linearly with the concentration of either OMCA or CTAB in solution, respectively. However, in the coexistence of OMCA and CTAB, the sol-gel transition temperature of MC solutions remains invariable, independent of the concentration of CTAB in solution. The experimental results show that OMCA has priority to adsorb on the methyl group of MC chains to form polymer-bound aggregates. In particular, these aggregates inhibit the hydrophobic interaction between CTAB and the methyl group of MC chains completely. Taking into account the fact that OMCA is almost insoluble in MC-free solutions but dissolves very well in aqueous MC solutions, we propose the formation of the core-shell architecture prompted by OMCA and the methyl group of MC chains, with the methyl group of MC chains serving as the core and the self-assembly of OMCA molecules serving as the shell. Obviously, the formation of the core-shell structure increases the solubility of OMCA, improves the stability of methyl groups of MC chains at high temperatures and inhibits the hydrophobic interaction between CTAB and the methyl group of MC chains in solution. The abnormal behavior relating to the sol-gel transition of MC solutions in the presence of OMCA or in the coexistence of OMCA and CTAB is therefore explained. Upon UV irradiation, the sol-gel transition temperature of MC solutions in the presence of OMCA, or in the coexistence of OMCA and CTAB, decreases notably. However, the dependence of the sol-gel transition temperature of MC solutions as a function of OMCA concentration, or CTAB concentration in the presence of OMCA, does not change after UV irradiation.     

四甲基溴化铵及不同链长表面活性剂对甲基纤维素-邻甲氧基肉桂酸溶液凝胶化行为的影响

测定了四甲基溴化铵以及表面活性剂十二烷基三甲基溴化铵(DTAB)、十四烷基三甲基溴化铵(TTAB)和十六烷基三甲基溴化铵(CTAB)对甲基纤维素(MC)-4邻甲氧基肉桂酸钠盐(OMC-)体系的凝胶化行为的影响.结果表明:含DTAB、TTAB以及CTAB的MC-OMC溶液的溶胶-凝胶转变温度不随表面活性剂质量分数的变化而变化,但是向MC-OMC溶液中加入四甲基溴化铵,体系的溶胶-凝胶转变温度会显著下降.在含四甲基溴化铵或不同链长表面活性剂的MC-OMC-溶液中,TTAB等表面活性剂分子更倾向于在水溶液中形成球状胶束;四甲基溴化铵与OMC-有着较强的静电作用,会导致MC和OMC-形成的核-壳结构破裂.     

高分子的θ溶液

θ溶液是高分子溶液中的理想溶液。本文简要介绍了高分子θ溶液在高分子溶液研究中的重要性 ,对高分子θ溶液的本质以及它与真正的理想溶液的差别作了较为详细的讨论