微乳液聚合制备聚丙烯酰胺及聚N-异丙基丙烯酰胺超细微粒

研究了琥珀酸双（２－乙基己酯）磺酸钠（ＡＯＴ）、甲苯（Ｔ）、乙酰胺（ＥＭ）、丙烯酰胺（ＡＭ）、Ｎ－异丙基丙烯酰胺（ＮＩＰＡＭ）、Ｎ,Ｎ－亚甲基双丙烯酰胺（ＢＩＳ）、水组成的六种微乳液体系,以电导法和目视法测定了其相区临界点电导率,并绘制了各自的拟三元相图;以偶氮二异丁腈（ＡＩＢＮ）为引发剂,在微乳液中制备了聚丙烯酰胺及聚Ｎ－异丙基丙烯酰胺超细微粒．用ＩＲ谱对其进行了验证,以扫描电镜观察了其外部结构特征,测得微粒平均粒径为０．０５～０．１０μｍ．实验表明,可在微乳液中制备ＰＡＭ及ＰＮＩＰＡＭ超细微粒．     

氧化还原引发聚合制备高吸水性树脂

采用氧化还原引发剂反相悬浮法制备部分中和丙烯酸丙烯酰胺共聚物吸水剂。当聚合温度为５０℃,时间为４．５ｈ,分散剂和引发剂用量分别占单体重量的３．５％和０．２１３％时,共聚物吸水率可达１６００ｇ／ｇ。     

新法合成氯乙酸异丙酯

以氯乙酸、异丙醇直接酯化制备氯乙酸异丙酯，使用Ｆｅ２（ＳＯ４）３·ｘＦ２Ｏ催化可简化产品后处理操作．得酯收率８３．８％．     

微乳液聚合聚N-异丙基丙烯酰胺超细微粒的结构表征

以偶氮二异丁腈为引发剂，在琥珀酸双（２乙基己酯）磺酸钠、甲苯、Ｎ异丙基丙烯酰胺、水组成的微乳液中，通过微乳液聚合制备了未交联及交联的聚Ｎ异丙基丙烯酰胺超细微粒．用扫描电镜、迎头色谱法及粘度法对其结构进行了表征．该超细微粒的颗粒平均粒径约０．１μｍ，未交联聚Ｎ异丙基丙烯酰胺粘均分子量为１．３８×１０６ｋｇ／ｍｏｌ，交联聚Ｎ异丙基丙烯酰胺超细微粒的内比表面积为４８．０４８ｍ２／ｇ，相对孔径分布为１～１０ｎｍ，气体最大吸附量为１７８４．８ｃｍ３／ｇ．     

Cancer Risk Estimation of Genotoxic Chemicals Based on Target Dose and a Multiplicative Model

A mechanistic model and associated procedures are proposed for cancer risk assessment of genotoxic chemicals. As previously shown for ionizing radiation, a linear multiplicative model was found to be compatible with published experimental data for ethylene oxide, acrylamide, and butadiene. The validity of this model was anticipated in view of the multiplicative interaction of mutation with inherited and acquired growth-promoting conditions. Concurrent analysis led to rejection of an additive model (i.e. the model commonly applied for cancer risk assessment). A reanalysis of data for radiogenic cancer in mouse, dog and man shows that the relative risk coefficient is approximately the same (0.4 to 0.5 percent per rad) for tumours induced in the three species.Doses in vivo, defined as the time-integrated concentrations of ultimate mutagens, expressed in millimol × kg^–1 × h (mMh) are, like radiation doses given in Gy or rad, proportional to frequencies of potentially mutagenic events. The radiation dose equivalents of chemical doses are, calculated by multiplying chemical doses (in mMh) with the relative genotoxic potencies (in rad × mMh^–1) determined in vitro. In this way the relative cancer incidence increments in rats and mice exposed to ethylene oxide were shown to be about 0.4 percent per rad-equivalent, in agreement with the data for radiogenic cancer.Our analyses suggest that values of the relative risk coefficients for genotoxic chemicals are independent of species and that relative cancer risks determined in animal tests apply also to humans. If reliable animal test data are not available, cancer risks may be estimated by the relative potency. In both cases exposure dose/target dose relationships, the latter via macromolecule adducts, should be determined.     

丙烯酰胺类聚合物合成用引发体系研究进展

丙烯酰胺类聚合物合成用新型引发剂是近年提高聚合物分子量研究的热门课题之一，讨论了水溶性偶氮引发剂的聚合性能、特点及应用范围，认为水溶性偶氮引发剂可用于制备高分子量的丙烯酰胺类聚合物及其衍生物，应用前景好；讨论了双官能度引发剂和含胺基功能性单体引发剂对聚合物分子量的影响，认为由过硫酸钾、氨水、尿素、偶氮-（2-脒基丙烷）盐酸盐及功能性单体 MP 构成的低温新型复合引发体系可制备超高分子量的丙烯酰胺类聚合物。