聚烯烃老化的时空谱--多因素耦合老化动力学研究

聚烯烃的自然老化是光照、温度、湿度和氧气多种环境因素综合作用的结果,但长期以来,无法通过实验室加速得到模拟综合条件下的老化结果.本文采用自主设计开发的多因素耦合老化评价系统,可以实现光照、温度、湿度和氧气条件的可控加载,测定高分子材料在不同条件组合下老化时产生的气相降解产物(如CO_(2))的生成速率,以此来评价材料的稳定性.以聚丙烯(PP)和聚乙烯(PE)为典型体系,建立了二者关于温度、光照强度、湿度和氧气浓度的单因子老化速率方程,并基于此建立了PP和PE的多因素耦合老化动力学模型.通过测定不同条件下的老化速率,拟合得到了PP和PE的多因素耦合老化动力学方程,并计算得到了PP和PE的全国“老化速率地图”和逐月“老化速率时间谱”,对PP和PE的应用提供了重要的指导.进行了PP和PE对不同条件因子的敏感性分析.研究发现,PP对光照强度和湿度的敏感性显著高于PE,对氧气浓度的敏感性略高于PE,而对温度的敏感性要低于PE.

Design,synthesis and insecticidal activity of spiro heterocycle containing neonicotinoid analogs

Spiro heterocycles frequently occur in bioactive molecules. In the pursuit of neonicotinoids with spiro hererocycles, three types of novel neonicotinoids with spirobenzofuranone, spirooxindole or spiroacenaphythylenone framework were designed and synthesized. Insecticidal evaluation showed that some of spirobenzofuranone containing neonicotinoids exhibited moderate activity against cowpea aphid, armyworm or brown planthopper.

Facile three-component synthesis and insecticidal evaluation of hexahydroimidazo[1,2-a]pyridine derivatives

A series of new hexahydroimidazo[1,2-a]pyridine derivatives were synthesized via convenient and practical three-component reactions. Preliminary bioassays showed that majority of the target compounds exhibited moderate to excellent insecticidal activity against cowpea aphids （Aphis craccivora）. Among them, compound 91 demonstrated significant activity with LCso value of 0.00918 mmol/L which was about 3.8-fold higher than that of imidacloprid （IMI）. Furthermore, the study of stereostructure-activity relationship of four isomers of 9k indicated that configuration played a key role in insecticidal activity of these compounds.

Synthesis and insecticidal evaluation of tetrahydroimidazo[1,2-a]pyridin-5(1H)-one derivatives

A series of novel tetrahydroimidazo[1,2-a]pyridine-5（1H）-one derivatives containing a electronegative pharmacophore（=CNO_2） were synthesized via practical aza-ene reaction and characterized by ~1H NMR,^（13）C NMR,^（19）F NMR and HRMS. Preliminary bioassays showed that some of the target compounds exhibited good insecticidal activity against brown planthopper（Nilaparvata lugens） and cowpea aphids（Aphis craccivora） at 500 mg L^（-1）. Among them, compound 11 h was active against brown planthopper at100 mg L^（-1）. The insecticidal activities varied significantly depending on the types and patterns of the substituents, which provided guidance for further investigation on structure modifications.

Synthesis and insecticidal activities of novel bridged-neonicotinoids

A series of novel bridged-neonicotinoid analogues were designed and synthesized, which were constructed by starting material 8 with cyclopentenone or cyclohexenone in the presence of catalyst aluminium chloride. All of the compounds were characterized and confirmed by^1H NMR,^（13）C NMR, HRMS and IR. The bioassay tests showed that compounds 5 and 6a showed higher bioactivities than imidacloprid against Aphis craccivora.