低凝胶羧基丁腈橡胶的合成

以丁二烯(Bd)、丙烯腈(AN)及不饱和羧酸为聚合单体,采用低温三元乳液共聚技术合成了羧基丁腈橡胶,并研究了第3单体种类及配比、调节剂用量、加入方式和转化率等对聚合反应及产品性能的影响,采用红外光谱对产品进行了表征。结果表明,第3单体采用甲基丙烯酸时聚合反应更加平稳,采用分批加入调节剂的方式有利于凝胶控制,转化率控制在78%~82%较为适宜。     

固体沥青改性用丁苯胶乳的工艺研究

以丁二烯和苯乙烯为单体,采用阴离子乳化体系,在过氧化物与亚铁盐构成的氧化还原引发体系作用下,合成了性能良好的固体沥青改性用丁苯胶乳,讨论了影响聚合过程及胶乳性能的因素。结果表明,单体配比、乳化剂浓度、引发剂浓度、分子质量调节剂用量及聚合温度是控制丁苯胶乳性能的关键因素,分批加入乳化剂及梯度控温有利于控制胶乳门尼粘度和结...     

三元共聚物的聚合物组成影响因素研究

通过在丁苯乳液聚合过程中加入第三单体异戊二烯得到苯乙烯-异戊二烯-丁二烯三元共聚物,并通过改变实验条件研究了聚合转化率、聚合温度、引发剂用量、调节剂用量和单体配比等因素对聚合物组成的影响。结果表明,聚合时各单体投入量是影响聚合物组成的主要因素;其次,转化率的升高和聚合温度的升高会导致聚苯乙烯含量增加和聚异戊二烯含量减少。     

影响乳聚丁苯橡胶门尼粘度的因素

本文论述了乳聚丁苯橡胶合成过程中,分子量调节剂TDM的加入方式,单体总转化率以及聚合速率等因素对生胶门尼粘度(ML_(1+4)~(100℃)的影响,同时对分子量分布、凝胶含量、特性粘度与门尼粘度的关系也做了研究。     

回用水对生产丁苯橡胶聚合的影响及其应对措施

研究了将丁苯橡胶装置苯乙烯回收单元在脱除苯乙烯时产生的冷凝水用于生产丁苯橡胶1500时对聚合过程和产物性能的影响,并提出了应对措施。结果表明,苯乙烯回收单元汽提塔在生产平稳时冷凝水的水质稳定;占总用水质量分数30%的冷凝水被回用于聚合体系时使反应时间延长,产物门尼黏度偏高,力学性能不佳;无回用水时的聚合规律为随着反应温度升高、转化率控制在中下限及引发剂和调节剂用量适当增加,产物的门尼黏度呈下降趋势;据此,调整反应温度为(6.5±0.5)℃,控制转化率为(68±2)%,引发剂用量为0.075份(质量),调节剂用量为0.29份(质量)且分2次加入,占总用水质量分数30%的回用水对聚合过程和产物性能的影响可基本消除。     

ESBR1712基础胶乳门尼黏度的影响因素研究

通过乳聚法合成了充油乳聚丁苯橡胶SBR1712基础胶乳,研究了引发剂加入量、聚合转化率、相对分子质量调节剂加入量及加入方式对SBR1712基础胶乳门尼黏度的影响。结果表明,在相同转化率条件下,随着引发剂用量的增大,基础胶乳的门尼黏度逐渐降低;随着聚合转化率的提高,胶乳的门尼黏度上升;随着相对分子质量调节剂用量的增加,基础胶乳门尼黏度逐渐降低;相对分子质量调节剂一次加入的胶乳门尼黏度随转化率升高波动较大,而分批加入相对分子质量调节剂胶乳的门尼黏度较稳定。     

羟基偶氮酯引发剂合成双端羟基聚苯乙烯

以偶氮二异丁腈 ,乙二醇为原料合成双 ( 2 -羟乙基 ) 2 ,2′ -偶氮二异丁酸酯。将其作为引发剂 ,合成了遥爪型羟端基聚苯乙烯 ,其分子量为 3 .0× 10 3～ 6 .5× 10 3。讨论了单体浓度、引发剂浓度、聚合反应温度及反应时间对聚合转化率和产物分子量的影响。结果表明 ,聚合转化率和产物分子量随着单体浓度的增加而增加 ;而引发剂浓度增加 ,则聚合转化率明显提高 ,分子量却随之下降 ;温度升高 ,聚合转化率增加 ,产物分子量下降 ;而反应时间主要影响聚合转化率 ,对分子量影响不大。     

3-溴甲基-3-甲基氧杂环丁烷均聚物的合成及表征

以1,4-丁二醇(BDO)为引发剂,三氟化硼乙醚络合物(BF3·Et2O)为催化剂,3-溴甲基-3-甲基氧杂环丁烷(BrMMO)为单体,CH2Cl2为溶剂,按阳离子开环聚合机理,合成出有机黏合剂3-溴甲基-3-甲基氧杂环丁烷均聚物(PBrMMO).研究了低温条件下单体转化率随时间的变化情况,得出BrMMO转化率-时间曲线,考察了催化剂用量和反应体系温度对可控聚合的影响,确定出BrMMO可控聚合的最佳条件:BF3·Et2O与BDO的摩尔比为0.5∶1.0,0℃下加入单体并熟化3d.用IR、1HNMR、DSC及TGA对最终产物的结构与性能进行了表征.     

聚醚大单体溶液pH对减水剂性能的影响

以甲基烯丙醇聚氧乙烯醚和丙烯酸为主要原料,对聚醚单体溶液(底料)pH进行调控合成聚羧酸减水剂。通过测定聚醚转化率及减水剂相对分子质量及其分布以及评价减水剂的应用性能,确定了聚醚大单体溶液pH变化范围以及不同酸种类对减水剂性能的影响。结果显示,通过控制底料pH提高了聚醚大单体转化率,并且当底料pH控制为3时其转化率最高,由未调控pH的87.41%提升至pH为3时的95.43%,此时合成减水剂的分子量分布指数较小,由未调控pH时的3.183降至2.884;采用硫酸控制底料pH时,溶液中存在的硫酸盐为硫酸钠,其快速溶解减少了聚羧酸减水剂被水泥水化产物的包裹和消耗,更有利于提高聚羧酸减水剂分散性能。结果表明,通过控制聚醚大单体溶液pH的方式,在不改变减水剂合成工艺操作的前提下也可提升聚羧酸系减水剂的整体性能。     

负载钛催化体系催化合成低相对分子质量聚丁烯-1

以氢气为相对分子质量调节剂,采用自制的TiCl4/MgCl2-Al（i-Bu）3负载钛催化体系,合成了聚丁烯-1热塑性弹性体（PBt-TPE）。在3L釜中考察了Al/Ti、Ti/Bt、氢气压力及聚合温度对单体转化率、相对分子质量、乙醚中不溶物含量及结晶度的影响。结果表明：氢气压力能够有效调节聚合物的相对分子质量,随聚合温度的升高,聚合物转化率和相对分子质量先升高后降低;乙醚中不溶物含量呈降低趋势。     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

基于ATRP法制备的触角状亲水性羟胺树脂的吸硼性能的研究

以大分子引发剂氯乙酰化聚苯乙烯微球(PS-acyl-Cl)经原子转移自由基聚合(ATRP)法引发丙烯酰胺(AM)和甲基丙烯酸缩水甘油酯(GMA)单体的共聚接枝,制得一种触角状亲水性环氧载体(PS-acyl-g-P(AM-co-GMA)),再经二乙醇胺(DEA)的环氧基开环胺化反应,得到一种含多个-NCH2CH2OH螯合配基的多齿-五元螯合环的触角状亲水性羟胺树脂(PS-acyl-g-P(AM-co-GMA)-DEA)。将此树脂用于硼吸附研究,结果表明,PS-acyl-g-P(AM-co-GMA)-DEA树脂对硼的吸附满足Langmuir方程,为单分子层吸附;饱和吸附量约为37.7 mg·g-1,且树脂5 min即可达到吸附平衡,与其它已报道的吸硼树脂相比,该树脂具有更高的吸附量和吸硼速率。吸附动力学研究表明,树脂吸附硼的过程主要由颗粒扩散过程控制。重复使用5次后该树脂的吸附量基本不变,解吸率均在90%以上,重复使用性能良好。