纯净水瓶盖专用树脂HDPE 5603JP的开发

采用了BCE催化剂,利用小试装置考察了氢气和1-丁烯对该催化剂催化乙烯聚合的影响。并将该催化剂用在淤浆法聚乙烯生产装置上,生产了纯净水瓶盖专用高密度聚乙烯(HDPE)5603JP。测试结果表明,该树脂具有适宜的密度、熔体流动速率、力学性能和卫生性能,适合生产瓶盖。生产的瓶盖产品各项性能也与国外原料生产的瓶盖产品相当。     

HDPE埋地排水管专用树脂的工业开发

根据国家标准、欧洲标准中对高密度聚乙烯(HDPE)埋地排水管材专用树脂的要求,确定了产品的质量控制指标和生产工艺参数。在HDPE淤浆法工艺生产装置上,开发了具有优良的物理性能、加工性能和耐环境应力开裂(ESCR)性能的埋地排水管材专用树脂6360M。6360M屈服拉伸强度大于25 MPa;弯曲模量大于1200MPa;ESCR(F50)在1000 h以上;通过了耐内压性能测试。     

HDPE管材专用树脂的开发

研究了高密度聚乙烯(HDPE)树脂的反应工艺条件与产品物性的对应关系,通过分析反应压力、反应温度、共聚单体和停留时间对产品性能的影响,确定了生产HDPE管材专用料YEM4803T的工艺参数,工业化生产了YEM4803T产品,对该产品进行了物性测试和加工应用试验。结果表明,YEM4803T加工流动性能和物理性能优良。     

果酒包装内盖专用LDPE的开发

根据注塑瓶盖制品性能和对产品加工的要求,结合管式法低密度聚乙烯生产装置的工艺特点,确定了果酒包装内盖专用低密度聚乙烯树脂LD607BW的基本物性指标:密度为(0.921±0.002)g/cm3,熔体流动速率为(7.5±1.0)g/10 min,拉伸断裂应力≥8 MPa,断裂标称应变≥80%。根据基本物性指标确定了试生产工艺条件,包括聚合温度、聚合压力和对助剂的要求等。通过提高反应器尾端第四、第五反应区的温度,降低反应压力,使长链支化、短链支化增多,降低了产品的密度和硬度,解决了制品的翘曲问题。产品性能测试及应用表明,工业化试生产的LD607BW满足指标要求且质量稳定。     

保鲜瓶盖专用LLDPE树脂的开发

通过改善催化剂配方及优化调整工艺参数,解决了生产中出现的催化剂活性低、粉料细化发黏、流动性差等问题,成功地开发了宽口保鲜瓶盖专用线型低密度聚乙烯树脂DNDA-2020。该树脂的熔体流动速率为15.0~30.0 g/10 min,密度为≤0.922 g/cm3,拉伸断裂强度为7.0.~7.50 MPa,拉伸屈服强度为10.0~11.0 MPa。用DNDA-2020制备的宽口瓶盖的光泽度、柔韧性、密封性及加工性能均满足用户要求。     

单向拉伸PVC膜专用树脂的开发与加工应用(二)

通过试验确定了单向拉伸PVC膜(SOPVC膜)专用树脂的性能指标:平均聚合度在1 000左右,老化白度≥82％,分子质量分布指数≤2,增塑剂吸收量≥24 g.开发了 SOPVC膜的生产工艺和配方,在工业化PVC装置上成功生产出了 SOPVC膜专用树脂,并进行了工业化加工应用试验.结果表明:笔者开发的SOPVC膜专用树脂能够满足工业化加工生产要求,制得的SOPVC膜的性能好于国产SG5型PVC树脂,与进口的SOPVC膜专用树脂相当.     

LDPE 高透明专用树脂的开发

探讨了高透明低密度聚乙烯(LDPE)专用树脂25E的生产工艺条件,分析了反应压力、反应温度、相对分子质量调节剂及引发剂的用量对高透明LDPE树脂性能的影响,最终确定了反应温度为(315±5)℃、反应压力为(255±5)MPa、调节剂丙醛注入量为20~30kg/h等生产工艺参数,并对产品进行了基础物性和加工性能分析。加工应用试验表明,25E产品的综合性能优良,达到了国内同类产品的先进水平。     

CPE专用高密度聚乙烯树脂的开发

通过工艺条件的优化和催化剂的选型,在淤浆法聚乙烯装置上开发了氯化聚乙烯(CPE)专用高密度聚乙烯(HDPE)树脂。该CPE专用HDPE树脂与同类树脂的相对分子质量及其分布相当,密度介于国产树脂A和进口树脂B之间;结晶温度接近进口树脂A,但熔融温度及热焓较进口树脂A略高;熔体流动速率和堆密度与进口树脂A相差不大;大颗粒及细粉含量都少于进口树脂,且粒径分布更集中;孔径、孔容以及比表面积与进口树脂A接近。采用该CPE专用HDPE树脂生产的制品各项性能均达到了指标要求。     

高强度薄膜专用HDPE的生产

在全密度聚乙烯装置上采用Unipol气相法工艺,以1-丁烯为共聚单体生产高强度薄膜专用高密度聚乙烯(HDPE)DGDB6097。DGDB6097的熔体流动速率(负荷21.6 kg)为7.00~13.00 g/10 min,密度为0.945~0.951g/cm3,拉伸屈服应力大于或等于19 MPa,拉伸断裂应力大于或等于23 MPa,断裂标称应变大于或等于500%。与相同工艺生产的普通薄膜专用线型低密度聚乙烯相比,DGDB6097的密度高、拉伸强度大;与国内市场常见的高强度薄膜专用HDPE DGDA6098相比,DGDB6097的力学性能、结晶性能、相对分子质量及其分布以及其薄膜的各项性能相当。加工应用表明,DGDB6097的加工性能和薄膜力学性能均满足用户要求。     

台塑公司高密度聚乙烯专用树脂的开发策略

介绍了台湾塑胶工业股份有限公司高密度聚乙烯(HDPE)树脂的生产装置、工艺技术、生产能力、树脂牌号及新产品开发现状,同时阐述了HDPE专用树脂的开发策略。目前,台塑公司HDPE商品牌号台塑烯的产品包括薄膜专用树脂、中空吹塑专用树脂、挤出专用树脂和注塑等用树脂等,并且产品具有单峰、双峰甚至宽峰相对分子质量分布的特性。2006年,台塑公司将调整台塑烯专用树脂的生产比例,强化产品结构而维持一定的营利水平。     

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.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

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。