高性能水性UV固化聚氨酯的合成与性能研究

用环氧丙烯酸酯(EA)、羟基硅油合成了环氧/有机硅改性水性光固化聚氨酯乳液(WPU);研究了EA、羟基硅油、亲水扩链剂二羟甲基丁酸(DMBA)的用量,中和度和硅烷偶联剂的添加量对乳液和涂膜性能的影响。用红外光谱和接触角测量仪对树脂进行表征。结果表明:通过EA、羟基硅油改性的水性光固化聚氨酯涂膜的硬度高、附着力强、耐水性较好,克服了未改性水性光固化聚氨酯的缺点。当EA用量为4%、羟基硅油为2%、DMBA为8%、中和度为80%、硅烷偶联剂的添加量为1%时,水性光固化聚氨酯乳液的综合性能较好,树脂接触角大大提高。     

硅烷改性自交联水性聚氨酯的合成及其涂膜性能研究

以异佛尓酮二异氰酸酯(IPDI)、聚醚二元醇(PTMG)及二羟甲基丙酸(DMPA)为主要原料,合成了聚氨酯预聚体,并引入含酮羰基的双羟基化合物(DDP)与预聚体进行交联,再加入3-氨丙基三乙氧基硅烷(KH550)改性,合成了稳定的高交联度脂肪族水性聚氨酯。采用傅里叶变换红外光谱(FT-IR)和热质分析(TG)对水性聚氨酯的结构进行了表征,并对胶膜的耐介质性、热稳定性和机械性能进行了测试。结果表明:经KH550改性的WPU综合性能明显提高。当KH550含量由0增加到10%时,拉伸强度由20 MPa增加到27 MPa,断裂伸长率从330%降至198%,吸水率由43.2%降至21.3%,吸丙酮率亦由47.5%降至26.2%。FT-IR测试结果显示,KH550和DDP成功引入聚氨酯分子链上,实现了化学改性。TG分析表明,改性的水性聚氨酯耐热性明显提高。     

改性纳米氧化锌对水性聚氨酯乳液性能的影响

以无水乙醇为溶剂、正硅酸乙酯(TEOS)为包覆剂对纳米Zn O表面进行无机包覆,然后用硅烷偶联剂(KH-550)对其表面进行改性,将改性后的纳米Zn O(即Zn O/Si O2/KH550)对水性聚氨酯乳液进行改性,研究了改性纳米Zn O的用量对水性聚氨酯(WPU)乳液涂膜的吸水率、吸甲苯率和拉伸性能的影响,通过傅里叶变换红外光谱(FT-IR)、扫描电镜(SEM)和水接触角测试对纳米Zn O和WPU改性前后的结构及疏水性进行了表征。结果表明,改性后的纳米Zn O粒子团聚减少,疏水性提高。当改性纳米Zn O的添加量为聚氨酯中有机物质量的0.6%时,所制备的用改性纳米Zn O改性的WPU乳液涂膜性能较好,吸水率、吸甲苯率分别为20.35%和30.50%,低于未改性的WPU;拉伸强度达到13.45 MPa,水接触角较未改性WPU涂膜提高了25°。     

侧链含氟聚丁二烯型水性聚氨酯的制备及性能研究

在合成端羟基聚丁二烯(HTPB)型水性聚氨酯(WPU)的基础上,以甲基丙烯酸十二氟庚酯(DFMA)为共聚单体,采用无皂乳液聚合法制备了侧链含氟HTPB型水性聚氨酯(FHWPU),并采用透射电子显微镜(TEM)、X射线光电子能谱分析(XPS)及接触角测试仪等对其结构与性能进行了表征。结果表明,分散液颗粒具有明显的核壳结构;DFMA添加质量分数为20%时,FHWPU的成膜性和贮存稳定性最佳;DFMA改性后的WPU胶膜表面氟元素存在富集,高温处理有助于含氟链段向胶膜表面迁移,经140℃热处理后,与未改性WPU膜相比,其水接触角增大了42.2%,表面自由能下降了60.9%。     

聚酰胺-胺型树枝状水性聚氨酯的合成与表征

为了提高水性聚氨酯耐水性等性能,以异佛尔酮二异氰酸酯(IPDI)、聚四亚甲基醚二醇(PTMG)、二羟甲基丙酸(DMPA)、1,4-丁二醇(BDO)等为原料,二月桂酸二丁基锡(DBTDL)为催化剂,通过预聚体法合成了单端封闭的聚氨酯预聚体(PPU),然后以一代端羟基树枝状聚合物(PAMAM-OH)为核,通过接枝共聚法制备了树枝状水性聚氨酯(HWPU)。通过单因素分析法优化出PPU的最佳合成条件:反应时间为2 h,反应温度为80℃,n(NCO)∶n(OH)为6∶1。采用FIIR、XRD和纳米粒度表面电位分析仪对产物的结构和性能进行了表征,并对胶膜的耐水性、表面粗糙度和力学性能进行了测试。结果表明:HWPU乳液粒径为43.56 nm,胶膜结晶度为1.59%,胶膜24 h的吸水率为4.8%,拉伸强度为39.2 MPa,断裂伸长率为376.4%,胶膜表面粗糙度降低。与未加PAMAM-OH的水性聚氨酯(WPU)相比,HWPU的吸水率降低了67.1%,拉伸强度提高了74.2%,耐水性和拉伸强度得到明显提高。     

具有亲/疏水链端的混合封端型水性聚氨酯

以异佛尔酮二异氰酸酯(IPDI)、聚己二酸-1,4-丁二醇酯二醇(PBA2000)、2,2-二羟甲基丙酸(DMPA)合成聚氨酯预聚体(PPU),以部分封端的羟基硅油(MPSi)作为疏水封端剂,以与MPSi同等物质的量的氨基乙酸(Gly)作为亲水封端剂,合成具有亲/疏水链端的混合封端型水性聚氨酯(MEPU)。研究了r值〔n(IPDI)∶n(PBA2000)〕、DMPA用量(以IPDI和PBA2000的总质量为基准,下同)、MPSi用量(以PPU的总质量为基准,下同)对MEPU性能的影响。结果表明,当r=3.0、w(DMPA)=5%、w(MPSi)=15%时,MEPU乳液稳定透明,与未改性的水性聚氨酯相比,MEPU胶膜吸水率由16.7%减小到9.5%,水接触角由74.5°增加到92.6°,初始分解温度由264℃提高到293℃,拉伸强度提高了0.11MPa,断裂伸长率提高了5.81%。在不改变乳液稳定性的基础上,MEPU胶膜耐水性和耐热性明显提高。     

葫芦巴胶改性水性聚氨酯的制备及性能

以聚酯多元醇PE-3020、HDI(六亚甲基二异氰酸酯)、DMPA(2,2-二羟甲基丙酸)、FG(葫芦巴胶)等为主要原料,合成FG改性WUP(水性聚氨酯)乳液;考察了FG的加入量对乳液外观、粒径、耐水性、力学性能的影响。研究结果表明:当w(FG)=0.3%(相对于WPU质量而言)时,乳液外观呈现半透明泛蓝光,热稳定性高于未改性WPU,拉伸强度达到19.758 MPa,吸水率降低至13.88%,接触角77.5°。综合可知,FG改性的WPU乳液综合性能得到了显著提高。     

有机硅改性形状记忆水性聚氨酯的制备

将形状记忆水性聚氨酯用不同的硅烷偶联剂和端羟基硅油进行改性,并研究其改性前后的性能。结果表明:当硅烷偶联剂的质量分数为1%时,材料具有良好的力学性能、形状记忆性能和耐水性能;改性后,材料的形状固定率均为100%,形状回复率为96%以上;经硅烷偶联剂KH570改性的形状记忆水性聚氨酯的拉伸强度为49.96 MPa,较未改性体系提高了18.42%;端羟基硅油改性使材料质量损失50%的温度从370.21℃提高到378.13℃。     

琼胶寡糖的抗氧化活性研究

以琼胶寡糖为研究对象,测定琼胶寡糖中还原糖的含量、FRAP值、对DPPH自由基、羟基自由基(·OH)和超氧阴离子自由基(O_2~-·)的清除率,探究琼胶寡糖的总还原力和对三种自由基的清除活力。研究表明,浓度为20 mg/m L的琼胶寡糖样液对DPPH自由基清除率高达94. 43%;浓度为20 mg/m L的琼胶寡糖对羟基自由基清除率为25. 35%; 1 m L的10 mg/m L样液对NBT的超氧阴离子自由基的抗氧化活力为4. 49 u。此外还进一步研究其抗氧化能力和还原糖之间的关系,为琼胶寡糖的产业化提供理论基础。     

有机硅丙烯酸酯改性水性聚氨酯的合成与性能

以异佛尔酮二异氰酸酯(IPDI)、g-氨丙基三乙氧基硅烷(KH550)、甲基丙烯酸甲酯(MMA)、g-(甲基丙烯酰氧基)丙基三甲氧基硅烷(KH570)为原料,分别合成了水性聚氨酯预聚体(WPU)、聚丙烯酸酯(PA)、有机硅改性的水性聚氨酯预聚体(Si WPU)和有机硅改性的聚丙烯酸酯(Si PA),然后以WPU、SiWPU、PA、Si PA为原料,采用互穿网络聚合法合成了有机硅-丙烯酸酯双重改性水性聚氨酯。通过测定吸水率和水接触角考察了PA、Si PA、Si WPU含量对胶膜耐水性能的影响并分析了反应机理。结果表明:SiWPU-40%-SiPA-37.5%〔40%为Si WPU的含量(以WPU和SiWPU总质量为基准,下同);37.5%为Si PA占膜总质量百分数〕胶膜吸水率从改性前样品WPU的37.8%降低至改性后的6.8%,接触角从56.8°增至86.4°,铅笔硬度从改性前的2B提升至H。热重分析显示,T_(max)(样品热分解速率最大时的温度)从改性前的340.2℃提升至412.4℃;TEM表明,改性后的乳胶粒形成了核壳结构;XRD和断面SEM显示,PA和有机硅改性均增加了聚合物的交联度。     

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.     

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.     

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.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料，介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比，介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序，对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。     

Inorganic/organic nanocomposite coatings: The next step in coating performance

Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.