减震降噪用聚氨酯弹性体材料的性能

在预聚中间体组分为聚四氢呋喃醚二醇(PTMG)/4,4’-二苯基甲烷二异氰酸酯(其NCO的质量分数为15％～ 20％)、扩链剂组分为PTMG/1,4-丁二醇(BDO)的条件下,采用半预聚体法,通过调节PTMG/BDO的平均分子量,合成出一系列邵尔A硬度为60～ 85的聚醚型聚氨酯弹性体,对其力学性能、耐水性以及动态力学性能进行了研究,并与同硬度的橡胶材料进行了比较.结果表明,随着PTMG/BDO平均分子量的逐渐减小,聚氨酯弹性体的邵尔A硬度、拉伸强度、定伸应力和撕裂强度逐渐提高,扯断伸长率逐渐降低,回弹性变化较小.所合成的聚氨酯弹性体使用的频率范围较橡胶材料宽,随频率变化的动态力学性能优于橡胶,且具有很好的耐水性.在频率为0.1～100.0 Hz时,无论是拉伸模式还是压缩模式,邵尔A硬度为70 ～80的聚氨酯弹性体均表现出很好的动态力学性能;在拉伸温度为35-160℃时,邵尔A硬度为70～85的聚氨酯弹性体动态力学性能好,使用温度范围较宽.     

浇注型聚氨酯弹性体与金属粘接性能的研究

以CPUE(浇注型聚氨酯弹性体)和45#钢为试验对象,探讨了胶粘剂种类、金属表面处理、聚氨酯(PU)硬度、加热时间和保存时间对CPUE/金属胶接件粘接性能的影响。研究结果表明:在5种胶粘剂中,双组分胶粘剂245N的粘接强度相对最高,而胶粘剂240N的耐水性相对最好;聚酯型CPUE/金属胶接件的粘接强度高于聚醚型CPUE/金属胶接件,高硬度CPUE/金属胶接件的粘接强度高于低硬度CPUE/金属胶接件;胶粘剂的粘接强度随加热时间延长而逐渐降低,CPUE/金属胶接件的保存时间为7 d时,粘接强度仍相对较高。     

HTBN/PTMG双软段聚氨酯弹性体的制备及力学性能研究

以甲苯二异氰酸酯(TDI)、端羟基聚丁二烯-丙烯腈共聚物(HTBN)、聚四氢呋喃醚二醇(PTMG)为主要原料,3,5-二甲硫基甲苯二胺(DMTDA)为扩连剂,采用浇铸法制备了聚氨酯弹性体。研究了聚氨酯预聚体中NCO含量、HTBN/PTMG质量比、PTMG相对分子质量和改变扩链剂用量以及热处理时间对聚氨酯弹性体力学性能的影响。结果表明,低相对分子质量PTMG和高热处理温度有利于提高聚氨酯弹性体的力学性能,当聚氨酯预聚体中HTBN/PTMG的质量比为50∶50、NCO质量分数为5.98%、NCO/NH2摩尔比为1.20、115℃下热处理2 h时,聚氨酯弹性体的力学性能最佳。     

扩链剂对PTMG体系CPUE的力学性能及耐溶剂性能的影响

采用聚四氢呋喃多元醇2000(PTMG 2000)、甲苯二异氰酸酯(TDI)合成了NCO封端的预聚体,然后分别采用4,4’-亚甲基-双(3-氯-2,6-二乙基苯胺)(MCDEA),3,3’-二氯-4,4’-二氨基二苯基甲烷(MOCA)以及2,4-二胺基-3,5-二甲硫基甲苯(E-300)进行扩链,并对制得的浇注型聚氨酯弹性体(CPUE)试片进行力学性能和耐溶剂性能的测定,分析并探讨了扩链剂种类对CPUE力学性能和耐溶剂性能的影响,为浇注型聚氨酯弹性体在胶辊、胶轮的应用推广提供参考。     

PTMG/PPG基CPU的相分离及力学性能研究

分别以聚四氢呋喃二醇(PTMG)、聚氧化丙烯二醇(PPG)及两者共混物(PTMG/PPG)作为软段,以2,4-甲苯二异氰酸酯(TDI)和扩链剂3,3'-二氯-4,4'-二氨基二苯甲烷(MOCA)作为硬段,采用预聚体法,制备了5种不同PTMG/PPG配比的浇注型聚氨酯弹性体(CPU)。研究了PTMG/PPG不同的配比对CPU的力学性能和微观相分离的影响。结果表明,纯PTMG型聚氨酯力学性能优于纯PPG型聚氨酯性能,随着PPG在混合聚醚多元醇的比例增加,所形成的CPU的力学性能出现一定程度的下降。纯PTMG型聚氨酯的玻璃化转变温度(Tg)低于纯PPG型聚氨酯的Tg,随着PPG在混合聚醚中的配比增加,所合成相应的聚氨酯弹性体的Tg移向高温区,微观相分离程度减小。     

新型PTMG-PO共聚醚聚氨酯弹性体的制备与性能研究

以一种新型聚四亚甲基醚二醇一环氧丙烷（PTMG—PO）共聚醚为原料,制备了浇注型聚氨酯（PU）弹性体,与不同软段的产品进行了分析比较。结果表明,提高预聚体NCO基含量,PTMG—PO聚氨酯弹性体的硬度和强度增加,伸长率下降。提高PTMG—PO相对分子质量,硬度升高,而拉伸强度降低。PTMG-PO弹性体的力学性能优于THF—PO性能。红外分析表明,PTMG—PO和THF—PO共聚醚结构单元基本相同;热分析结果显示,高相对分子质量的PTMG—PO弹性体的玻璃化转变温度低。耐热性差。     

NDI型聚氨酯弹性体宏观性能的研究

采用预聚物法合成了以聚四氢呋喃醚二醇(PTMG)、1, 5萘二异氰酸酯(NDI)、1,4丁二醇(BDO)、三羟甲基丙烷(TMP)等为主要原料的双组分浇注型聚氨酯弹性体。通过差示扫描量热分析、动态力学性能分析和常规力学性能分析,对NDI型聚氨酯弹性体的性能进行了研究。结果表明,NDI型聚氨酯弹性体有良好的低温柔顺性,动态生热低、储能模量高、力学性能优异;随着预聚物中NCO基含量的增加,软段玻璃化转变温度依次降低,平台区储能模量依次上升,损耗因子逐渐降低,拉伸强度先增大后减小,硬度逐渐升高。     

端羟基聚丁二烯／聚醚型聚氨酯弹性体的合成与性能

将端羟基聚丁二烯(HTPB)、聚四氢呋喃(PTMG)、二苯甲烷二异氰酸酯和1,4-丁二醇反应制备了聚氨酯弹性体。研究了多元醇质量比、制备方法对弹性体力学性能的影响。实验数据表明,各种方法制备出的聚氨酯弹性体的拉伸和撕裂性能均随HTPB／PTMG质量比增高直线下降。随HTPB／PTMG质量比加大,预聚体法制备的聚氨酯弹性体的力学性能的下降幅度小于改进的一步法,改进的一步法小于原一步法。动态力学性能测试研究表明,HTPB／PTMG质量比的提高使聚氨酯弹性体动态内生热依次降低,微相分离程度减弱。     

聚醚/聚酯型热塑性聚氨酯弹性体的合成研究

以聚四甲撑醚二元醇(PTMG)、已二酸丁二醇聚酯二元醇(PBA)、4,4’-二苯基甲烷二异氰酸酯(MDI)、和1,4-丁二醇(BDO)为原料,采用一步法合成聚醚/聚酯型热塑性聚氨酯弹性体(TPU)。研究原料配比对其力学性能和熔体流动速率的影响。结果表明:随PTMG质量分子量的增加,TPU的硬度和拉伸强度减小而断裂伸长率增加;随-NCO/-OH摩尔质量比的增加,TPU的拉伸强度增加、断裂伸长率减小,熔体流动速率减小;随PBA/PTMG摩尔比的增加,TPU拉伸强度和断裂伸长率先增大后减小。     

软段组成对MDI型聚氨酯弹性体性能的影响

采用半预聚体法,分别以聚四氢呋喃二醇(PTMG)、聚己内酯二醇(PCL)和聚己二酸新戊二醇酯二醇(PNA)为软段,液化MDI、1,4-丁二醇(BDO)为硬段制备具有不同软段组成的聚氨酯弹性体,研究了软段组成对聚氨酯弹性体性能的影响。结果表明,PCL型和PNA型聚氨酯弹性体力学性能较好,玻璃化转变温度较高,接触角较大,吸水率较低;浸水7 d后,PTMG型聚氨酯弹性体强度保持率较高。     

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.     

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.     

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。     

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.     

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.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Some Large Wood-Boring Beetles in Southeastern USA

Ethanol and α-pinene were tested as attractants for large wood-boring pine beetles in Alabama, Florida, Georgia, North Carolina, and South Carolina in 2002–2004. Multiple-funnel traps baited with (−)-α-pinene (released at about 2 g/d at 25–28°C) were attractive to the following Cerambycidae: Acanthocinus nodosus, A. obsoletus, Arhopalus rusticus nubilus, Asemum striatum, Monochamus titillator, Prionus pocularis, Xylotrechus integer, and X. sagittatus sagittatus. Buprestis lineata (Buprestidae), Alaus myops (Elateridae), and Hylobius pales and Pachylobius picivorus (Curculionidae) were also attracted to traps baited with (−)-α-pinene. In many locations, ethanol synergized attraction of the cerambycids Acanthocinus nodosus, A. obsoletus, Arhopalus r. nubilus, Monochamus titillator, and Xylotrechus s. sagittatus (but not Asemum striatum, Prionus pocularis, or Xylotrechus integer) to traps baited with (−)-α-pinene. Similarly, attraction of Alaus myops, Hylobius pales, and Pachylobius picivorus (but not Buprestis lineata) to traps baited with (−)-α-pinene was synergized by ethanol. These results provide support for the use of traps baited with ethanol and (−)-α-pinene to detect and monitor common large wood-boring beetles from the southeastern region of the USA at ports-of-entry in other countries, as well as forested areas in the USA.