双端氨基(聚)酰胺酸扩链的聚氨酯弹性体的合成、结构和性能

合成了3种不同相对分子质量的双端氨基(聚)酰胺酸,且以此和3,3′-二氯-4,4′-二氨基-二苯基甲烷(MOCA)为扩链剂,分别制备了聚氨酯弹性体,并对该系列进行了表征,研究了其性能和微相分离情况。结果表明,以(聚)酰胺酸为扩链剂合成的聚氨酯弹性体具有明显的微相分离结构,并具有较好的耐热性和机械性能。     

扩链剂对IPDI基透明聚氨酯弹性体的影响

采用异佛尔酮二异氰酸酯(IPDI)和不同结构的扩链剂、多元醇合成了透明聚氨酯弹性体，通过DSC、TG、WAXD等研究了聚氨酯弹性体的形态结构和力学性能、热稳定性及光学透明性。结果表明，扩链剂结构对聚氨酯弹性体形态结构和力学性能、热稳定性及光学透明性有很大影响。降低扩链剂长度有利于微晶的长大、微相分离程度及力学性能的提高；增加扩链剂用量，聚氨酯弹性体的微相分离程度、微晶尺寸、力学性能及热稳定性能提高；硬段含量对聚氨酯弹性体光学透明性的影响不明显。     

二醇扩链剂的性质对聚氨酯结构和性能的影响

氨基基甲酸酯弹性体的性能与许多因素有关,如原料组成的结构,其中包括二醇扩链剂扩链剂的结构因素。以二烯类二元醇齐聚物(软段)为基料用一步合成法制备聚氨酯时,我们采用4-腈基-1.2-环已烷二醇(4-H)代替1.4丁二醇(BB)作为扩链剂,能极大提高弹性体的强度,并保持较高的变形性能(表1)。     

MDI-50型聚氨酯弹性体的合成及性能

以聚醚多元醇和MDI-50为原料,采用预聚物法合成预聚体,再和扩链剂MOCA进行扩链合成聚氨酯弹性体。研究了预聚体中不同异氰酸酯基(-NCO)质量分数对MDI-50型聚氨酯弹性体性能的影响。采用差示扫描量热分析(DSC)、热重分析(TG)、红外光谱(FTIR)及力学性能等测试方法对聚氨酯弹性体的结构与性能进行了表征和分...     

M-CDEA在聚氨酯弹性体中的应用研究

分别以聚ε-己内酯多元醇(PCL)、聚四氢呋喃醚二元醇(55PTMG)和甲苯二异氰酸酯(TDI)为原料合成聚氨酯预聚体,分别用M-CDEA[4,4′-亚甲基-双-(3-氯-2,6-二乙二基苯胺)]和3,3’-二氯-4,4’-二氨基二苯基甲烷(MOCA)作为扩链剂合成聚氨酯弹性体,比较了两种不同扩链剂对聚氨酯弹性体的力学性能和耐热性能的影响。实验结果表明:与MOCA相比,由M-CDEA扩链的聚氨酯弹性体的硬度、撕裂强度、回弹和耐磨性较高。DSC和TG测试结果表明:经M-CDEA扩链的聚氨酯弹性体的耐热性能优于MOCA。     

聚氨酯脲微相分离程度及性能研究

以端羟基聚丁二烯丙烯腈(HTBN)和聚醚多元醇(N210)为软段,以甲苯二异氰酸酯(TDI)和异佛尔酮二异氰酸酯(IPDI)以及4,4′-二氨基-3,3′-二氯二苯甲烷(MOCA)和二甲硫基二胺基甲苯(DMTDA)为硬段,制备了一系列聚氨酯脲(PUU)弹性体。采用傅里叶变换红外光谱分析(FT-IR)、热重分析(TGA)、动态黏弹(DMA)、材料拉伸测试机等测试手段对合成的PUU进行了结构与性能表征,研究了聚氨酯体系中各组分对弹性体微相分离程度及各种性能的影响。结果表明,对称性较高且分子结构中含有刚性苯环的扩链剂和异氰酸酯有利于微相分离程度的提高。     

浇注型聚氨酯弹性体的研制

采用2,4-甲苯二异氰酸酯(TDI)、聚醚多元醇或聚酯多元醇、扩链剂等原料通过预聚物法合成了浇注型聚氨酯(PUR)弹性体,分析了柔性链段的分子结构、扩链剂的分子结构及异氰酸酯基的含量等因素对PUR弹性体力学性能的影响。结果表明,以聚己二酸丁二酯为柔性链段、MOCA或TX-2为扩链剂、异氰酸酯基质量分数为5％．5．5％时,所得PUR弹性体具有较好的综合性能。     

室温固化型MDI体系聚氨酯弹性体力学性能的研究

以不同结构多元醇和4,4′-二苯基甲烷二异氰酸酯(MDI-100)合成预聚体,再与不同扩链剂反应制备室温固化MDI型聚氨酯弹性体。讨论了多元醇种类、扩链剂种类、扩链系数、稀释剂用量、催化剂种类对聚氨酯弹性体力学性能的影响。结果表明,结构规整的多元醇制备的聚氨酯弹性体综合性能较好;二醇类扩链剂1,4-丁二醇(1,4-BDO)和对苯二酚二羟基乙基醚(HQEE)制备的弹性体性能较好,操作工艺可行;扩链系数以0.85~1.0为宜;适宜稀释剂质量分数为5%~10%;MDI室温固化体系的催化剂可选用HDcat。     

扩链剂对PPG-1000/MDI体系聚氨酯弹性体阻尼性能的影响

以聚氧化丙烯二醇(PPG-1000)、MDI-50与不同的二醇扩链剂采用二步法合成PPG-1000/MDI体系的聚氨酯(PU)弹性体,并对其阻尼性能进行了测试。结果表明,扩链剂对PPG-1000/MDI体系的聚氨酯弹性体的阻尼性能有明显影响。加入含侧甲基和醚键的扩链剂在不同程度上提高了聚氨酯弹性体的阻尼因子(tanδ),拓宽其阻尼温域。因此选择适宜的扩链剂对调节聚氨酯弹性体的阻尼温域具有一定的意义。     

2,4-二氨基甲酸乙酯甲苯对聚氨酯弹性体微相分离的影响

合成了一种分子结构中含有氨基甲酸酯基的化合物——2,4-二氨基甲酸乙酯甲苯,并加至聚氨酯弹性体中,采用傅里叶变换红外光谱(FTIR)、差示扫描量热分析(DSC)以及扫描电镜(SEM)等表征手段研究了该化合物对聚氨酯弹性体微相分离结构的影响。结果表明:加入2,4-二氨基甲酸乙酯甲苯后,聚氨酯弹性体的各基团之间形成了更多的氢键,提高了软段的玻璃化转变温度;另外当2,4-二氨基甲酸乙酯甲苯的添加达到一定量时,会促使弹性体硬段聚集形成微区。     

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.     

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。