高邻位热塑性酚醛树脂的合成

讨论了催化剂,苯酚与甲醛的摩尔比,反应时间等诸因素的影响。研究了高邻位热塑性酚醛树脂的合成工艺。     

有机硅改性热塑性酚醛树脂制备的研究

以苯酚和甲醛为原料。采用草酸作为催化剂,通过有机硅改性合成的热塑性酚醛树脂。讨论了催化剂草酸的含量、反应时间和有机硅的含量对改性酚醛树脂性能的影响。结果表明：当草酸含量为2．0,wt%,反应时间为2．5h,有机硅含量为3．0wt％时,合成改性酚醛树脂的固化时间、流动距离和挥发度等综合性能较好,合成的酚醛树脂可用作摩擦材料粘合剂。     

高物质的量比低游离酚热塑性酚醛树脂的合成工艺

为降低耐火材料用酚醛树脂中游离酚的含量,选择苯酚与甲醛物质的量比1∶1.5,分步加入甲醛,醋酸锌为催化剂,添加质量分数2%,糠醇为溶剂,在60～85℃下制备了液态热塑性酚醛树脂,对产品的物化性能进行了测试并以红外光谱对其结构作了表征。结果表明,该工艺合成的酚醛树脂存在高邻位取代结构,残炭量达到45.66%,游离酚质量分数为1.87%。以原料中苯酚的量计算,产率可达到148.8%。     

苯酚-亚联苯型酚醛树脂的合成与表征

以苯酚及4,4′-二（氯甲基）联苯为单体,盐酸作催化剂经Friedel-Crafts烷基化反应,合成了苯酚-亚联苯型酚醛树脂。利用傅里叶红外光谱（FTIR）、核磁共振（1H NMR、13C NMR）、凝胶渗透色谱（GPC）与热失重分析（TGA）对产物的结构、分子量、分子量分布及耐热性进行了表征与测定。结果表明：经Friedel-Crafts烷基化反应所得到的苯酚-亚联苯型酚醛树脂系邻、对位取代的混合物。随着苯酚用量的增大,苯酚-亚联苯型酚醛树脂的相对分子量逐渐减小,分子量分布逐渐变窄。产物耐热性能优异,起始分解温度能达到340℃。     

合成条件对氨催化酚醛树脂结构的影响

利用红外光谱分析研究了反应温度、时间、催化剂用量,原料配比对合成的氨催化酚醛树脂中的羟甲基含量、邻对位取代比例、醚键含量和残炭率的影响。结果表明,合成条件不同,酚醛树脂中各特征基团含量变化明显,其中,邻对位取代比例变化较大,当氨水用量为4%时,邻、对位取代比值达到1.56。控制反应温度90℃,反应时间130~150 min,催化剂氨的用量3%~4%,甲醛、苯酚物质的量比为1.25时,树脂残炭率可达到49%左右。     

对甲苯磺酸催化合成2，2-双（3-苯基-4-羟基苯基）丙烷研究

以主催化剂对甲苯磺酸及助催化剂巯基丙磺酸来催化丙酮和邻苯基苯酚,经过缩合反应合成了2,2-双（3-苯基-4-羟基苯基）丙烷（双OPP-A）,实验过程中研究了原料配比、反应温度、催化剂用量、反应时间等因素对产物的影响,得到合成2,2-双（3-苯基-4-羟基苯基）丙烷的最优工艺条件为：丙酮、邻苯基苯酚、对甲苯磺酸和巯基丙磺酸物质的量比为1：4：O．25：O．25,最佳反应时间为7h、最佳反应温度为60℃,2,2-双（3-苯基-4-羟基苯基）丙烷收率达到74．2％,经重结晶纯度达99．5％。通过红外光谱、核磁共振和熔点等分析手段对产物结构进行了确证。     

2-氯-6-三氯甲基吡啶的制备研究

采用等质量混合的三乙醇胺与过氧化苯甲酰作为催化剂。在管式反应器中2-甲基吡啶盐酸盐（MPCH）与氯气反应合成了2-氯-6-三氯甲基吡啶（NP）,研究了催化剂用量、反应原料、原料配比、加料速率和反应温度对氯化产物中NP含量及制备过程收率的影响。优化反应条件为：采用MPCH作原料,m（催化剂）：m（2-甲基吡啶）=0．01：1,N（C12）：N（MPCH）=6：1,反应温度为180～190℃,MPCH和氯气的较佳进料速率分别为15g／h和49．4g／h,此时氯化产物中NP的含量可达78．5％,制备过程收率达93．4％。氯化反应NP选择性高。工艺简单,易于实现工业化。     

邻甲酚、间甲酚的常压合成研究

以二甲苯为溶剂,邻氯甲苯、氢氧化铯为原料常压条件下合成邻甲酚和间甲酚。其优化工艺为投料比n（氢氧化铯）：n（邻氯甲苯）=1．8：1．18-冠-6为相转移催化剂,回流反应8h,此工艺条件下产品的总收率可达64％,生成的间甲酚和邻甲酚的比例为1．2：1,无副产物。     

高邻位邻甲酚醛树脂的制备及表征

邻甲酚醛树脂制备工艺稳定，加工简单，但随着对邻甲酚醛树脂研究的越发深入，更高性能的高邻位邻甲酚醛树脂被开发应用，其优点为制品成型快固化速度快。但现阶段对其的研究较少且不全面。研究了采用醋酸锌与草酸组合的双催化剂制备高邻位邻甲酚醛树脂的方法，对反应过程中醛酚比、催化剂的用量、反应时间、反应温度等条件进行响应面分析，得到最优的高邻位邻甲酚醛树脂制备条件，并用红外及核磁仪器表征了树脂结构，测定了树脂的软化点与邻位率。最终成功制备了软化点85℃、邻位率87%的高邻位邻甲酚醛树脂。     

一氯甲苯异构体的分离

邻位和对位氯甲苯异构体在有机合成工艺中已引起人们的注意。在一氯甲苯的制备中,异构体的组成与所用的催化剂有关(催化剂为金属铝、铁、锆、钛、锡、碘、铊、钒的氯化物),其异构体组成如下:邻位50～70%,对位30～50%,间位0.5～1.0%。反应物中若有硫或它的衍生物(一氯化硫或二氯化硫)存在时,对位异构体含量按邻位异构体含量有所增     

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。