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1.
尿素改性苯酚-甲醛树脂胶粘剂的研究   总被引:5,自引:0,他引:5  
研究了由苯酚、甲醛和尿素为主要原料制备尿素-苯酚-甲醛(简写为UPF)树脂胶粘剂的配比及工艺条件。制得的胶粘剂的游离酚、游离醛含量低,水溶性、贮存性好,原料成本低,适用于浸渍作保温材料的矿物纤维。  相似文献   

2.
研究苯酚-甲醛树脂MK-95(简称MK-95)在轿车子午线轮胎胎体胶中的应用。结果表明:MK-95不含游离间苯二酚和其他添加剂,其软化点和挥发分含量低于间苯二酚-甲醛树脂;在胎体胶中以MK-95等量替代间苯二酚-甲醛树脂,胶料的硫化特性、物理性能、动态力学性能和粘合性能相当,成品轮胎的高速、耐久和路试性能均达到要求。  相似文献   

3.
为从根本上消除木材胶合制品的甲醛释放对环境和人体健康的危害及改善尿素-乙二醛(UG)树脂的性能,选择无毒、低挥发的乙二醛代替甲醛,与尿素、苯酚反应制备苯酚-尿素-乙二醛(PUG)共缩聚树脂木材胶黏剂。研究了在反应的不同阶段加入苯酚以及苯酚的加入量对树脂性能的影响,并通过傅里叶变换红外光谱法(FTIR)对树脂的结构进行了表征。结果表明:在所研究的合成条件下,PUG树脂的pH和状态受苯酚加入量和加入时间的影响不大,苯酚的加入量为尿素总量的10%为宜;树脂中主要含有氮氢(N—H)、氧氢(O—H)、羰基(C=O)、饱和碳氢(C—H)、醚键(C—O—C)及碳氮(C—N)键等主要官能团。  相似文献   

4.
以花生壳苯酚液化产物为原料,制备花生壳苯酚液化产物-尿素-甲醛(PLPUF)树脂胶黏剂。采用正交试验探讨了制备PLPUF树脂胶黏剂的最优配比,以提高其综合性能,结果表明:第一批尿素(U1)/第二批尿素(U2)物质的量比、液化产物(PL)/尿素(U)物质的量比以及液化产物和尿素总用量(PL+U)与甲醛(F)物质的量比为3:1、1:1.5和1:1是PLPUF树脂胶黏剂制备的最佳配比;此配比下胶合强度达到了0.83 MPa,含固体量为47.11%,游离甲醛的量为0.05%,以酚醛树脂胶黏剂为标准,PLPUF树脂胶黏剂能满足木材工业树脂的使用要求。PLPUF树脂在贮存过程中黏度逐渐上升,贮存5~15 d胶合强度为0.87~1.15 MPa,22 d后胶合强度降低至0.74 MPa,仍可满足使用条件。PLPUF树脂的FT-IR图中出现酰胺C=O和C—N等伸缩振动峰,表明尿素参与反应、改性树脂,而加入固化剂前后树脂的FT-IR吸收峰相同,结合DSC曲线表明固化剂的加入不改变树脂结构,但可以改善PLPUF树脂的固化过程,降低固化温度和固化反应热。  相似文献   

5.
本文研究了由苯酚,甲醛和尿素为主要原料制备尿素-苯酚-甲醛(简写为UPF)树脂胶粘剂的配比及工艺条件.制得的胶粘剂的游离酚、游离醛含量低.水溶性、贮存性好,原料成本低,适用于浸渍作保温材料的矿物纤维.  相似文献   

6.
在双酚A环氧树脂中加入不同的酚醛树脂进行改性。所用的酚醛树脂是由苯酚/甲醛(PN)和腰果酚/甲醛(CDN)缩合的酚醛清漆树脂(a),还有腰果酚-苯酚混合物与甲醛的缩合产物(CPNs)(b)。腰果酚是腰果壳液(CNSL)(一种可再生资源)的主要成份。制备酚醛清漆重量分数为2.5~20%的环氧树脂并测试其机械性能、吸水性能等。酚醛清漆重量分数为5~10%时,共混物的性能有了实质性的改善。随着酚醛清漆含量的增加,这些性质呈现下降趋势。酚醛清漆中,酚醛材料与甲醛的最佳化学计量比为1:0.8,此时的性能得到最大改善。在研究酚醛清漆过程中,制备的那些不同摩尔比率的腰果酚-苯酚共混物在断裂时会吸收较高的能量,这种性能会随着改性树脂中的腰果酚含量的增加而增加,直到其含量为40%。这些环氧-酚醛清漆共混物的性能特征暗示了酚醛清漆树脂的增韧作用,特别是苯酚-腰果酚-甲醛树脂。  相似文献   

7.
脲醛树脂胶粘剂研究进展   总被引:28,自引:3,他引:25  
陶绪泉  赵其昌 《粘接》1998,19(5):19-23
综述了脲醛树脂的国内研究情况,着重介绍了反应机理、耐水性能、游离甲醛含量、树脂稳定性、耐老化性能等,并提出了一些建议。  相似文献   

8.
苯酚改性脲醛树脂合成工艺及性能的研究   总被引:2,自引:3,他引:2  
用苯酚作为改性剂,采用高温(90℃)缩聚反应合成改性脲醛树脂胶粘剂,改进了合成工艺,缩短了反应时间。通过引入苯环改善了耐水、耐老化性能。分析了各因素对改性脲醛树脂的影响,得到甲醛、尿素、苯酚摩尔比为10:8:1时树脂性能最佳,胶合强度和木破率均达到GB/T 17656-1999标准规定值。  相似文献   

9.
树脂补强体系下的橡胶硫化实际上是树脂网络和橡胶网络的形成以及相互穿插的过程,热塑性苯酚甲醛树脂的分子量以及游离酚含量势必会对树脂网络的形成产生影响,从而影响橡胶的硫化以及胶料的加工过程。本文就是制备出不同分子量的热塑性苯酚甲醛树脂以及不同游离酚含量的热塑性苯酚甲醛树脂,测试含有这些树脂胶料的加工性能,得出结论,并且用这些结论分析市售的热塑性苯酚甲醛树脂对胶料加工性能的影响。  相似文献   

10.
尿素—苯酚—甲醛树脂胶粘剂的研制   总被引:3,自引:0,他引:3  
申迎华  王九芬 《化学与粘合》1995,(3):130-133,156
本文研究了由苯酚、甲醛和尿素为主要原料制备尿素-苯酚-甲醛(简写为UPF)树脂胶粘剂的配比及工艺条件。制得的胶粘剂的游离酚、游离醛含量低,水溶性、贮存性好,原料成本低,适用于浸渍作保温材料的矿物纤维。  相似文献   

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12.
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.  相似文献   

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14.
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.  相似文献   

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17.
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.  相似文献   

18.
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.  相似文献   

19.
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.  相似文献   

20.
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。  相似文献   

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