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1.
CR/MMA-AA自交联型接枝共聚物的合成与粘接性能研究   总被引:5,自引:2,他引:3  
在交联单体N-羟甲基丙烯酰胺(N-MAA)存在下,研究了氯丁橡胶(CR)/甲基丙烯酸甲酯(MMA)-丙烯酸(AA)三元接枝共聚及产物性能,结果表明,在引发剂 为1.6 ̄2.0%,N-MAA用量为2.2 ̄2.6%,AA(AA+MMA)(质量比)为14%,反应时间为5h,反应温度为80 ̄85℃时,产物的性能较优。对产物还进行了红外光谱表征和粘接性能测试。  相似文献   

2.
自交联型SBS接枝共聚物的合成与粘接性能研究*   总被引:3,自引:0,他引:3       下载免费PDF全文
研究了在混合溶剂中了二烯-苯乙烯嵌段共聚物(SBS)与丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)及交联单体N-羟甲基丙烯酸胺(N-MAA)进行四元接枝共聚的反应条件及其产物的粘接性能。讨论了引发剂浓度、交联单体用量、单体配比、反应时间及反应温度对接枝共聚物的影响。实验确定的最佳反应条件为:引发剂BPO用量为SBS用量的1.8%—2.2%;交联单体N-MAA用量为SBS用量的16%—1.8%;BA/(BA+MMA)用量比为35%;反应时间为35—4.5h;反应温度为80—85℃。用红外光谱对接枝共聚物进行了分析鉴定。性能测试显示出该四元接枝共聚物对聚氯乙烯、SBS等难粘材料有较高的剥离强度。  相似文献   

3.
孙继杰 《橡胶工业》1996,43(7):412-416
含有活性添加剂的M-8_B1和M-8_T2K的两种油品对NBR-18O形密封圈有一定的副作用,通过调整NBR胶料硫化体系(硫黄0.3;促进剂CZ1.5;促进剂M0.5;硫化剂DCP2.0)和补强剂炭黑的用量(高耐磨炭黑55;喷雾炭黑40).可以使其满足抗两种油品侵蚀的性能要求。另外,在NBR胶料中添加25份耐寒增塑剂(邻苯二甲酸二丁酯10;癸二酸二辛酯15).可提高胶料的耐低温性能,并使脆性温度降至-65℃以下。  相似文献   

4.
对MNA-TBP从盐酸介质中萃取Ir(Ⅳ)作了研究.结果表明:MNA-TBP对Ir(Ⅳ)萃取有协同效应.当MNA和TBP在正辛烷中的浓度各为0.45mol/L,待萃液中HCl总浓度为4mol/L,铱浓度为173.13μg/ml,相比为1时,协萃系数R为2.33,协萃合物的组成为(MNAH)+.IrCl$2-6.(HTBP)+.  相似文献   

5.
本文研究了对甲基苯乙酸苄基酯(BCO2A)及苯乙酸1-萘基酯(ACO2N)在ZSM-5沸石中的光化学反应.研究发现,光解BCO2A在ZSM-5沸石中主要生成BA,而光解ACO2N只生成AA及NN.两种酯的产物分布和在乙腈溶液中的光解完全不同.这些结果是由ZSM-5沸石孔腔对底物分子的尺寸及形状具有选择性而引起的.  相似文献   

6.
金—钼酸盐—丁基罗丹明B体系显色反应研究   总被引:4,自引:0,他引:4  
研究了在高氯酸和聚乙烯醇(PVA)存在下,金与钼酸盐和丁基罗丹明B(BRB)的显色反应。其适宜条件CHClO4=1.5mol/L,CMoO2-4=9.1×10-4mol/L,CBRB=3.8×10-5mol/L及0.08%PVA。金钼杂多酸—丁基罗丹明B离子缔合物的最大吸收位于570nm,表观摩尔吸光系数为3.36×106L·mol-1·cm-1,金量在0~40μg/L范围内服从比尔定律,测定极限(S/N=3)0.90μg/L(n=10),对于28μgAu(Ⅲ)/L测定的相对标准偏差2.1%(n=7)。缔合物至少可稳定5h,摩尔比Au∶BRB=1∶3。考察了44种共存离子的影响,大多数常见离子不干扰,用活性炭分离富集金,对砂矿和炭粉中金的测定,结果满意。  相似文献   

7.
吴石山  徐敏  王丽萍  邹惠芳 《橡胶工业》1996,43(12):730-732
轿车用O形密封胶料的生胶选择NBR2707/NBR3604(70/30)并用,硫化剂选择过氧化二异丙苯(2.5份),增塑剂选择液体NBR,防老剂选择防老剂MR/RD(1/1.5)并用,补强剂选择喷雾炭黑(60份)。胶料性能达到德国大众公司VW2.8.1-P70标准,产品可为大众公司系列轿车配套。  相似文献   

8.
甲基丙烯酸镁对NBR的补强作用   总被引:21,自引:7,他引:14       下载免费PDF全文
研究了在过氧化物硫化体系条件下,硫化剂DCP用量和甲基丙烯酸镁[Mg(MAA)2]用量对NBR硫化胶性能的影响,并考察了Mg(MAA)2对不同橡胶的补强作用。试验结果表明,Mg(MAA)2对NBR有明显的补强作用。随着Mg(MAA)2用量的增大,NBR硫化胶的拉伸强度和撕裂强度显著提高。在不加任何传统补强剂(如炭黑)的情况下,加入Mg(MAA)2可使NBR硫化胶的拉伸强度达到3020MPa,扯断伸长率达到544%。Mg(MAA)2对不同橡胶的补强效果与橡胶本身的极性等因素密切相关,补强NBR的效果最好,EPDM和SBR次之,BR最差  相似文献   

9.
在SBR中加入环化试剂AlEt2Cl-C6H5CH2Cl,在120℃,20min条件下制备了环化SBR,并借助IR,^1H-NMR,DSC,GPC等方法对产物性能进行了表征。结果表明,二国本溶剂参与了环化反应,且随环化度增加,参与反应的二甲苯量也逐渐增加,并确定了环结构的形成。利用^1H-NMR谱图导出了环化SBR的环化度和溶剂参与量的计算公式。  相似文献   

10.
FTIR和^13C—NMR研究球笼烯钕系聚丁二烯链结构   总被引:1,自引:0,他引:1  
用FTIR和13C-NMR法测定了Nd(naph)3-Al(i-Bu)3-C60衍生物催化体系及添加C60合成的聚丁二烯的链节含量。结果表明,球笼烯钕系聚丁二烯的顺-1,4链节达98.8%,反-1,4链节为0.8%;当添加的C60用量为C60/Bd=1.6×10-4(摩尔比)时,顺-1,4链节降至93.6%,反-1,4链节升至4.6%,反-1,4链节IR特征吸收峰较普通钕系聚丁二烯向高频移动了6cm-1,这表明C60分子与Bd共同参与了向活性中心竞争配位过程。  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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