共查询到20条相似文献,搜索用时 62 毫秒
1.
采用溶液共混法制备了聚酰胺6(PA 6)/聚酰胺66(PA 66)/热致聚酰胺液晶(TLCPa)共混物,分析了TLCPa对PA 6/PA 66相容性及结晶行为的影响。差示扫描量热法分析表明,TLCPa的加入改善了PA 6和PA 66之间的相容性,PA 6/PA 66共混物结晶受到抑制;傅里叶变换红外光谱研究表明,TLCPa和PA 6、PA 66分子间形成了大量的分子间氢键,是TLCPa改善共混物相容性的主要原因;广角X射线衍射分析表明,TLCPa的加入没有影响共混物的晶型结构,当w(TLCPa)大于10%时,共混物的结晶度明显下降。 相似文献
2.
3.
4.
PA6与EAA共混物分子间相互作用的研究 总被引:3,自引:0,他引:3
在一定温度和剪切力作用下,以机械共混制备了PA6与EAA的共混物。通过溶剂溶解证明在共混过程中形成了部分共聚物,用FTIR研究了PA6与EAA分子间的相互作用,结合DSC探讨了共混中分子间的作用力及对PA6结晶性的影响。发现PA6与EAA共混过程中,有部分接枝物形成,且随着共混物中EAA含量的增加,PA6分子间的相互作用力有所改变。 相似文献
5.
采用熔融挤出的方法制备了聚酰胺6/氯化锂/苯乙烯接枝马来酸酐(PA6/LiCl/SMA)复合材料,研究了SMA用量对PA6/LiCl/SMA复合材料的结晶熔融行为及性能的影响。结果表明:SMA的加入会促进Li+与PA6中酰胺基团的络合作用,破坏PA6分子链间的氢键,另外SMA自身能与PA6分子链发生接枝反应,在双重作用下使复合材料的熔点降低到185.53℃。通过DSC和XRD发现:SMA的加入会促使PA6/LiCl/SMA复合材料的结晶形态由α晶型向γ晶型转变,并能有效提高复合材料的力学性能,当SMA用量为3 phr时,其拉伸强度比未添加SMA时提高了53.02%,冲击强度也有所提高,但复合材料的熔体流动速率会有所下降。 相似文献
6.
研究了不同比例乙烯-乙烯醇无规共聚物(EVOH)和聚酰胺6(PA6)共混物的相容性及性能。扫描电子显微镜下观察结果表明二者具有较好的相容性;红外光谱分析和流变实验证实了EVOH与PA6分子间氢键的存在,氢键的作用会随着EVOH含量的增加而增强;阻透性能的测试表明在PA基体中加入EVOH会极大提高基体的阻透性,在EVOH基体中加入少量的PA6对EVOH的阻透性影响很小。 相似文献
7.
8.
9.
PA6/ABS/PC合金的研制 总被引:4,自引:0,他引:4
以PA6,ABS,PC为基础树脂,ABS-g-MAH为增容剂,二叔丁基过氧化物为引发剂,并加入改性剂等助剂,制备了PA6/ABS/PC合金,研究了增容剂的种类及含量,引发剂的种类,PA6的粘度,ABS的牌号及改性剂的含量对PA6/ABS/PC合金性能的影响。结果表明,采用1.0%-1.2%的ABS-g-MAH,30%的相对粘度2.8-3.0的PA6,40%的1300型PC,28%的ABS及0.5%的改性剂制得的PA6/ABS/PC合金优于日本孟山都公司的PA6/ABS合金。 相似文献
10.
11.
12.
M. S. J. Simmonds W. M. Blaney F. Delle Monache M. Marquina Mac-Quhae G. B. Marini Bettolo 《Journal of chemical ecology》1985,11(12):1593-1599
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
13.
Cheng-Le Zhao Shane Porzio Alan Smith Haiyan Ge H. T. Davis L. E. Scriven 《Journal of Coatings Technology and Research》2006,3(2):109-115
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
14.
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. 相似文献
15.
16.
17.
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.
Peter A. Edwards Grant Striemer Dean C. Webster 《Journal of Coatings Technology and Research》2005,2(7):517-527
Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins.
Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol.
The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and
cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on
the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to
determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model
amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate
functional group is more reactive than a glycidyl ether group.
Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago,
IL. 相似文献
20.
Dongjiang Yang Yao Xu Lei Zhang Shangru Zhai Dong Wu Yuhan Sun 《Journal of Coatings Technology and Research》2006,3(2):127-131
A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by 1H MAS NMR. For direct comparison purposes, an SiO2 coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N2 absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals. 相似文献