水溶液中共聚合成MPEGAA-AA-AMPS聚羧酸高效减水剂及其性能

以自制的活性大单体聚乙二醇单甲醚丙烯酸酯(MPEGAA)、丙烯酸(AA)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为原料,在水溶液中共聚合成了MPEGAA-AA-AMPS高效减水剂。重点考察了单体的摩尔比、引发剂(APS)用量、反应温度和反应时间等合成条件对MPEGAA-AA-AMPS高效减水剂的影响。结果表明:最佳的高效减水剂的合成条件是:n(MPEGAA)∶n(AA)∶n(AMPS)=1∶4.3∶1.10,引发剂APS用量为单体总质量的5%,聚合温度和反应时间分别为80℃和5 h。在该条件下合成的MPEGAA-AA-AMPS高效减水剂,其分散性和保塑性理想,减水增强效果明显。     

高性能聚羧酸减缩材料的研发(Ⅱ)——高分子聚合物(HP-SRA)的合成与表征

以减缩活性单体2-(2-丁氧乙氧基)乙醇丙烯酸酯(MBDEGAA)、丙烯酸(AA)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)与聚乙二醇单甲醚丙烯酸酯(MPEGAA)为聚合单体,在水溶液中通过聚合反应,合成了一种高分子聚合物(HP-SRA)。采用红外光谱、核磁共振氢谱和凝胶渗透色谱对HP-SRA分子结构和相对分子质量及其分布进行了表征。并测定了掺入质量分数为0.30%(固含量)的HP-SRA混凝土的减缩性能及应用性能。结果表明,当n(MPEGAA)∶n(MBDEGAA)∶n(AA)∶n(AMPS)=1∶2.15∶2.15∶1.10时,水泥砂浆减缩率最高,水泥净浆流动度及其保持能力最佳。在不影响混凝土应用性能基础上,减缩基团的引入有利于提高混凝土的减缩性能。     

聚羧酸高效陶瓷减水剂的合成及性能

以马来酸酐(MA)、丙烯酸(AA)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为单体,采用水溶液聚合法制备了一种线型MA/AA/AMPS聚羧酸高效陶瓷减水剂。通过正交实验,研究了各反应条件对添加了0.35%(相对于绝干料浆质量)线型MA/AA/AMPS聚羧酸高效陶瓷减水剂的陶瓷坯体料浆流动时间的影响,并进一步利用FTIR和XRD等手段对线型MA/AA/AMPS聚羧酸高效陶瓷减水剂的官能团结构和晶相结构进行了表征,分别用POM和SEM照片观察陶瓷坯体料浆的分散情况和陶瓷坯体试样的断面形貌。结果表明,线型MA/AA/AMPS聚羧酸高效陶瓷减水剂最佳合成条件为:聚合温度为80℃、引发剂用量占聚合单体总质量的9%、n(MA)∶n(AA)∶n(AMPS)=1.0∶3.5∶1.5、聚合时间为4 h。当线型MA/AA/AMPS聚羧酸高效陶瓷减水剂掺量为0.35%(相对于绝干料浆质量)时,陶瓷坯体料浆体系的黏度从689.5 mPa·s降低到56.8 mPa·s。     

基于正交试验设计的聚羧酸高效陶瓷减水剂性能

以马来酸酐(MA)、丙烯酸(AA)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为单体,采用水溶液聚合法制备了一种线型MA/AA/AMPS聚羧酸高效陶瓷减水剂。通过正交试验,研究了各反应条件对添加了0.35%(相对绝干料浆)线型MA/AA/AMPS聚羧酸高效陶瓷减水剂的陶瓷坯体料浆流动时间的影响,并进一步利用FT-IR和XRD等手段分别对线型MA/AA/AMPS聚羧酸高效陶瓷减水剂的官能团结构和晶相结构进行表征,分别用POM和SEM照片观察陶瓷坯体料浆的分散情况和陶瓷坯体试样的断面形貌。结果表明,线型MA/AA/AMPS聚羧酸高效陶瓷减水剂最佳合成条件为：聚合温度为80 ℃、引发剂用量占聚合单体总质量的9%、n(MA)∶n(AA)∶n(AMPS)=1.0∶3.5∶1.5和聚合时间为4 h。当线型MA/AA/AMPS聚羧酸高效陶瓷减水剂掺量为0.35%(相对绝干料浆)时,陶瓷坯体料浆体系的黏度从689.5 mPa穝降低到56.8 mPa穝。     

环糊精改性聚羧酸系减水剂的制备与性能

以丙烯酸(AA)、甲基丙烯磺酸钠(MAS)、马来酸酐接枝β-环糊精(MAH-β-CD)和甲基烯丙基聚氧乙烯醚(APEG)为原料,通过水溶液自由基共聚制备了β-CD改性聚羧酸系减水剂(MPC)。考察了反应物摩尔比、引发剂用量、反应时间及反应温度对减水剂性能的影响。当单体摩尔比n(AA)∶n(MAS)∶n(MAH-β-CD)∶n(APEG)=5∶0.5∶0.1∶1、引发剂过硫酸铵(APS)用量为单体总质量的5%、反应温度为90℃、反应时间为5 h时,所得减水剂性能较好。应用结果表明,掺MPC后水泥净浆流动度可达306 mm、初凝时间为440 min、减水率达32.2%。SEM和强度测试结果表明,掺有MPC的水泥石的结构更加紧密匀质,孔洞更加微小,有利于混凝土后期结构的发展。     

一种高性能醚型聚羧酸系减水剂的合成研究

设计四元单体共聚体系,以聚乙二醇异戊烯丙基醚2400(TPEG)、丙烯酸(AA)、甲基丙烯磺酸钠(SMAS)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)在过硫酸铵(APS)为引发剂存在下共聚,一步法合成高性能的聚羧酸减水剂。经正交实验优选出最佳合成工艺条件如下:AA/TPEG摩尔比为3∶1;AMPS/TPEG摩尔比为0.3∶1,SAS/TPEG摩尔比为0.8∶1,引发剂APS的用量为共聚单体总质量的4%,反应温度为70℃、反应时间为8 h。所合成的聚羧酸减水剂具有优异的减水性能和良好的保坍性能,并能大幅提高所得混凝土拌合物的强度。     

大分子单体聚乙二醇单甲醚丙烯酸酯(MPEGAA)的合成

以聚乙二醇单甲醚(MPEG-1200)与丙烯酸(AA)为主要原料,采用直接酯化法合成聚羧酸系高效减水剂大分子单体聚乙二醇单甲醚丙烯酸酯(MPEGAA).通过正交试验确定各单体的用量.结果表明:n(AA)/n(MPEG)=3.5∶1,阻聚剂对苯二酚用量(以占MPEG与AA总质量分数计)为1.2％,催化剂对甲苯磺酸用量(以占从质量分数计)为5.5％,酯化反应温度为95℃,酯化反应时间为6h是合成大分子单体的最佳酯化工艺条件.以最佳酯化工艺条件合成的大单体为原料制备的MPEGAA-AA-AMPS聚羧酸高效减水剂,具有良好的分散性和分散保持性.当掺量(折固掺量)为0.15％时,水泥净浆初始流动度达300 mm,经过1h时为315mm,2h后仍保持在290 mm.     

P(AA-co-DMC)/MPEGAA两性型聚羧酸超塑化剂的研制及其性能

以阴、阳离子功能性单体(AA、DMC)与聚乙二醇单甲醚丙烯酸酯大分子单体(MPEGAA)主要原料,采用水溶液自由基聚合法,合成了一种P(AA-co-DMC)/MPEGAA两性型聚羧酸超塑化剂.通过FTIR、1H NMR分析了所合成两性型聚羧酸超塑化剂分子结构,结果表明已得到预期结构的P (AA-co-DMC)/MPEGAA两性型聚羧酸超塑化剂.同时,研究了水泥净浆流动度及聚合反应转化率随n(AA)∶n(DMC)∶ n(MPEGAA)、引发剂用量w(K2S2O8)(以占单体总质量计,下同),聚合反应温度Tcr,反应恒温时间tcr的变化规律,结果表明:n(AA)∶n(DMC)∶n(MPEGAA)=0.50∶ 0.10∶0.25,w(K2S2O8) =5.0％,tcr=60℃,t.r=3h是制备P(AA-co-DMC)/MPEGAA两性型聚羧酸超塑化剂的最佳工艺条件.并测定了添加质量分数为2.0％的两性型聚羧酸超塑化剂混凝土性能,结果显示:以最佳合成工艺条件制得的P(AA-co-DMC)/MPEGAA两性型聚羧酸超塑化剂,在混凝土中具有优越分散保持性能和较高早期强度性能.     

微波作用下酰胺型聚羧酸减水剂的合成及其性能研究

在微波作用下,以自制活性大单体聚乙二醇丙烯酸酯(PEGAA)、马来酸酐(MAH)、丙烯酰胺(AM)及甲基丙烯磺酸钠(SMAS)为主要原料,过硫酸铵(APS)为引发剂,制备性能优异的酰胺型聚羧酸减水剂,考察各单体用量、微波功率、反应时间等因素对减水剂性能的影响。结果表明,合成酰胺型聚羧酸减水剂最佳工艺为:n(MAH)∶n(PEGAA)∶n(SMAS)=2.5∶1∶0.5,AM、APS质量分数分别为反应物总质量的9%和4%,微波功率300 W及反应时间25 min。与传统的水浴相比,该工艺高效、节能,产品性能优异,在聚羧酸减水剂掺量0.5%条件下,水泥净浆流动度达275 mm,砂浆减水率32.5%,且前期具有缓凝作用,后期对胶砂抗压强度增强显著,具有良好的工业应用前景。     

微波作用下酰胺型聚羧酸减水剂的合成及其性能研究

在微波作用下,以自制活性大单体聚乙二醇丙烯酸酯(PEGAA)、马来酸酐(MAH)、丙烯酰胺(AM)及甲基丙烯磺酸钠(SMAS)为主要原料,过硫酸铵(APS)为引发剂,制备性能优异的酰胺型聚羧酸减水剂,考察各单体用量、微波功率、反应时间等因素对减水剂性能的影响。结果表明,合成酰胺型聚羧酸减水剂最佳工艺为:n(MAH)∶n(PEGAA)∶n(SMAS)=2.5∶1∶0.5,AM、APS质量分数分别为反应物总质量的9%和4%,微波功率300 W及反应时间25 min。与传统的水浴相比,该工艺高效、节能,产品性能优异,在聚羧酸减水剂掺量0.5%条件下,水泥净浆流动度达275 mm,砂浆减水率32.5%,且前期具有缓凝作用,后期对胶砂抗压强度增强显著,具有良好的工业应用前景。     

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。