ACR—g—VC共聚物的合成与性能研究

由两步乳液聚合合成了核－壳结构型ACR胶乳,并进一步通过ACR胶乳存在下的VC悬浮聚合合成ACR－g-VC共聚物,对接枝共聚物的结构和性能进行表征。结果表明：ACR胶乳的存在影响VC悬乳聚合的稳定性,增加分散剂用量能得到颗粒特性较好的共聚树脂;ACR－g-VC共聚物的溶胶聚合度略低于相同聚合温度的均聚PVC,凝胶含量随共聚组成中ACR含量的增加而增加;ACR－g-VC共聚物的塑化时间小于聚合度接近的均聚PVC,而加工转矩大于均聚ACR－g-VC共聚物的冲击强度随ACR含量的增加而增大,且大于ACR含量相当的PVC／ACR共混物。     

耐热性α—ABS树脂的研制

采用乳液接枝共混,以异丙苯法联产苯酚—丙酮的副产α—甲基苯乙烯为原料和丙烯腈共聚,和ABS树脂共混,制备了α—甲基苯乙烯-丙烯腈-丁二烯-苯乙烯四元接枝共聚物。研究了接枝共混条件、影响产品分子量和性能的因素及其微观相结构。得到当原料比α-甲基苯乙烯/丙烯腈=70/30时,共聚物组成恒定;滴加叔十二硫醇可有效调节分子量;玻璃化温度随α-甲基苯乙烯含量增加而增高,随总挥发物含量增加而降低;产品的冲击强度随α-甲基苯乙烯-丙烯腈共聚体分子量增大或ABS接枝量增加而增加,但加工性能变差。由电镜照片可见胶粒主要为外接枝,两相相容性好。     

CPE—g—VC接枝共聚树脂性能与加工应用研究

本文测试了CPE—g—VC接枝共聚树脂的基本性能,用与PVC共混的方法,研究了CPE—g—VC作为PVC改性剂的力学性能及加工条件的关系,考察了CPE—g—VC共混物的转矩流变行为、毛细管流变行为和可挤出性。结果表明:CPE—g—VC具有许多优良特性。在PVC共混物中,CPE—g—VC较CPE有更好的增韧效果,CPE—g—VC/PVC共混物具有较CPE/PVC共混物高3～4倍左右,较纯PVC高5～8倍左右的抗冲击强度。同CPE/PVC共混物相似,CPE—g—VC/PVC共混物加工区域较狭窄。     

具有特高抗冲击强度的共聚树脂CPE—g—VC通过技术鉴定

一种新型改性聚氯乙烯树脂—氯化聚乙烯—氯乙烯接枝共聚树脂(CPE—g—VC),元月廿一日在安徽省化工研究所通过鉴定。接枝共聚树脂的性能通常都优于机械共混物。CPE—g—VC树脂比目前采用的CPE/PVC共混物具有更好的冲击韧性,其硬制品的缺口冲击强度可增高数倍,而且使用方便,价格低廉,适合于加     

PVC/α-MSAN/ASA共混物的结构与性能研究

采用乳液聚合技术合成了一系列不同核壳比的丙烯酸丁酯-苯乙烯-丙烯腈接枝共聚物(ASA)和组成为69/31的α-甲基苯乙烯-丙烯腈共聚物(α-MSAN)。将ASA接枝共聚物与聚氯乙烯(PVC)和α-MSAN熔融共混制备了PVC/α-MSAN/ASA共混物,利用扫描电子显微镜(SEM)和差示扫描量热仪(DSC)对该共混体系的性能与形态进行了表征。结果表明:随着体系中橡胶含量的增加,PVC/α-MSAN/ASA共混物的冲击强度先增大后减小,拉伸强度则逐渐降低,其中橡胶含量为15%的共混物具有较高的韧性;当ASA接枝共聚物的核壳比逐渐增大时,共混物的冲击强度先增大后减小,而拉伸强度基本不变;此外,共混试样的断面形态与其力学性能相符。     

PVC/MBS共混物的形态及力学性能

采用种子乳液聚合方法,在聚丁二烯乳胶粒子上接枝甲基丙烯酸甲酯（MMA）和苯乙烯（St）,制得MBS核壳接枝共聚物,并将其作为增韧剂与聚氯乙烯（PVC）共混制备PVC/MBS共混物。考察了接枝不同MMA和St含量的MBS在PVC中的分散状态及其对PVC/MBS共混物力学性能。结果表明,当MBS壳层中MMA含量增加时,MBS粒子在PVC基体中的分散状态被改善;PVC/MBS共混物的冲击强度随之增加,冲击强度最高时为1117.74 J/m;当MBS中接枝少量St时,PVC/MBS共混物呈现韧性断裂,冲击值最高时为1039.33 J/m;当MBS接枝大量St时,会产生内包容现象,不利于提高PVC共混物的冲击强度。     

CPVC／PVC／CPE三元共混改性的应用

研究了CPVC/PVC/CPE三元共混物的物理力学性能和流变性能。结果表明 :共混物的维卡软化温度、拉伸屈服强度和熔体粘度随CPVC用量的增加而明显增加 ;CPE的用量为 4～ 8份时可明显改善共混物的冲击强度     

PVC-C/PVC共混材料的性能研究

采用氯化聚乙烯（CPE）对氯化聚氯乙烯（PVC—C）进行抗冲改性,将改性后的PVC—C与PVC进行共混,研究了PVC-C／PVC配比对PVC-C／PVC共混物力学性能、耐热性能及流变形能的影响。结果表明,PVC—C／PVC共混物的维卡软化点随PVC—C的用量增加而上升,在50／50（质量比）处有一拐点,大于50／50时上升更快些。共混物的拉伸强度、弯曲强度和熔体黏度随PVC—C用量的增加而提高;混物中随PVC—C用量增加,塑化时间缩短,塑化能力增强,而冲击强度和断裂伸长率却随PVC—C用量增加而下降。共平衡转矩增加。     

CPE三元接枝共聚物对CPE／AS共混物的改性研究

在高分子共混增容理论与高分子共混物多相体系流变学的指导下，利用合成的CPE与AN，St的三元接枝共聚物对CPE/AS共混体系进行改性。扫描电镜（SEM）测试结果表明三元接枝共聚物加入CPE/AS共混体系后能有效改善体系相容性。增容作用明显。流变性能测试表明，一定量的CPE三元接枝共聚物加入CPE/AS共混体系后，能有效降低体系的熔体粘度，克服了增容与共混熔体粘度增加的矛盾。制备出具有良好力学与加工性能的CPE/CPE三元接枝共聚物/AS共混材料。讨论了共混体系的增容机理与加工流动性改善的原因。研究表明，共混材料中CPE，AS，CPE三元接枝共聚物的含量分别为30，60，10（质量份）时，其综合性能优良。     

SAN共聚物中AN含量对PVC/ABS/DOP共混物结构与性能的影响

采用半连续乳液聚合技术将聚苯乙烯(St)和丙烯腈(AN)接枝到聚丁二烯(PB)乳胶粒子上,通过改变共聚单体的投料比(St/AN)合成了一系列不同AN含量的丙烯腈-丁二烯-苯乙烯共聚物(ABS)接枝共聚物,将其与聚氯乙烯(PVC)和增塑剂邻苯二甲酸二辛酯(DOP)熔融共混制得PVC/ABS/DOP(40/40/20)共混物。研究了共混物的热挺型性、微观形态结构和动态力学性能。结果发现,该共混物为双相连续结构,随着接枝SAN共聚物中AN含量的增加,由于DOP小分子与SAN共聚物的相互作用逐渐减弱,导致了SAN相的Tg和共混物的储能模量不断提高,改善了共混物的热挺型性,阐明了PVC/ABS/DOP共混物热挺型性的科学本质。     

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。