原位聚合制备抗紫外芳香族支链锦纶6及其应用

通过添加均苯四甲酸二酐进行原位聚合制备抗紫外芳香族支链锦纶6(PA6-Ti O2)母粒,后与线型PA6进行共混纺丝,研究了抗紫外芳香族支链PA6的聚合工艺、纺丝工艺,探索支链PA6对纤维热学性能、加工性能、力学性能等的影响。结果表明:随着均苯四甲酸二酐含量的增加,芳香族支链PA6聚合熔体黏度减小,相对黏度逐渐降低,表明芳香族支链PA6的流动性增加;其结晶熔融温度逐渐降低,在相同纺丝温度下螺杆压力下降,表明可以有效改善其加工性能,但对纤维的力学性能有一定的影响;制备的抗紫外纤维在280~320 nm波长内,紫外线透过率小于10%,具有较好的紫外线遮蔽性能,从纤维断面扫描电镜(SEM)谱图可见基体相容性好。     

PES/PA6的共混纺丝及其性能研究

将不同质量比的聚醚砜(PES)与聚酰胺6(PA6)共混进行熔融纺丝制得PES/PA6共混纤维;研究了共混物的流动性及其纺丝工艺,以及PES/PA6共混纤维的热稳定性和力学性能。结果表明:PA6的加入显著提高了PES的流动性,降低了纺丝温度,改善了PES的可纺性;与纯PES纤维相比,PES/PA6共混纤维的起始热分解温度有所降低,PES/PA6质量比为70/30～30/70的PES/PA6共混物的纺丝温度为320～340℃,卷绕速度为100～400 m/min,纤维的断裂强度为0.71～2.25 cN/dtex。     

Er_2O_3改性尼龙6的制备及性能研究

用熔融纺丝法成功制备了PA6/PP-g-MAH/Er2O3纤维材料,采用DSC、FTIR研究Er2O3对尼龙6的结构性能影响,通过检测混合样品的熔融指数、拉伸强度和断裂伸长率研究Er2O3对尼龙6的力学性能影响。结果表明:当Er2O3的添加量为4 phr时,PA6/PP-g-MAH/Er2O3初生纤维强度提高了51%,断裂伸长率增加了10.6%,同时结晶温度降低,熔融温度降低,熔体流动速率提高。     

LDPE/PA6海岛复合超细纤维的可纺性及性能研究

采用熔融复合纺丝法制备了低密度聚乙烯(LDPE)/聚己内酰胺(PA6)海岛复合超细纤维,讨论了纺丝温度、海岛比例和纺丝速度对纤维的可纺性、结构和性能的影响。结果表明:在纺丝温度为278℃,LDPE/PA6质量比为50/50,45/55,40/60,35/65,30/70,冷却长度为140 mm,纺丝速度为1 000 m/min时,海岛复合纤维具有良好的可纺性和海岛结构,其超细纤维线密度为0.077~0.110 dtex;在PA6质量分数为55%条件下,提高纺丝速度,PA6超细纤维的直径进一步降低,力学性能增加,但不匀率上升。     

PA6/LDPE/PE-g-MAH共混纳米纤维的制备及结构研究

采用共混海岛纺丝法制备聚酰胺6/低密度聚乙烯/聚乙烯接枝马来酸酐(PA6/LDPE/PE-g-MAH)共混纤维,溶解剥离出LDPE基体相,可制备出PA6纳米纤维;研究了共混物的组成和纺丝条件对共混纤维的相结构、结晶、力学性能及PA6纳米纤维直径的影响。结果表明:随着共混物中PA6分散相含量增加,PA6纳米纤维的直径逐渐增大;PA6质量分数从30%增加至60%时,PA6纳米纤维平均直径由107 nm增至149nm;PA6质量分数为70%时,由于相逆转无法得到PA6纳米纤维;在PA6质量分数为55%条件下,提高拉伸倍数,PA6纳米纤维的直径进一步降低,且结晶度、力学性能增加。     

离子液体增塑聚酰胺6纤维的制备与性能表征

在聚酰胺6(PA 6)中添加离子液体对其进行增塑改性制得离子液体增塑PA 6切片,再经熔融纺丝、拉伸、定型,制备离子液体增塑PA 6纤维,然后对纤维试样进行水洗;探讨了离子液体含量对增塑PA 6纤维的热性能、动态力学性能、取向及力学性能的影响以及水洗之后纤维力学性能的变化。结果表明:随着离子液体添加量的增加,增塑PA 6纤维的熔融温度与结晶温度逐渐下降,纤维分子链的活动性增加,玻璃化转变温度逐渐下降;离子液体并未提高增塑PA 6纤维的取向度;随着离子液体含量的增加,增塑PA 6纤维的断裂强度先增加后降低,断裂伸长率呈下降趋势;在离子液体质量分数为1.5%、拉伸倍数为3.6时,增塑PA 6纤维的断裂强度最高,达3.89 cN/dtex,纤维水洗后断裂强度大幅度提高,达6.36 cN/dtex。     

超支化聚合物改性PA6的研究

将芳香族超支化聚合物(HBP)与PA6共混、造粒、纺丝,研究PA6/HBP共混体系的结晶性能及纺丝工艺。结果表明:与PA6相比,HBP的加入对PA6的结晶温度和取向度无明显影响,结晶度提高,其晶型发生变化,γ晶型增强,α晶型略有减弱,HBP以加入质量分数为0.05%较好。PA6/HBP共混体系的熔体流动指数较PA6的明显提高,其纺丝温度明显降低,PA6/HBP纤维的断裂强度有所下降。HBP以加入质量分数为0.05%较好。     

高流动性PA 6超细纤维的制备及其性能研究

采用自制的高流动性聚己内酰胺(HPA 6)、普通聚己内酰胺(PA 6)、低密度聚乙烯(LDPE)为原料,通过共混纺丝法分别制备HPA 6/LDPE定岛纤维和HPA 6/PA 6/LDPE不定岛纤维,溶解去除LDPE,得到一系列HPA 6超细纤维;研究了HPA 6的可纺性及其超细纤维的线密度、力学性能、染色性能等。结果表明:由于HPA 6在纺丝温度下较好的流动性和高支化结构及大量末端基团,HPA 6可纺性良好;HPA 6/LDPE质量比为70/30时,157.4 dtex/36 fHPA 6超细纤维断裂强度为3.85 c N/dtex,断裂伸长率为14%,染色深度为1.809,色牢度达5级;HPA 6超细纤维的力学性能和染色性能优异,与PA 6超细纤维性能相当,可拓展其在纤维领域的应用。     

地下工程用纤维增强复合材料的制备与性能研究

为了提升地下工程用纤维增强复合材料的力学性能,采用熔融共混方法制备多种玻璃纤维添加量的纤维增强复合材料,研究了玻璃纤维添加量对复合材料密度和灰分、熔融和结晶以及力学性能的影响。结果表明,添加玻璃纤维制备得到的PA66/GF复合材料的密度和灰分都大于PA66,且随着玻璃纤维添加量的增大,PA66/GF复合材料的密度和灰分都逐渐增大;纤维增强尼龙复合材料中添加20%～30%的玻璃纤维不会显著改变复合材料的熔点,但是结晶温度有所提升、结晶时间明显缩短。研究结果将有助于高性能地下工程用纤维增强复合材料的开发与应用。     

苯并三唑/纳米TiO_2改性PPS纤维的制备及性能

为了改善聚苯硫醚(PPS)纤维的光稳定性能,将苯并三唑与纳米二氧化钛(Ti O2)按一定比例复配与PPS切片进行共混熔融纺丝,制得改性PPS纤维,研究了改性PPS纤维的可纺性及其性能。结果表明:苯并三唑/纳米Ti O2复配物的质量分数大于1.5%时,改性PPS纤维的可纺性变差;当复配物质量分数小于等于1.5%时,改性PPS纤维的表观形貌和可纺性满足工业生产要求;随着苯并三唑/纳米Ti O2的添加量增加,改性PPS纤维的断裂强度有所降低,断裂伸长率和热性能变化不大;当苯并三唑质量分数为1.5%,Ti O2为0时,PPS的结晶速率最大,改性PPS纤维的光稳定性能最好,光照前后的色度变化值为14.02。     

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。