Influence of the degree of grafting on the morphology and mechanical properties of blends of poly(butylene terephthalate) and glycidyl methacrylate grafted poly(ethylene-co-propylene) (EPR)

Poly(ethylene-co-propylene) (EPR) was functionalized to varying degrees with glycidyl methacrylate (GMA) by melt grafting processes. The EPR-graft-GMA elastomers were used to toughen poly(butylene terephthalate) (PBT). Results showed that the grafting degree strongly influenced the morphology and mechanical properties of PBT/EPR-graft-GMA blends. Compatibilization reactions between the carboxyl and/or hydroxyl of PBT and epoxy groups of EPR-graft-GMA induced smaller dispersed phase sizes and uniform dispersed phase distributions. However, higher degrees of grafting (>1.3) and dispersed phase contents (>10 wt%) led to higher viscosities and severe crosslinking reactions in PBT/EPR-graft-GMA blends, resulting in larger dispersed domains of PBT blends. Consistent with the change in morphology, the impact strength of the PBT blends increased with the increase in EPR-graft-GMA degrees of grafting for the same dispersion phase content when the degree of grafting was below 1.8. However, PBT/EPR-graft-GMA1.8 displayed much lower impact strength in the ductile region than a comparable PBT/EPR-graft-GMA1.3 blend (1.3 indicates degree of grafting).

Brittle-ductile transition in PP/EPDM blends: effect of notch radius

The toughness of polypropylene (PP)/ethylene-propylene-diene monomer (EPDM) blends was studied over wide ranges of EPDM content and temperature. In order to study the effect of notch radius (R), the toughness of the samples with different notch radii was determined from Izod impact test. The results showed that both toughness and brittle-ductile transition (BDT) of the blends were a function of R, respectively. At test temperatures, the toughness tended to decrease with increasing 1/R for various PP/EPDM blends. Moreover, the brittle-ductile transition temperature (T-BT) increased with increasing 1/R, whereas the critical interparticle distance (IDc) reduced with increasing 1/R. Finally, it was found that the different curves of IDc versus test temperature (T) for different notches reduced down to a master curve if plotting IDc versus T-BT(m)-T, where T-BT(m) was the T-BT of PP itself for a given notch, indicating that T-BT(m)-T was a more universal parameter that determined the BDT of polymers. This conclusion was well in agreement with the theoretical prediction.

Brittle-tough transition in PP/EPDM blends: effects of interparticle distance and tensile deformation speed

The toughness of polypropylene (PP)/ethylene-propylene-diene monomer rubber (EPDM) blends containing various EPDM contents as a function of the tensile speed was studied. The toughness of the blends was determined from the tensile fracture energy of the side-edge notched samples. A sharp brittle-tough transition was observed in the fracture energy versus interparticle distance (ID) curves when the crosshead speed < 102.4 mm/min. It was observed that the brittle-ductile transition of PP/EPDM blend occurred either by reducing ID or by decreasing the tensile speed. The correlation between the critical interparticle distance and tensile deformation rate was compared with that between the critical interparticle distance and temperature for PP/EPDM blends. (C) 2000 Elsevier Science Ltd. All rights reserved.

Aging in EPDM used for outdoor insulation

The effect of accelerated weather aging an ethylene-propylene-diene monomer(EPDM) rubber used for outdoor insulation was studied by surface roughness measurement and X-ray photoelectron spectroscopy(xps). The surface roughness of EPDM rubber changed with aging time. The surface oxygen and aluminum content were found to increase and that of carbon, silicon and nitrogen to decrease with time. The detailed XPS analysis indicated that the concentration of carbon in C-C decreased and that of highly oxidized carbons in C-O, C=O and O=C-O increased with time, which was due to the oxidation of EPDM rubber polymer. The appearance of O=C-O on the surface of EPDM rubber was a signal that EPDM rubber became aged. The aging speed decreased with time. The aging mechanism is discussed also.

STRUCTURE AND PROPERTIES OF SEQUENTIALLY POLYMERIZED PROPYLENE-B-[ETHYLENE-CO-PROPYLENE]-B-PROPYLENE COPOLYMERS

The structure and properties of presumed block copolymers of polypropylene (PP) with ethylene-propylene random copolymers (EPR), i.e., PP-EPR and PP-EPR-PP, have been investigated by viscometry, transmission electron microscopy, dynamic mechanical analysis, differential scanning calorimetry, gel permeation chromatography, wide-angle x-ray diffraction, and other techniques testing various mechanical properties. PP-EPR and PP-EPR-PP were synthesized using delta-TiCl3-Et2AlCl as a catalyst system. The results indicate that the intrinsic viscosity of these polymers increases with each block-building step, whereas the intrinsic viscosity of those prepared by chain transfer reaction (strong chain-transfer reagent hydrogen was introduced between block-building steps during polymerization) hardly changes with the reaction time. Compared with PP / EPR blends, PP-EPR-PP block copolymers have lower PP and polyethylene crystallinity, and lower melting and crystallization temperatures of crystalline EPR. Two relaxation peaks of PP and EPR appear in the dynamic spectra of blends. They merge into a very broad relaxation peak with block sequence products of the same composition, indicating good compatibility between PP and EPR in the presence of block copolymers. Varying the PP and EPR content affects the crystallinity, density, and morphological structure of the products, which in turn affects the tensile strength and elongation at break. Because of their superior mechanical properties, sequential polymerization products containing PP-EPR and PP-EPR-PP block copolymers may have potential as compatibilizing agents for isotactic polypropylene and polyethylene blends or as potential heat-resistant thermoplastic elastomers.

FACTOR-ANALYSIS APPLIED TO X-RAY-DIFFRACTION DIAGRAMS OF POLYMER BLENDS

The feasibility of applying the method of factor analysis to X-ray diffraction diagrams of binary blends of polypropylene and ethylene-propylene-diene terpolymer (PP/EPDM) was examined. The result of mathematical treatment was satisfactory. The number of scattering species and their concentrations in six kinds of PP/EPDM blends were determined. The separation of the spectral peaks of each species in the blends, contributing spectral intensities, was carried out.

Laurendecumallenes A-B and laurendecumenynes A-B, halogenated nonterpenoid C-15-Acetogenins from the marine red alga Laurencia decumbens

Four new halogenated nonterpenoid C-15-acetogenins, 4:7,6:13-bisepoxy-9,10-diol-1,12-dibromopentadeca-1,2-diene (1, laurendecumallene A), 4:7,6:12-bisepoxy-9,10-diol-1,13-dibromopentadeca-1,2-diene (2, laurendecumallene 13), (3Z)-6:10,7:13-bisepoxy-12-bromo-9-hydroperoxylpentadeca-3-en-1-yne (3, laurendecumenyne A), and (3Z)-6:10,9:13-bisepoxy-12-bromo-7-chloropentadeca-3-en-1-yne (4, laurendecumenyne 13), together with one known halogenated C-15-acetogenin elatenyne (5) were isolated and identified from the organic extract of the marine red alga Laurencia decumbens. Their structures and relative stereochemistry were established by means of spectroscopic analysis including UV, IR, high-resolution electrospray ionization mass spectrometry (HRESIMS), and ID and 2D NMR techniques. All these metabolites were submitted for the cytotoxic assay against tumor cell line A549 (human lung adenocarcinoma), but all of them were found inactive (IC50 > 10 mu g/mL).

Brominated Selinane Sesquiterpenes from the Marine Brown Alga Dictyopteris divaricata

Two new brominated selinane sesquiterpenes, 1-bromoselin-4(14), 11-diene (1) and 9-bromoselin-4(14), 11-diene (2), one known cadinane sesquiterpene, cadalene (3), and four known selinane sesquiterpenes, alpha-selinene (4), beta-selinene (5), beta-dictyopterol (6), and cyperusol C (7), were isolated from a sample of marine brown alga Dictyopteris divaricata collected off the coast of Yantai (China). Their structures were established by detailed MS and NMR spectroscopic analysis, as well as comparison with literature data.

Halogenated Sesquiterpenes from the Marine Red Alga Laurencia saitoi (Rhodomelaceae)

Four new halogenated sesquiterpenes, 10-bromo-3-chloro-2,7-epoxychamigr-9-en-8a-of (1), 2,10 beta-dibromochamigra-2,7-dien-9 alpha-ol (2), (9S)-2-bromo-3-chloro-6,9-epoxybisabola-7(14),10-diene (3), and (9R)-2-bromo-3-chloro-6,9-epoxybisabola-7(14),10-diene (4), were characterized from the marine red alga Laurencia saitoi. In addition, two known halosesquiterpenes, 2,10-dibromo-3-chlorochamigr-7-en-9 alpha-ol (5) and isolaurenisol (6), were also isolated and identified. Their structures were established on the basis of extensive analysis of spectroscopic data.

Millennial-scale paleoceanography in Okinawa Trough during Late Quaternary period

Based on the analyses of foraminifer and accelerator mass spectrometer radiocarbon dating in DGKS9603 core from mid-Okinawa Trough close to bottom, oscillation curve, which expressed the relation between the surface water temperature and the depth, has been obtained by using foraminifer analysis and calculation of FP-12E transfer function. The whole core indicated seven cold phases and eight warm phases. Obvious expression of low temperature event during Middle and Late Holocene, YD,H1,H2,H3 and H4 events, as well as the short cold phase during the middle last glacial period, implied that short shifts since 50 kaBP would have been global significance. Sedimentation rate during cold phases is usually faster than that in warm stages, with the lowest rate in Holocene, which may be connected with rising sea level and principal axial of Kuroshio Current moving to west. Volcanic activities highly developed in Okinawa Trough during the Quaternary period, thus abundant volcanic glass and pumice were well preserved.

从胶州湾海洋放线菌中发现的新型星形孢菌素等7种新结构化合物

本课题组自1999年以来，将培养条件优化、生物活性跟踪及化学跟踪技术应用到胶州湾海洋放线菌的次级代谢产物研究中，发现了一批具有生物活性的新结构化合物。 本研究从青岛胶州湾分离出各类海洋微生物423株，包括海洋放线菌287株，海洋细菌116株，海洋真菌20株，对胶州湾海洋微生物的资源和分布规律有了基本的认识。对其中海洋放线菌的次级代谢产物进行了活性和化学筛选，获得了它们对八种病原微生物的抑制活性数据。发现胶州湾海洋放线菌对至少一种受试微生物具有中等以上拮抗能力的比例为50%。 从三株海洋放线菌的发酵粗提物中鉴定出7个新结构化合物和31个已知化合物。具体是：①从菌株M518中鉴定出21个化合物，包括3个新结构天然化合物：N-Foramidostaurosporine，5,7-Dihydroxy-5,6,7,8-tetrahydro-1H-azocin-2-one，Selina-4(14),7(11)-diene-8,9-diol和1个新结构衍生物Trimer 3。其中化合物5,7-Dihydroxy-5,6,7,8-tetrahydro-1H-azocin-2-one为新骨架类型的天然化合物。② 从菌株M491 中鉴定出10个化合物，包括3个新结构化合物10α-14-Dihydroxyamorph-4-en-3-one，10α,11-Dihydroxyamorph-4-ene，5α,10α,11-Triydroxyamorphan-3-one； 并首次从微生物中分离得到已知化合物10α-Hydroxyamorph-4-en-3-one；③从菌株M311中鉴定出7个已知化合物。 发现天然化合物5,7-Dihydroxy-5,6,7,8-tetrahydro-1H-azocin-2-one很容易发生重排反应，分离出了两个重排反应产物，并得出该化合物可能的重排反应过程及三聚体形成的方式。 生物活性实验结果表明新型星形孢菌素N-Formamidostaurosporine具有很强的抗肿瘤活性：对于37株人类肿瘤细胞的平均IC50，IC70和IC90分别为0.016µg/ml，0.171µg/ml和2.352µg/ml。对37株肿瘤细胞株的抗肿瘤选择性为27%。还首次发现Staurosporine类化合物具有抑制微藻生长的活性。 对产生新化合物的菌株M518 和M491 进行了形态、生理生化及分子鉴定，提交两株菌的16S rDNA 序列到GenBank（DQ184649 和DQ184648）。结合形态、生理生化特征及系统 发育树分析表明：菌株M518 属于链霉菌属，并可能属于该属中的粉红孢类群；菌株M491属于链霉菌属，并可能属于该属中的青色类群。

末次冰盛期以来黑潮流域的古环境演化

2005年6月，中法国际合作在西太平洋海域执行IMAGES XII-MD147 Micro Polo1航次科学考察时，由法国极地研究所R/V Marine Dufresne极地考察船利用Calypso重力取样器于冲绳海槽南部钻取了34.2米长MD05-2908柱状样。本文利用AMS14C测年数据建立了该孔的年代模型，对该孔的浮游有孔虫动物群落进行了分析，并利用FP-12E浮游有孔虫转换函数和Q型因子分析方法对该孔浮游有孔虫数据进行了研究，对全新世以来的黑潮流系演化和古环境记录进行了讨论。 结果表明，中晚全新世存在着5次洪水爆发期，洪水爆发期与当时温暖气候相对应，而高海平面对洪水的爆发也产生了影响。进入全新世以来的6790～4000a B.P.期间，黑潮流一直有稳步增强的趋势，黑潮流始终位于冲绳海槽内；4000～3000a B.P.期间，黑潮强度减弱或者发生明显东偏，冲淡水影响增强；3000a B.P.以后黑潮强度逐渐增强，1650～0a B.P.为中晚全新世以来黑潮活动最强的时期,在600a B.P.和140a B.P.左右存在低值，黑潮强度短暂减弱。普林虫低值事件在MD05-2908孔中有很好的体现，对该事件进行了进一步定年，其发生时间为3900～2800a B.P.，持续时间为1100a，该事件的发生可能与东亚冬季风加强有关。 冲绳海槽中晚全新世气候变化可以分为四个阶段： 6790～4800a B.P.低温阶段，4800～4100a B.P.高温阶段，4100～2400a B.P.低温阶段，2400～0a B.P.波动高温阶段。通过与中国及世界其它地方对比可以识别出6.3～5.9、5.5、4.6～4.2、3.6～3.0、2.9～2.4、1.3～1.0、0.5～0.1ka B.P.六个降温事件，为全新世气候波动在深海高分辨率沉积记录中的响应提供了有力支持。该孔SST频谱分析结果显示，存在着3008a、1061a这种千年尺度的周期，以及215a、123a、103～107a、81～78a以及73～71a等周期，表明该孔SST变化与太阳活动强度是密切相关的。 中晚全新世以来，黑潮流在冲绳海槽逐步加强，到4000aB.P.左右达到最大，然后4000～3000a B.P.期间，黑潮强度明显减弱或者发生东偏，3000aB.P.以后，黑潮强度持续增强，在近1000aB.P.波动较大。 对冲绳海槽地区14个柱状样氧同位素以及P.obliquiloculata丰度进行研究，发现LGM以来，黑潮流可能仍然在冲绳海槽地区活动，并没有移出海槽外，但是由于其强度减弱，其流径发生了很大变化。

三种海洋红藻和两株放线菌次级代谢产物研究

海洋是一个巨大的天然产物宝库，约占地球表面积70%的海洋蕴藏着80%的生物资源。由于海洋生态环境的特殊性，导致海洋生物能够产生大量结构独特多变和活性特殊多样的代谢产物。我国海域辽阔，海洋资源丰富，为寻找结构新颖、生理活性独特的先导化合物，加强对海洋资源的开发利用，本论文对中国沿海的三种海洋红藻和两株放线菌次生代谢产物以及生物活性进行研究，为新药研究与开发提供模式结构和药物前体。 对红藻似瘤凹顶藻Laurencia similis乙酸乙酯萃取物进行分离纯化，从中得到单体化合物35个，通过波谱学方法（IR、MS、NMR等）鉴定了他们的结构。分别为：2, 2, 5, 5, 6, 6-sixibromo-3, 3-bi-1H-indole (1)，3,5-dibromo- 1-methyl-indole (2)，3',5',6,6'-tetrabromo-2,4-dimmethyldiphenyl ether (3)，1,2,5- tribromo-3-bromoamino-7-bromomethylnaphthalene (4)，2,5,8-tribromo-3-bromo- amino-7-bromomethylnaphthalene (5)，2,5,6-tribromo-3-bromoamino-7-bromo- methylnaphthalene (6), 2,5,6,5',6'-pentabromo-3,4,3',4'-tetramethoxybenzophenone (7), (4E)-1-bromo-5-[(1'S*,3'R*)-3'-bromo-2',2'-dimethyl-6'-methylenecyclohexyl] -3-methylpent-4-ene-2,3-diol (8)，4-hydroxy-Palisadin C (9)，Isopalisol (10)，Luzonensol (11)，Palisadin B (12)，Aplysistatin (13)，Palisadin A (14)，5-Acetoxypalisadin B (15)，Aristolan-1(10)- en-9-ol (16)，Aristol-8-en-1-one (17)，Aristolan-9-en-1-one (18)，Aristolan-1(10)-en- 9-one (19)，Aristofone (20)，Aristolan-1(10)-8-diene (21)，Aristolan-1,9-diene (22)，10-Hydroxyaristolan-9-one (23)，7,11,15-trimethyl-3-methylene-hexadecan-1,2-diol (24)，3β-Hydroxyergosta- 5,24(28)-dien-7-one (25)，Isofucosterol (26)，β-sitosterol (27)，豆甾-4-烯-3α,6β-二醇 (28)，Cholesta-5-en-3β-ol (29)，Stigmasterol (30)，2,3,5,6-四溴-吲哚 (31)，2,3,6-tribromo-1H-indole (32)，3,5,6-tribromo-1-methylindole (33)，3,5,6-tribromo -1H-indole (34)，2,3,5-tribromo-1-methylindole (35)，其中化合物1-9为新化合物，化合物10-15、20和化合物24-30均为首次从该种海藻中得到。对新化合物1-9进行PTP1B酶抑制剂活性筛选，新化合物1、3、7显示强的PTP1B酶抑制活性。 对红藻齐藤凹顶藻Laurencia saitoi乙酸乙酯萃取物进行分离纯化，从中得到单体化合物11个，通过波谱学方法（IR、MS、NMR等）鉴定了他们的结构，分别为：2-hydroxyl-Luzofuranone (1)，2-hydroxyl-Luzofuranone B (2)，4-hydroxyl-Palisudin C (3)，2-bromo-γ-ionone (4)，Aplysistatin (5)，5-Acetoxypalisadin B (6)，Palisadin B (7)，Palisadin A (8)，Pacifigorgiol (9)，豆甾-4-烯-3α,6β-二醇 (10)，2, 3, 5, 6-四溴-吲哚 (11)，其中化合物1-4为新化合物，所有化合物均为首次从该种海藻中得到。通过MTT法对分离得到的新化合物1-4进行肿瘤细胞毒活性筛选，结果显示4个新化合物对所测肿瘤细胞株均无明显的活性。 对红藻瘤状软骨凹顶藻Chondrophycus papillous乙酸乙酯萃取物进行分离纯化，从中得到单体化合物5个，通过波谱学方法（MS、NMR等）鉴定了他们的结构，分别为邻苯二甲酸二丁酯 (1)，邻苯二甲酸二异辛酯 (2)，胆甾醇 (3)，3,7,11,15-tetramethyl-hexadec-2-en-1-ol (4)，4-羟基苯甲醛 (5)，所有化合物均为首次从该种海藻中得到。 对海洋放线菌M159乙酸乙酯萃取物进行分离纯化，从中得到单体化合物13个，通过波谱学方法（MS、NMR等）鉴定了他们的结构，分别为：5-(4',6'-dihydroxy-6-methyloctyl)furan-2(5H)-one (A)，phenethyl alcohol (1)，4-羟基苯甲醛(2)，anthranilic acid (3)，4-Hydroxy-3-methoxy- phenyl-propionic acid (4)，5-(6,7-dihydroxy-6-methyloctyl)furan-2(5H)-one (5)，p-Hydroxyphenylethyl alcohol (6)，3-Indoleacrylic acid (7)，Indol-3-carboxylic acid (8)，Adenine cordyceposide (9)，腺嘌呤核苷(10)，尿嘧啶核苷(11)，Thymidine (12)，其中化合物A为新化合物。所有化合物均为首次从该株放线菌中得到。 对海洋放线菌L211乙酸乙酯萃取物进行分离纯化，从中得到单体化合物15个，通过波谱学方法（MS、NMR等）鉴定了7个结构，分别为：spatozoate (1)，anthranilic acid (2)，3-Indolylethanol (3)，1-Acetyl-β-carbolin (4)，p-Hydroxyphen- ylethyl alcohol (5)，Indole-3-acetic acid (6)，Indol-3-carboxylic acid (7)，所有化合物均为首次从该株放线菌中得到。

Organic geochemical studies of sinking particulate material in China sea area(I) - Organic matter fluxes and distributional features of hydrocarbon compounds and fatty acids

Sinking particulate material collected from Nansha Yongshu reef lagoon and the continental shelf of the East China Sea by sediment traps has been analyzed and studied for the first time using organic geochemical method. The results show that about half of the sinking particulate organic matter in the two study areas are consumed before reaching the depth of 5 m to the sea floor and the degree of this consumption in Yongshu reef lagoon is larger than that in the continental shelf of the East China Sea. The distributions of hydrocarbons and fatty acids indicate that the minor difference of biological sources of sinking particulate organic matter exists between Yongshu reel lagoon and the continental shelf of the East China Sea, but they mainly come from marine plankton. Stronger biological and biochemical transformations of sinking particulate organic matter are also observed and the intensity of this transformation in Yongshu reef lagoon is greater than that in the continental shelf of the East China Sea. It is found that the occurrence of C-25 highly branched isoprenoid (HBI) diene may be related to the composition of diatom species.

Sesquiterpenes from Laurencia similis

One new sesquiterpene, (4E)-1-bromo-5-[(1'S*, 3'R*)-3'-bromo-2',2'-dimethyl-6'-methylenecyclohexyl]-3-methylpent-4-ene-2,3-diol (1), and fifteen known sesquiterpenes, isopalisol (2), luzonensol (3), palisadin B (4), aplysistatin (5), palisadin A (6), 4-hydroxyl-palisudin C (7), 5-acetoxypalisadin B (8), 10-hydroxyaristolan-9-one (9), aristol-8-en-1-one (10), aristolan-9-en-1-one (11), aristolan-1(10)-en-9-one (12), aristolan-1( 10)-en-9-ol (13), aristolan-1(10), 8-diene (14), aristolan-1,9-diene (15) and aristofone (16), were isolated from a sample of marine red alga Laurencia similis. Their structures were established by detailed NMR spectroscopic analysis and comparison with literature data. Compounds 2-9, and 16 were isolated for the first time from this species. All these metabolites were submitted for a cytotoxicity assay against the tumor cell line BEL7402 (human liver adenocarcinoma), but all of them were found inactive (IC50 > 10 mu g/mL).