EPDM—g—MMA接枝率对POM／EPDM共混物增容作用的影响

本文介绍以ＢＰＯ为引发剂，合成接枝共聚物ＥＰＤＭ－ｇ－ＭＭＡ的方法，并对其进行红外表征，另外，借助ＳＥＭ和力学性能测试研究了接枝率时ＰＯＭ／ＥＰＤＭ共混物的增容作用的影响。     

PA－66／（PE／EPDM）－g－MAH共混增韧的研究

本文研究了尼龙－６６（ＰＡ－６６）与聚乙烯（ＬＤＰＥ）共混物的力学性能。结果表明，用马来酸酐接枝聚乙烯和三元乙丙橡胶（ＥＰＤＭ）改善了与基体ＰＡ－６６的相容性。添加弹性体ＥＰＤＭ，使之生成（ＰＥ／ＥＰＤＭ）－ｇ－ＭＡＨ共聚物，可以大幅度度地提高ＰＡ－６６／（ＰＥ／ＥＰＤＭ）－ｇ－ＭＡＨ冲击强度，同时熔体粘度随温度的变化趋于平缓，吸水率有所下降。     

马来酸酐接枝EPDM及对尼龙的改性

讨论了以来酸酐熔融接枝ＥＰＤＭ的制备工艺、反应机理及ＭＡＨ－ｇ－ＥＰＤＭ的接枝率，分别了ＭＡＨ－ｇ－ＥＰＤＭ与尼龙的相容性及对尼龙力学强度的影响。结果表明添加少量ＭＡＨ－ｇ－ＥＰＤＭ可显著提高尼龙的韧性。     

溶液法马来酸酐接枝EPDM的研究及对尼龙的相容,增韧效应

本文介绍采用溶液法制备马来酸酐（ＭＡＨ）接枝乙丙橡胶（ＥＰＤＭ）以及该接枝物对尼龙（ＰＡ）的相容、增韧效应。研究了引发剂ＢＰＯ和ＭＡＨ用量与接枝率、接枝效率、交量的关系，当ＭＡＨ／ＥＰＤＭ为１０／１００（质量比，下同）时，ＢＰＯ／ＥＰＤＭ的最佳值约为２．２８／１００；固定ＢＰＯ／ＥＰＤＭ为１０／１００时，ＭＡＨ／ＥＰＤＭ的最佳值约为１２．５／１００。由Ｍｏｌａｕ实验表明，ＭＡＨ接枝ＥＰＤＭ／ＰＡ比     

顺酐化EPDM的合成及其对聚甲醛／顺丁橡胶的增容作用

在ＥＰＤＭ，顺丁烯二聚酐的二甲苯溶液中，加入质量浓度为０．０２５ｋｇ／Ｌ的引发剂过氧化苯甲酰，在１００－１３９℃下进行顺酐化反应，可制备顺酐化ＥＰＤＭ。结果表明，在ＢＰＯ／ＥＰＤＭ为０．００６，ＭＡＨ／ＥＰＤＭ为０．２８４时，产物结构ＭＡＨ质量分数约２０％，ＭＡＨ利用率约７０％。     

EPDM／CPE阻燃硫化胶

ＥＰＤＭ／ＣＰＥ阻燃硫化胶王瑞芝（青岛密封工业公司，２６６０３１）１实验部分氯化聚乙烯（ＣＰＥ），江苏太仓塑料助剂厂生产，氯含量为３４％～３６％，Ｔｇ为－２０～１０℃。三元乙丙橡胶（ＥＰＤＭ），牌号为４０４５，日本三井石油化学公司产品。将ＣＰＥ与其他...     

用顺酐化EPDM增容的EPDM改性聚甲醛

以顺酐化三元乙丙橡胶（ＭＥＰＤＭ）为增容剂，研究了ＥＰＤＭ对聚甲醛（ＰＯＭ）的共混增韧生。结果表明，ＭＥＰＤＭ能明显改善ＰＯＭ与ＥＰＤＭ的相容性，使共混物分散相尺寸明显减少，分布更均匀，熔点和结晶度降低，缺口冲击强度提高。当ＰＯＭ／ＥＰＤＭ／ＭＥＰＤＭ（质量比）为８５／９／６时，共混物的缺口冲强度为１０．２ｋＪ／ｍ＾２。     

聚乙烯固相接枝马来酸酐的研究

研究了以过氧化苯甲酰（ＢＰＯ）为引发剂,二甲苯为界面剂,粉状聚乙烯（ＨＤＰＥ、ＬＬＤＰＥ）固相接枝马来酸酐（ＭＡＨ）的反应。讨论了反应温度、引发剂用量、单体用量和界面剂种类等对接枝反应的影响,并用红外光谱法证实了接枝反应。结果表明,ＰＥ固相接枝ＭＡＨ反应对温度敏感,随温度升高,接枝率提高;在一定范围内,接枝率随引发剂用量、单体用量和搅拌转速、界面剂用量的增加而提高;界面剂用量虽少,但能促进ＢＰＯ、ＭＡＨ在ＰＥ上的反应。通过接枝反应可得到接枝率为９％左右的ＰＥ－ｇ－ＭＡＨ产物和接枝率为１３％以上的ＬＬＤＰＥ－ｇ－ＭＡＨ产物     

DSC法对动态硫化PP／EPDM中PP—EPDM共交联结构的研究

根据共交联ＰＰ分子与正常ＰＰ分子在结晶与熔融特征及其对外因素响应上的差异,采用ＤＳＣ分析方法,研究了动态硫化ＰＰ／ＥＰＤＭ中ＰＰ－ＥＰＤＭ共交联结构。结果显示在动态硫化ＰＰ－ＥＰＤＭ的熔融ＤＳＣ曲线上的１５０℃曲线上约１５０℃处出现一新的熔融峰,改变结晶速率或ＤＳＣ测试程序,可发现形成这一新峰的化学结构具有强烈的结晶滞后性,而简单共混ＰＰ／ＥＰＤＭ的ＤＳＣ曲线上始终未出现类似新峰。结合化学反应理论     

中高压电力电缆用EPDM绝缘材料的开发

在１００份三元乙丙橡胶（ＥＰＤＭ）中加入ＺｎＯ５－８份，ＬＤＰＥ８－１０份，微晶石蜡４－７份，用硬脂酸锌片的煅烧陶土５０－６０份，Ａｌ（ＯＨ）３４０－５０份，硫化剂５－６份，防老剂１．２－１．６份，填料表面处理剂２－２．５份，制备了中高压电力电缆用ＥＰＤＭ绝缘材料。实验结果表明，成品电缆的物理机械性能可满足ＩＥＣ５０２－１９９４的要求。     

In Vitro and In Vivo Behaviour of In Complexes of TTHA, TTHA-Bis(Butylamide) and TTHA-Bis(Glucamide): Stability, Biodistribution and Excretion Studied by Gamma Imaging

Aiming at radiopharmaceutical application, (111)In(3+) complexes of the polyaminocarboxylates TTHA, TTHA-bis(butylamide) and TTHA-bis(glucamide) were investigated. The in vitro stability of (111)In(TTHA)(3-) and (111)In(TTHA-bis(butylamide)(-) was evaluated by measuring the exchange of (111)In(3+) from the complexes to transferrin and the results were compared with those for (111)In(DTPA)(2-). We also performed biodistribution studies of the three (111)In(3+) complexes by gamma-imaging in Wistar rats and by measuring the radioactivity in their organs. TTHA and its derivatives seem to have similar in vivo biodistribution with prevailing renal excretion.     

Electronic transport properties of In-doped ZnO nanobelts with different concentration

In this paper, zinc oxide (ZnO) nanobelts with five different indium (In) concentrations (1.98, 2.73, 3.33, 4.20, and 5.16 wt%) were prepared by simple vapor deposition with HAuCl(4) (1% solution) as catalyst. Detailed structural and compositional characterizations were performed by XRD, TEM, EDS, PL, and Raman spectroscopy. Moreover, the current-voltage (I-V) characteristics of In-doped ZnO nanobelts with different In concentrations were determined by nano-manipulation and measurement systems. The results show that the resistivity of these nanobelts decreases with increasing In concentration when the doping concentration of In is lower than 4.20%, but, on the contrary, when the In concentration is higher than 4.20% their resistivity increases. Also, all of the nanobelts keep ohmic contact very well. Simultaneously, the influence of electron beam irradiation (20 kV) on the nanobelts was studied, and it was found that electron beam irradiation can improve the conductivity of the nanobelts. Under the same voltage, the current increased gradually during irradiation until equilibrium was reached. The degree of influence of the irradiation on the resistivity of the nanobelts is the greatest when the In dopant concentration is 4.20%, which is suitable for making irradiation sensors.     

松香马来酰亚胺聚酯合成

松香与马来酐反应加合物的产率为７９％。在ＤＭＦ中加合物与氨基苯甲酸反应的产物，Ｎ－羧苯基松香马来酰亚胺的产率大于９０．４％。在Ｈ＿３ＢＯ＿３－ＺｎＯ催化下３种松香马来酰亚胺聚酯的产率为８０％，８０％，７２％。ＴＧＡ测定表明，它们的ＯＮＳＥＴ温度超过４９０℃。应用试验表明，添加１５％松香马来酰亚胺聚酯，不但提高不饱和聚酯固化膜的热稳定性能．而且保持不饱和聚酯膜的气干性能。     

Transient behavior of the oxidation of propylene over a modified silver oxide

The oxidation of propylene over a silver oxide containing sodium chloride and sodium hydrogensulfate has been studied by using a transient response method at temperatures ranging from 150 to 175°C. An overshoot behavior for the transient response of propylene oxide indicates the mechanism of Eley-Rideal type with a rapid desorption of propylene oxide and a slow regeneration of surface oxygen. The activation energy estimated at the transient state was 58.6 kJ/mol. A characteristic S-shape mode for the transient response of carbon dioxide reveals the presence of a stable intermediate (In). The (In) can produce equimolar amounts of H₂O and CO₂ by the reaction with oxygen without producing propylene oxide, indicating that the ratio of C:H in the structure of (In) is 1:2. The amount of (In) estimated under the steady state of reaction is a linear relation to the rate of CO₂ formation. The estimated apparent rate constant for the formation of CO₂ is in good agreement with that for (In) decomposition estimated from the transient response curves of (In) decomposition. From this agreement, it is concluded that the (In) is a reaction intermediate through which carbon dioxide and water are produced.     

Characterization of Mn species in mesoporous systems: An electrochemical study

Siliceous (MCM-41 type) and aluminophosphate (AlPO type) mesoporous materials have been synthesized trying to substitute the largest amount of Si and Al with Mn.

The MnMCM-41 and MnAlPO obtained samples were characterized from the structural viewpoint and successively they underwent electrochemical testing by means of cyclic voltammetries in aqueous electrolytes in order to evaluate the electrochemical activity of the transition metal. In this communication, we report the results obtained from the structural and electrochemical characterization of these samples. The samples show the expected mesoporous structure with hexagonal array. In both systems, Mn is electrochemically active. In MnMCM-41 the two Mn(IV)/Mn(III) and Mn(III)/Mn(II) processes can be detected, while in MnAlPO Mn(III), originally present, shows only the Mn(IV)/Mn(III) reaction.     

含高相对分子质量氟化聚硅氧烷链段的水性聚氨酯脲的制备与性能(英文)

以数均相对分子质量(n)较高(8 361～21 760)的α,ω-二羟基聚甲基(3,3,3-三氟丙基)硅氧烷(PTFPMS)、聚酯二元醇、二羟甲基丙酸、异佛尔酮二异氰酸酯和乙二胺为原料,制备了一系列贮存稳定性优良的大分子主链中含有少量(质量分数为5%)长PTFPMS链段的聚氨酯脲(PUU)水分散液,并对其性能进行了研究.结果表明,与未改性或用低相对分子质量(n 为798)PTFPMS改性的PUU水分散液相比,用高相对分子质量PTFPMS改性的PUU水分散液的粒径减小;含高相对分子质量PTFPMS链段的PUU水分散液成膜后,其表面疏水性和力学性能比纯PUU水分散液有很大程度的提高,而比含低相对分子质量(n 为798)的PTFPMS链段的PUU水分散液有一定程度的提高.     

Regenerative Therapies to Restore Interneuron Disturbances in Experimental Models of Encephalopathy of Prematurity

Encephalopathy of Prematurity (EoP) is a major cause of morbidity in (extreme) preterm neonates. Though the majority of EoP research has focused on failure of oligodendrocyte maturation as an underlying pathophysiological mechanism, recent pioneer work has identified developmental disturbances in inhibitory interneurons to contribute to EoP. Here we investigated interneuron abnormalities in two experimental models of EoP and explored the potential of two promising treatment strategies, namely intranasal mesenchymal stem cells (MSCs) or insulin-like growth factor I (IGF1), to restore interneuron development. In rats, fetal inflammation and postnatal hypoxia led to a transient increase in total cortical interneuron numbers, with a layer-specific deficit in parvalbumin (PV)+ interneurons. Additionally, a transient excess of total cortical cell density was observed, including excitatory neuron numbers. In the hippocampal cornu ammonis (CA) 1 region, long-term deficits in total interneuron numbers and PV+ subtype were observed. In mice subjected to postnatal hypoxia/ischemia and systemic inflammation, total numbers of cortical interneurons remained unaffected; however, subtype analysis revealed a global, transient reduction in PV+ cells and a long-lasting layer-specific increase in vasoactive intestinal polypeptide (VIP)+ cells. In the dentate gyrus, a long-lasting deficit of somatostatin (SST)+ cells was observed. Both intranasal MSC and IGF1 therapy restored the majority of interneuron abnormalities in EoP mice. In line with the histological findings, EoP mice displayed impaired social behavior, which was partly restored by the therapies. In conclusion, induction of experimental EoP is associated with model-specific disturbances in interneuron development. In addition, intranasal MSCs and IGF1 are promising therapeutic strategies to aid interneuron development after EoP.     

X‐ray photoelectron spectroscopy investigation of the interaction of U(VI) and Fe(III) with natural humic acid in aqueous solutions

Complexes of U(VI) and Fe(III) with natural humic acid (NHA) were studied by X‐ray photoelectron spectroscopy (XPS). It follows from the analysis of the uranium and iron concentrations at the surface and in the bulk of the humates that the reaction in solution is heterogeneous. The NHA reacts as a particle. In solutions containing either U(VI) or Fe(III), NHA reacts similar with Fe(III) and U(VI). However, in a mixed solution of Fe(III) and U(VI), NHA reacts predominantly with iron. In comparison to Fe(III) complexes, the complexes with U(VI) are formed mostly in the inner of the NHA particle. Therefore, the concentration ratio U/Fe as measured by XPS increases by powdering of the particles. Salts of Fe(III) can be used to inhibit the uranium migration in form of its soluble humates.     

Effect of immobilization of poly(γ-glutamic acid) on the biocompatibility of electrospun poly (L-lactide) mats

In this study, poly(L-lactide) (PLLA) non-woven mats were prepared by electrospinning technique, followed by treating with oxygen plasma and grafting with 3-aminopropyl triethoxysilane (APTES), then immersed in poly(γ-glutamic acid) (γ-PGA) solution to form a layer of γ-PGA on the surface. In so doing, hydrophobic PLLA would become highly hydrophilic. Through characterization of hydrophilicity and biocompatibility, the feasibility of these modified mats for wound dressing was evaluated. The results show that after the grafting of γ-PGA, the swelling ratio increased greatly from 7% for pristine PLLA mat to 321% for γ-PGA-grafted PLLA mat, and the contact angle decreased from 112° to 25°. In vitro cytocompatibility tests against L929 fibroblast show that γ-PGA-grafted PLLA was non-cytotoxic. In addition, the proliferation of fibroblasts was higher on γ-PGA-grafted PLLA than on pristine PLLA.