表面改性赤泥协同阻燃聚丙烯的研究

为了提高聚丙烯(PP)材料的阻燃性能,用硬脂酸对赤泥(RM)进行表面改性后添加到聚丙烯中,制备出PP/表面改性赤泥(MRM)复合材料,并研究了将表面改性后的赤泥与微胶囊红磷(MRP)、氢氧化镁(MH)、氢氧化铝(ATH)、三聚氰胺(MEL)、聚磷酸铵(APP)、氧化锑(Sb_2O_3)、氧化锌(ZnO)进行复配的效果。结果表明,表面改性后的赤泥(MRM)具有更优的加工性能,与PP基体间的相容性更好;在PP基体中添加50份MRM所制得的PP/MRM复合材料的熔融指数比PP/RM复合材料高20.08 g/10 min;MRM与MRP、MH、ATH、MEL、APP、Sb_2O_3阻燃剂进行复配后可以较好地改善PP复合材料的阻燃性能;当PP∶MRM∶MRP∶(MH+ATH)∶MEL∶APP∶Sb_2O_3为100∶95∶10∶25∶20∶20∶20时,PP复合材料的阻燃性能最佳,其氧指数和垂直燃烧等级分别达到29.1%和V-0级。     

新型高分子型阻燃抗静电剂的合成及应用

以氯磷酸二乙酯,丙烯酸羟乙酯合成了阻燃单体(FR);以丙烯酰氯,辛基酚聚氧乙烯醚合成了抗静电单体(AS);以FR/AS/MMA为共聚合单体,用自由基聚合方法制备了阻燃抗静电剂,并与聚丙烯(PP)复合制备了含AMF162的PP复合材料．采用傅立叶变换红外光谱(FTIR)、热失重分析法(TG)、氧指数测定、电阻率测定以及抗冲击强度测定等对PP复合材料进行了表征和分析,探讨了阻燃抗静电剂的用量对PP复合材料热稳定性、阻燃和抗静电性能以及冲击强度的影响．结果表明,阻燃抗静电剂的含量为20%时,PP复合材料的氧指数(LOI)达到20.8%;材料的表面电阻率到达1012级,比改性前下降了4个数量级,阻燃抗静电剂的加入明显改善了PP材料的阻燃抗静电性能;阻燃抗静电剂的添加量不超过15%时可提高PP材料的冲击强度,添加量为20%时PP材料的冲击强度有所下降,但影响不大．     

PP/ABS合金的制备及不同阻燃剂对其性能的影响

选用过氧化二异丙苯(DCP)作为交联剂,三烯丙基异氰脲酸酯(TAIC)作为助交联剂,在密炼机里熔融共混制备PP/ABS合金.对制得的产物进行红外光谱、扫描电镜测试.结果表明最佳的添加量为DCP 0.2%(质量分数),TAIC4%(质量分数);在制得的PP/ABS合金的基础上,先单独添加阻燃剂N,N-四溴邻苯二甲酰亚胺(BT-93W),然后进行BT-93W和阻燃增效剂2,3-二甲基-2,3-二苯基丁烷(DMDPB)复合添加,对制得的两种复合材料进行力学性能、极限氧指数、垂直燃烧实验测试.结果表明:阻燃协效剂DMDPB复合BT-93W使用时,在不影响阻燃性能的情况下,能大幅度减少BT-93W的用量,减少其对材料力学和加工性能的影响.     

不同配比的水-乙醇中密胺树脂包覆聚磷酸铵及其阻燃性能

采用原位聚合法制备密胺树脂包覆聚磷酸铵(MFAPP),研究了不同体积比的水-乙醇混合溶剂对包覆效果的影响,并考察不同包覆产物对聚丙烯(PP)阻燃性能的影响。采用溶解度实验、红外光谱(FT-IR)、热重分析(TG)、扫描电镜(SEM)分别考察聚磷酸铵(APP)包覆前后溶解度、官能团、热稳定性以及表面形态的变化;通过氧指数、耐水性实验考察了APP包覆前后对PP阻燃性能的影响。实验结果表明:与APP相比,以水-乙醇为混合溶剂制备的MFAPP,其耐水性得到明显改善,在水中的溶解度明显下降;红外结果显示MFAPP中产生了三聚氰胺新的官能团。随着溶剂中水的比例增加,MFAPP中壳材密胺树脂含量增加,水和乙醇体积比约为1∶1时,APP包覆效果最好,耐水性提高最大。PP中MFAPP的w=30%时,复合材料阻燃性能最佳,氧指数达到29.5%。     

聚丙烯/凹凸棒土复合材料的制备与性能研究

本文以聚丙烯(PP)为基体,分别以凹凸棒土(ATB)有机改性凹凸棒土(ATBf)为无机粒子填充剂,通过熔融共混的方法制备了PP/ATB、PP/ATBf复合材料。对改性ATBf进行了TEM结构表征并讨论和比较了ATB、改性ATBf对PP/ATB、PP/ATBf复合材料的机械性能、流动性能、结晶行为的影响。结果表明PP-g-MAH均匀地吸附在ATB表面,达到了表面改性的效果测试,ATB和ATBf的加入都能使复合材料的拉伸性能和冲击性能大大提高:在ATB含量为1wt%时,PP/AT复合材料的拉伸强度达34MPa,冲击强度达到了2.8kJ/m2;当ATBf的含量达到2wt%时,PP/ATBf复合材料的拉伸强度达到了37.5MPa,冲击强度明达到了3.3kJ/m2。ATB、ATBf的加入,对基材起到了明显的成核作用,降低了复合体系对对结晶温度的依赖性,提高了结晶速率。ATB的加入对复合材料熔融指数的增加不大,而ATBf的加入对提高了复合材料流动性能。     

纳米CaCO3改性聚丙烯力学性能和微观结构的研究

通过混合、熔融挤出,把纳米CaCO3填充到聚丙烯PP基体中去,制得高强度低成本的PP改性复合材料。对该复合材料进行了力学性能测试和微观结构的观察,并对纳米CaCO3改性PP的增韧机理进行了讨论。实验结果表明,纳米CaCO3填充PP用量在12份时,对PP复合材料有明显的增韧增强作用,而且可有效地降低原料成本18%～25%。     

新型磷-硅阻燃剂和聚磷酸铵对PP的协效阻燃作用

研究了一种含磷硅高分子阻燃剂(EMPZR)和聚磷酸铵(APP)对聚丙烯(PP)阻燃及力学性能的影响。当APP/EMPZR=20/15(质量比)时,所制得的阻燃PP复合材料氧指数达到28.0%,垂直燃烧达到UL-94 V-2级;与纯PP相比,拉伸、弯曲和冲击强度都没有下降;热失重分析(TGA)测试表明,阻燃PP材料在600℃时的残炭量为21.20%(质量分数),成炭率显著提高;扫描电镜(SEM)对残炭形貌的表征以及氧指数测试前后的阻燃PP材料的红外图谱分析证实了EMPZR和APP在PP中良好的协效阻燃作用。     

纳米硼酸锌4ZnO·B2O3·H2O/酚醛树脂复合材料的合成及其阻燃性能研究

为了进一步提高酚醛树脂的阻燃性能,在酚醛树脂中填充纳米硼酸锌4ZnO·B2O3·H2O粒子对其进行改性.实验中采用苯酚、甲醛和自制改性纳米硼酸锌为原料通过原位合成法制备了纳米硼酸锌4ZnO·B2O3·H2O/酚醛树脂复合材料,通过红外光谱(FT-IR)、扫描电子显微镜(FESEM)、热重-差热分析(TG-DTA)和氧指数测定仪(LOI)对复合材料进行表征和测试.结果表明,添加纳米硼酸锌4ZnO·B2O3·H2O后,酚醛树脂的热稳定性有了明显提高,特别是当添加量为7%时,复合材料氧指数达到最大值46.3,酚醛树脂的阻燃性能显著提高.     

环保型无机阻燃剂的表面改性及在PP中的应用研究

实验研究了改性剂用量、改性时间和改性温度对氢氧化镁改性效果的影响，并用活化指数和吸油值进行表征分析，从而确定最佳改性工艺条件，并将改性前后的氢氧化镁粉体添加到聚丙烯（PP）中，再对样条进行SEM实验，对阻燃性能和机械力学性能进行考察.实验结果表明，氢氧化镁阻燃剂的最佳改性工艺条件为：改性剂用量为4%、改性温度为80 ℃、改性时间为40 min.SEM表明，相对于未改性的氢氧化镁来说，改性后的氢氧化镁能均匀地分散在PP中，相容性较好.性能测试表明，加入了改性后的氢氧化镁阻燃剂的PP的氧指数有明显提高，由纯基体的19.0%到29.6%，提高了10.6%，且可达到V-1阻燃级，机械力学性能方面相对于纯PP体系有所下降，但和未改性的比较有所增强.     

微胶囊化改性氢氧化镁及其在低密度聚乙烯中的阻燃性能研究

采用一步法合成了三聚氰胺树脂和脲醛树脂。分别对氢氧化镁阻燃剂进行微胶囊化改性,通过对其FTIR、SEM、TEM、TG DSC、XRD,以及添加至高聚物中后进行复合材料常规力学性能测试和极限氧指数（LOI）的测定,研究微胶囊化改性超细氢氧化镁的改性效果。结果表明,三聚氰胺树脂和脲醛树脂被成功包覆在氢氧化镁表面,并且改性后氢氧化镁热稳定性良好,粉体与聚合物基体之间的界面粘结性得到提高,与未改性氢氧化镁相比机械性能有较大提高,其极限氧指数较低密度聚乙烯有很大提升。其中,以反应温度70 ℃、包覆量15%的微胶囊化改性效果最好。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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