γ射线辐照HDPE/微晶白云母填充体系力学性能的研究

采用γ射线辐照在DPE分子链上引入含氧极性基团，增加了HDPE与微晶白云母的界面相容性，研究了界面增容剂对γ－HDPE／微晶白云母体系力学性能的影响，通过SEM对该体系的形态结构进行了研究，探讨了界面增容剂的作用；研究了粒径对γ－HDPE／微晶白云母填充体系力学性能的影响，结果表明，通过γ射张辐照增容，该体系的强度和韧性明显提高。粒径5000mesh，在体系中含量为40％（质量）的微晶白云母可使该体系的屈服强度和缺口冲击强度从HDPE的24．2MPa和210J/m分别提高到32．8MPa和388J／m。     

电子束辐照对HDPE/PA6共混体系的影响

通过电子束辐照的方法，在高密度聚乙烯（HDPE）分子链上引入含氧极性基团，增加了HDPE分子的极性，改善了HDPE与PA6的界面相容性，本文通过FT－IR，SEM，接触角、DSC等方法对电子束辐照HDPE／PA6体系的界面相互作用及其对共混体系结构与性能的影响进行了研究，结果表明，HDPE经电子束辐照后，在其分子链上引入了含氧极性基团，提高了HDPE的极性，增加了表面自由能，从而改善了其与PA6界面相容性，随着辐照剂量的增大，PA6分散相的粒径变小，在HDPE基体中的分散更均匀。     

HDPE紫外辐照改性及其与PVA共混体系的力学性能

研究了紫外辐照对高密度聚乙烯（HDPE）结构与性能以及HDPE/聚乙烯醇（PVA）短纤维共混体系力学性能的影响。结果表明,在空气中通过紫外辐照可在HDPE分子链上引入C=0、C-0含氧基因,使HDPE分子量下降、熔点降低、结晶度增大并产生凝胶。以辐照HDPE为增容剂,增强了HDPE与PVA相界面的相互作用,共混物的拉伸屈服强度和缺口冲击强度得到提高。     

Al／Al2O3多层膜的表面和界面的分析研究

用热蒸发沉积和自然氧化及加热法制备纳米量级的Al/Al2O3薄膜和多层膜。用X射线光电子谱仪（XPS）和透射电镜（TEM）对样品进行检测。XPS实验说明自然氧化的Al2O3膜层厚在2－5nm。Al/Al2O3薄膜及多层膜的O与Al的原子浓度比为1.43-1.85。Ar离子刻蚀的XPS实验结果（刻蚀速率为0.09nm/s)说明：2个对层的Al/Al2O3多层膜截面样品具有周期性结构。TEM观察到了5个对层的Al/Al2O3多层膜的层状态结构，其周期为4nm。由此说明，热蒸发及自然氧化法是制备纳米量级的Al/Al2O3多层膜的有效方法。     

紫外辐照官能化HDPE及复合材料力学性能

研究了不同紫外光强下辐照的HDPE结构和性能变化。在相同的辐照环境温度和辐照时间下,引入HDPE分子链的C—O、C O和C ( O) O等含氧基团数量随紫外光强提高而增加,提高紫外光强加快了HDPE的官能化,但辐照HDPE中的凝胶含量也有所增加。紫外辐照不影响HDPE的晶型和晶胞参数,但会引起它的熔融温度下降、结晶度提高以及亲水性的改善,其变化幅度随紫外光强提高而加大。辐照HDPE作为增容剂加到HDPE/PVA中,提高了复合材料的力学性能。较高紫外光强下辐照的HDPE表现出更好的增容作用。      

微波辐照对iPP在Al/iPP/Al界面层残余应力的影响

采用薄膜X射线衍射(TF-XRD)方法研究了微波辐照后Al／iPP／Al夹心材料中iPP界面宏观残余应力,微观应力和点阵静畸变应力的变化,结果表明,微波辐照后iPP的宏观残余张应力减小。垂直于[300]晶面(β晶形)的晶粒尺寸增大,β晶形生长趋于完善,晶格微观畸变减小,微观应力减小,α晶形微观应力增大。β晶形的点阵静畸变应力和应力能量小于α晶形,这是引起α→β晶形转变的主要原因。     

Al／Al2O3多层膜的表面分析与电性能的研究

用热蒸发沉积和自然氧化及加热法制备纳米量级的Al/Al2O3薄膜和多层膜。本用X射线光电子能谱（XPS）和紫外光电子能谱（UPS）对样品进行价带能谱的检测与分析。获得的Al/Al2O3多层膜价带的XPS光电子谱谱形基本相似；通过对Al/Al2O3三层膜在不同极角的UPS谱线的检测，得到其Ei-(Ki∥）关系曲线，此外，测定了低温的I－U特性，发现纳米量级的Al/Al2O3薄膜具有负阻特性。     

Al/Al2O3陶瓷接合基板的制备及性能研究

在675－825℃、氮气气氛下，使用石墨模具压铸的方法制备出Al/Al2O3电子陶瓷基板，利用力学拉伸试验机测试了Al和Al2O3的结合强度，界面抗拉强度＞15．94MPa，使用金相显微镜、SEM等微观分析仪器研究了其界面的微观结构。     

退火工艺对Al/Mg/Al复合板界面结合与阻尼性能的影响

研究了Al/Mg/Al三明治结构复合板的退火热处理工艺,探讨了退火温度、时间对复合界面和阻尼性能的影响。结果表明:退火使得Mg层中的孪晶及变形组织消失,晶粒明显长大,且可以促进Al-Mg界面原子的相互扩散。随着退火温度的升高,界面效应对复合板的阻尼性能影响由不利转变为有利,在250℃下随着退火时间的延长,复合板的阻尼性能有一定的提高。综合复合板的组织与性能要求,得到Al/Mg/Al复合板的最佳退火工艺为250℃×2h,在应变振幅为5×10~(-4)下复合板的阻尼值Q~(-1)达0.045。     

反应增容HDPE基木塑复合材料及增容机制

使用密炼机对木纤维（WF）进行酯化改性,将改性木纤维（EWF）与高密度聚乙烯（HDPE）、过氧化二异丙苯（DCP）混合,再用双螺杆挤出机反应挤出制备EWF/HDPE复合材料。使用FTIR、力学性能测试、SEM、广角X射线衍射（WAXD）和示差扫描量热－热重同步热分析（TG-DSC）研究了EWF/HDPE复合材料的微观结构和物理力学性能。结果表明,在密炼机中对WF的酯化改性成功地在WF表面引入了酯基;反应挤出所得EWF/HDPE复合材料与无增容WF/HDPE复合材料相比,其冲击和拉伸强度最大分别提高了112%和36%,EWF与HDPE两相之间的界面粘合明显改善,HDPE的晶粒尺寸有所增加,结晶度也有较大提高,但热稳定性有少许下降。EWF/HDPE复合材料力学性能的提高主要归因于反应挤出的增容作用,而非基体HDPE结晶结构的变化。     

紫外线辐照HDPE与尼龙－6共混材料结构与力学性能的研究

研究了紫外线辐照ＨＤＰＥ与ＰＡ６共混材料的微观形态、结晶结构、熔融行为及力学性能。ＳＥＭ、ＷＡＸＤ、ＤＳＣ结果表明，随紫外线辐照时间的增加，共混物中ＰＡ６的粒径减小，与基体作用加强，ＨＤＰＥ晶面间距增大，熔点、结晶度降低，熔程变窄。力学性能测试结果表明，紫外线辐照能明显提高共混材料（ｕＨＤＰＥ／ＰＡ６：９０／１０）的拉伸强度、断裂伸长率、拉伸断裂能和冲击强度。当辐照时间超过１４４ｈ由于ＨＤＰＥ热稳定性明显降低，共混过程中ＨＤＰＥ热降解严重，共混物的韧性突降。     

紫外线辐照HDPE与尼龙－6相容性的研究

采用ＩＲ、ＳＥＭ、ＤＳＣ和拉伸应力－应变曲线研究了紫外线辐照ＨＤＰＥ／ＰＡ６的相容性，结果表明，随紫外线辐照时间的增长，ＨＤＰＥ分子链上引入Ｃ＝Ｏ－Ｃ－Ｏ－等极性基团明显增加；ＰＡ６的粒径减小，与基体间界面作用加强；两组分玻璃化温度差（Ｔ_（ｇ，ＰＡ６）－Ｔ_（ｇ，ＨＤＰＥ））减小；共混物拉伸应力－应变曲线上出现屈服点及拉伸冷流塑性形变。当辐照时间达１４４ｈ后，由于ＨＤＰＥ热稳定性明显变差，共混物韧性突降，拉伸应力－应变曲线上未出现屈服点。     

Structural analysis of nanocomposites based on HDPE/EPDM blends

Intercalated and exfoliated nanocomposites based on HDPE and EPDM blends with an organoclay have been obtained through the addition of EPDM-g-MA as a compatibilizer. The combined effect of clay and EPDM-g-MA on the rheological behaviour is very noticeable with a sensible increase in viscosity which suggests the formation of a structural net of percolation induced by the presence of intercalated and exfoliated silicate layer. As deduced from rheological studies, a morphology based on nanostructured micro-domains dispersed in HDPE continuous phase is proposed for EPDM/HDPE blend nanocomposites. XRD and SEM analysis suggest that two different transport phenomena take simultaneously place during the intercalation process in the melt. One due to diffusion of HDPE chains into the tactoid and the other to diffusion of EPDM-g-MA into the silicate galleries.     

HIPS/HDPE共混物的动态黏弹行为与相形态

采用动态流变测试和扫描电子显微镜技术,考察高抗冲聚苯乙烯(HIPS)/高密度聚乙烯(HDPE)共混物的动态黏弹行为与相形态,对比1%(质量分数,下同)的纳米和微米CaCO_3对HIPS/HDPE(30/70)不相容共混物的增容效果。结果表明:当HDPE小于30%时,HIPS/HDPE共混物在低频区的复数黏度和储存模量均显示出明显的正偏差,而当HDPE大于30%时,则呈现负偏差;前者与HDPE和PB粒子间的相互作用相关,而后者归因于HDPE基体与PS分散相之间较弱的界面相互作用。当HIPS为基体时,HDPE分散相粒子呈现较宽的尺寸分布;而当HDPE为基体时,PS分散相呈现双模尺寸分布,对应于两种不同类型的PS分散相粒子的存在。1%的纳米CaCO_3对HIPS/HDPE(30/70)不相容共混体系起到了一定的增容效果,CaCO_3纳米粒子主要位于HIPS/HDPE相界面以及HDPE连续相内;而微米CaCO_3对该共混体系仅起到了增黏而非增容作用,CaCO_3微米粒子仅位于HDPE连续相内。     

Tensile dilatometry of injection-moulded HDPE/PA6 blends

In order to understand the mechanism of deformation of injection-moulded HDPE/PA6 (25 vol% /75 vol%) blends both with and without compatibilizer, the volume change has been monitored using tensile dilatometry. Dog-bone specimens were either directly moulded or cut from rectangular plaques. Both neat materials and their blends were tested. For the directly moulded dog-bone specimen, a pure shear yielding mechanism was observed for all materials tested, i.e. PA6, HDPE, and their blends in the same proportion as above. In the case of a deformable minor phase (HDPE), the dispersed phase appeared to bear its share of stress and the flow-induced orientation mimics the effect of interfacial modification. This was not the case of a rigid minor phase (glass beads) at the same concentration; the effect of surface treatment changed the mechanism of deformation from mixed mode cavitation shear yielding (45%) to almost pure shear yielding (85%). Machined specimens made of neat PA6 and HDPE deformed through pure shear yielding. The addition of 25 vol% HDPE to PA6 resulted in a mixed mode cavitation (55%)/shear yielding mechanism of deformation in the transverse direction, while in the longitudinal case, the mechanism which prevailed was almost pure shear yielding (80%). This can be attributed to the flow-induced orientation as above. When adding 10% (based on the weight of the dispersed phase) of an ionomer as a compatibilizer, the blend deformed via shear yielding (85%) and in the longitudinal direction both compatibilized and non-compatibilized blends display similar behaviour. Varying the specimen thickness by changing the mould cavity, led to a significant variation in the dilatational behaviour. Dilatometric behaviour is shown to be closely related to the morphology generated as a result of flow-induced orientation. The skin/core ratio, which is an indication of the proportion of the oriented dispersed phase to the non-oriented one, plays a key role in influencing the mechanism of deformation involved.     

HDPE的紫外辐照官能化研究

通过FT-IR、凝胶分析、水接触角和力学性能测定,研究了空气中不同环境温度下紫外辐照官能化HDPE的结构变化、亲水性和紫外辐照官能化HDPE对HDPE／PVA共混体系的增容作用。在相同的紫外辐照时间下,随环境温度提高,引入HDPE分子链的C=O和C--O含氧基团的含量增加,其HDPE的亲水性变好,但它的凝胶含量也有所增加。与HDPE／PVA体系相比,经过紫外辐照官能化HDPE增容的HDPE／PVA体系的拉伸强度和缺口冲击强度均得到提高。     

HDPE/E-TMB共混物和HDPE/弹性体共混物的脆韧转变和断面形态

用材料力学性能测试方法和扫描电镜研究了HDPE/E-TMB共混物和HDPE/弹性体共混物的脆韧转变行为和冲击断面形态。结果表明,HDPE/E-TMB共混物的脆韧转变可在弹性体含量较低的情况下发生;弹性体含量相同时,HDPE/E-TMB共混物有更高的冲击强度和拉伸屈服应力;冲击强度相同时,HDPE/E-TMB共混物有更高的拉伸屈服应力和弯曲弹性模量。弹性体含量为8%的两种共混物的冲击断面形态属于不同的断裂机理,这种机理的不同揭示了HDPE/E-TMB共混物具有特殊的结构特征。     

Thermal and mechanical properties of HDPE/ionomer blends

The thermal behavior, tensile and tear strength of blends containing high density polyethylene (HDPE) and a sodium neutralized ethylene-methacrylic acid copolymer ionomer have been studied. It was found that each HDPE/ionomer blend had two well-separated melting peaks and two crystallization peaks, which indicates that the components of such a blend are immiscible with each other. The tensile behavior of the ionomer showed severe strainhardening just above the yield point, which leads to a lower elongation at break and a higher tensile strength than HDPE, possibly due to a network-like structure formation of ionic aggregates. The tensile properties of HDPE/ionomer blends were generally inferior to those of the pure components. Furthermore, the tensile properties exhibited severe negative deviation from linear additivity of properties, which is characteristic of incompatible blends. The negative deviation was also observed for tear strength of HDPE/ionomer blends. Observation of tear fracture surfaces of the blends showed fibrillar structure when ionomer content was relatively low. However, for the blends of higher ionomer composition much less fibrillation on the fracture surface was observed, which yields a higher value of tear energy. This is attributed to a network-like structure of the ionomer continuous phase of the blends.