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Morphology-induced mechanical grafting in immiscible polymer blends.

机译：不混溶的聚合物共混物中的形态诱导机械接枝。

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Immiscible polymer blends are a class of composite materials in which morphology development is critical to the establishment of good mechanical properties since little or no chemical bonding occurs across the polymer domain interfaces. Morphology evolution was studied in several binary blend groups containing an amorphous polymer and a semi-crystalline polymer. Co-continuity development and the role of such morphologies in property development were examined with regard to defining structure-property relationships for selected mechanical properties. The degree to which these morphological structures affect molecular configurations, i.e. crystallinity and chain orientation, was also studied by thermal and spectroscopic analysis.; The effect of blend morphology on crystallinity development, studied via thermal analyses measurements, showed that crystallinity is suppressed for blends with co-continuous morphologies. Mechanical properties also depended on domain morphology and subtle differences in co-continuity generated by varied processing methods were reflected in interesting and revealing variations in certain mechanical properties.; Crystallinity suppression observations indicate that co-continuous morphologies are crucial to the establishment of an interlocked structure where molecular rearrangements are suppressed during crystallization owing to shear-induced orientation coupled with morphological hindrance. The enhanced continuity observations and moderately improved mechanical properties of certain blends processed with advanced extruder mixing elements was a major finding of this thesis. This process, which includes unusually high levels of elongational shear mixing is a novel approach to the improvement of mechanical properties in single screw extrusion.; Raman spectroscopic observations revealed an anomalous increase in the in-phase (1128 cm-1) and out-of-phase (1061 cm-1) stretching vibrational intensities of polyethylene molecules that normally arise from their crystalline conformations, but which in this study were found in low crystallinity co-continuous regions. This anomaly is indicative of an unusual orientation of the molecules in those compositions, one in which the simultaneous crystallinity reduction and enhancement of the crystalline Raman intensities has been used to establish the mechanics of the grafting process in co-continuous morphologies of immiscible polymer blends.; Advances in the interpretation of image analysis data developed as part of this thesis to quantify developing continuity in immiscible blends has enhanced the scientific understanding and engineering design of these blends.
机译：不混溶的聚合物共混物是一类复合材料，其中形态的形成对于建立良好的机械性能至关重要，因为在整个聚合物域界面上几乎没有化学键发生或没有化学键发生。在包含无定形聚合物和半结晶聚合物的几个二元共混物组中研究了形态演变。就定义机械特性的结构-特性关系而言，研究了共连续性发展以及这种形态在特性发展中的作用。还通过热和光谱分析研究了这些形态结构影响分子构型的程度，即结晶度和链取向。通过热分析测量研究了共混物形态对结晶度发展的影响，结果表明具有共连续形态的共混物的结晶度受到抑制。机械性能还取决于磁畴的形态，通过变化的加工方法所产生的共连续性的细微差别反映在某些机械性能的有趣和显着变化中。结晶度抑制的观察结果表明，共连续形态对于建立互锁结构至关重要，在互锁结构中，由于剪切诱导的取向和形态学障碍，在结晶过程中抑制了分子​​重排。用先进的挤出机混合元件加工的某些共混物，其连续性观察值得到增强，机械性能得到适度改善，这是本论文的主要发现。这种包括异常高水平的拉伸剪切混合的过程是一种改善单螺杆挤出机械性能的新颖方法。拉曼光谱观察发现，聚乙烯分子的同相（1128 cm-1）和异相（1061 cm-1）拉伸振动强度异常增加，通常是由于它们的结晶构象引起的，但在本研究中是在低结晶度的连续区域发现。这种异常现象表明了这些组合物中分子的不同寻常的取向，其中同时结晶度降低和结晶拉曼强度提高已被用来建立不混溶聚合物共混物共连续形态的接枝过程机理。 ;作为定量分析不混溶共混物发展连续性的本论文一部分而开发的图像分析数据的解释进展，增强了对这些共混物的科学认识和工程设计。

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