A Multi-Scale Approach for Understanding the Role of the Interphase in Polymer Matrix Composites

研究的重点是多尺度(分子-纳米-微米)的界面相及其与聚合物基复合材料(PMC)性能的关系。这项研究的第一个目标是在聚合物固化过程中对相间区域的化学成分进行现场实时监测。第二个目标是测量由于硅烷偶联剂表面处理而产生的界面相的尺寸和力学性能。第三个目标是对模型PMC系统的微观力学性能进行测量。为了达到研究目标，需要完成几项任务。第一项任务将包括使用一种新的傅里叶变换红外光纤传感器系统对模型聚合物进行现场反应监测，该系统可以直接监测相间化学。实验将在未经改性的玻璃纤维上使用聚合物/固化剂混合物，然后在高温下聚合固化作为时间的函数。接下来，将对玻璃纤维进行硅烷偶联剂表面处理，并同时测定有机功能反应性和固化剂/聚合物反应性。研究的第二个任务是表面处理和聚合物固化后的纳米力学性能表征。原子力显微镜和纳米压痕将用来表征界面区。这些结果将与第一个任务的现场红外数据相关联，特别是官能团反应性和聚合物固化对所得相间性质的作用。第三项任务将通过使用微粘结测试方法来测量模型PMC的微观力学行为。在这部分研究中获得的结果将与前面提到的两项任务相关联。

The focus of the research is a multi-scale(molecular-nanometer-micrometer) investigation of the interphase and itsrelationship to polymer matrix composite (PMC) performance. The firstobjective of the research is to monitor the chemistry of the interphaseregion in situ, and in real-time during the polymer curing cycle. Thesecond objective is to measure the size and the mechanical properties of theinterphases that result as a function of silane coupling agent surfacetreatments. The third objective is the measurement of the micromechanicalperformance of a model PMC system. Several tasks are involved to meet the research objectives. Thefirst task will involve in situ reaction monitoring of a model polymer usinga novel Fourier transform infrared fiber optic sensor system which allowsdirect monitoring of interphase chemistry. Experiments will be performedusing polymer/curing agent mixtures on unmodified glass fibers, and polymercuring followed as a function of time at elevated temperature. Next, silanecoupling agent surface treatments will be performed on the glass fibers andthe organofunctional reactivity determined simultaneously with curingagent/polymer reactivity. The second task in the proposed research will be the nano-mechanicalproperty characterization after surface treatment and polymer curing.Atomic force microscopy and nanoindentation will be used to characterize theinterphase region. These results will be correlated with the in situinfrared data from the first task, in particular, the role oforganofunctional reactivity and polymer curing on the resultant interphaseproperties. The third task will involve measurement of the micromechanicalbehavior of the model PMC through the use of the microbond test method.Results obtained during this portion of the research will be correlated withthe first two tasks mentioned above.