SBIR Phase I: Interface Control in Vapor-Grown Carbon Fiber/Polymer Composites

这个小企业创新研究第一阶段项目旨在了解和修改表面状态、表面化学，并开发用于复合材料界面控制的气相生长碳纤维的浆料。与脆性基复合材料相比，聚合物基复合材料通常需要高度的纤维-基体粘附，以提供良好的复合强度和韧性。大多数商用增强纤维，包括碳纤维和玻璃纤维，在制造过程中或制造后都经过各种表面处理和施胶处理，以增加与基体聚合物的相容性和粘合性。一种新型碳纤维已经开发出来，并正在中试规模生产。这种蒸汽生长碳纤维（VGCF）具有高石墨纤维增强的前景，其成本明显低于其他碳纤维。然而，由于这种纤维的高石墨化，纤维表面通常不反应，不会与聚合物基体结合。因此，将评估各种处理方法在促进聚合物基复合材料中纤维/基体结合方面的效果。具体来说，不同程度的表面氧化将影响到纤维，然后应用商业浆料。表面化学将被量化，并通过复合材料测试进行验证。作为一种低成本的纤维，VGCF可以用作许多弹性体和聚合物基体的复合增强材料。低纤维基质粘附性问题的解决将允许开发至少一种商业上可行的材料，用于汽车部件，需要EMI屏蔽的材料，以及需要小直径纤维的创新复合材料。

This Small Business Innovation Research Phase I project is aimed at developing an understanding of and modifications to the surface state, surface chemistry, and development of sizings for vapor-grown carbon fibers for interface control in composites. In contrast to brittle matrix composites, polymer matrix composites generally require a high degree of fiber-matrix adhesion in order to provide good composite strength and toughness. The majority of commercial reinforcing fibers, both carbon and glass, are treated during or after manufacture with various surface treatments as well as a sizing to increase compatibility with and bonding to the matrix polymer. A new class of carbon fiber has been developed and is being produced in pilot scale quantities. This vapor-grown carbon fiber (VGCF) holds the promise of a highly graphitic fiber reinforcement at costs significantly lower than other carbon fibers. However, due to the high graphitization of this fiber, the fiber surface is generally unreactive and will not bond with polymer matrices. Thus, various treatments will be evaluated for their effect in enabling fiber/matrix bonding in polymer matrix composites. Specifically, various degrees of surface oxidation will be effected onto the fibers followed by application of commercial sizings. The surface chemistry will be quantified and also verified from composite testing. As a low cost fiber, VGCF can potentially be used as a composite reinforcement for many elastomeric and polymeric matrices. The solution of the problem of low fiber-matrix adhesion will allow for the development of, at least one, commercially viable material for use in automotive parts, materials requiring EMI shielding, and innovative composites requiring small diameter fibers.