The use of multi materials within a single composite structure provides many advantages, including component cost reduction, the ability to manufacture complex designs and greater potential for part recyclability. However, these multi materials can often have very different properties and surface chemistries, and can be challenging to join when using adhesives. This research explores a new processing concept of surface treatment that promotes adhesion between dissimilar composite materials by introducing covalent bonding between substrate and adhesive. An epoxy amine resin is dissolved in a solvent to functionalise the surface of a polyamide 66 glass fibre composite prior to adhesive bonding to a carbon fibre epoxy composite. The effect of surface treatment time, temperature and solvent polarity is investigated using Fourier Transform Infra-Red (FTIR) spectroscopy, lap shear adhesion and scanning electron microscopy (SEM). Lap shear strength of some solvent treated samples is more than 3 times higher than the untreated samples, while the extent of epoxide cure correlates strongly with adhesive strength. Solvent polarity had little or no effect on the bonding strength providing flexibility in solvent selection.

在单个复合结构内使用多种材料可提供许多优势，包括降低组件成本，制造复杂设计的能力以及更大的零件回收利用潜力。然而，这些多种材料通常可能具有非常不同的特性和表面化学性质，并且在使用粘合剂时加入时可能存在挑战。这项研究探索了一种新的表面处理工艺概念，即通过在基材和粘合剂之间引入共价键来促进异种复合材料之间的粘合。在粘合剂粘结到碳纤维环氧复合材料上之前，将环氧胺树脂溶解在溶剂中以官能化聚酰胺66玻璃纤维复合材料的表面。表面处理时间的影响，使用傅立叶变换红外（FTIR）光谱，搭接剪切粘合力和扫描电子显微镜（SEM）研究了温度和溶剂极性。某些溶剂处理过的样品的弯曲剪切强度比未处理过的样品高3倍以上，而环氧固化的程度与粘合强度密切相关。溶剂极性对粘合强度几乎没有影响，甚至没有影响，提供了溶剂选择的灵活性。