| Throughout the course of this research, the effects of various methods of promoting adhesion between polymers and metals were investigated. The potential application of this research is in an underwater cable connector assembly, in which a plastic jacket is connected to both metal and more plastic.; The plastic materials used in this study included LDPE, m-LLDPE, and HDPE. The metal of choice was stainless steel, grade 303. Steel inserts were cut into specimens to produce an area in the shape of a lap joint, and plastic inserts were injection molded into the shape of half an ASTM type 1 tensile bar.{09}The adhesion promotion methods chosen in this study included plasma treatment of both the plastic and metal inserts, and mechanical interlocking of the plastic into the metal inserts. Once all inserts were prepared, they were placed into the mold cavity and each of the types of plastic material was over-molded onto them, causing a lap joint to be created. All samples were then subjected to a lap shear tensile test, which is similar to a standard ASTM D 638 tensile test. Tensile lap shear strength, percent elongation and shear modulus were then calculated.; The results of this study showed that using plasma treatment on plastic inserts actually decreased the adhesive strength of the material, while using plasma treatment on the metal inserts only slightly increased the adhesive strength. The results also showed that the use of mechanical interlocking was far more effective than plasma treatment when using metal inserts. Finally, the optimal plastic material for adhesion in this study was not apparent because this determination relied heavily on the environment and the specified use of the joint. |
