Damp Heat Aging Performance of Hot-melt Adhesive for Heat Shrinkable Sleeve

Based on GB/T 2792-1 998 and GB/T 7124-2008, influence of damp heat aging on peel strength and lap shear strength of hot-melt adhesive for two kind of heat shrinkable sleeves is researched.Results show that peel strength and lap shear strength of hot-melt adhesive for two kinds of heat shrinkable sleeves on the steel with epoxy primer and PE coating of trunk pipeline are decreased with the increase of aging time,and especially the peel strength is greatly reduced at ambient temperature.At high temperature, influence of peel strength and lap shear strength of the adhesives on damp heat accelerated aging is slight.About laboratory test standard on heat shrinkable sleeve, the necessity to supplement the requirements in the testing of long-term adhesive performance for heat-melt adhesive and shear performance of structure for "heat-melt adhesive/trunk pipeline PE coating" is described.The reason for performance degradation of heat-melt adhesive is analyzed.For the ingredient of heat-melt adhesive, improvement suggestion in controlling the matching between polar component and non-polar component, avoiding small molecules component, widening the distribution of molecular weight for each component etc.are presented.