Tackifiers tend to have low molecular weight, and glass transition and softening temperature above room temperature, providing them with suitable viscoelastic properties. Tackifiers frequently represent most of both weight percentage and cost of hot melt adhesives and pressure-sensitive adhesives. In hot melt adhesives they can comprise up to about 40% of total mass.[2]
Tackifiers are usually resins (e.g. rosins and their derivates, terpenes and modified terpenes, aliphatic, cycloaliphatic and aromatic resins (C5 aliphatic resins, C9 aromatic resins, and C5/C9 aliphatic/aromatic resins), hydrogenated hydrocarbon resins, and their mixtures, terpene-phenol resins (TPR, used often with ethylene-vinyl acetate adhesives)), novolacs.
^Tse, Mun Fu (1989). "Studies of triblock copolymer-tackifying resin interactions by viscoelasticity and adhesive performance". Journal of Adhesion Science and Technology. 3 (1): 551–570. doi:10.1163/156856189x00407.