Polybutene-1 (PB-1) at first sight appears to be a conventional polyolefin. Based on its molecular structure, it resembles its well-known counterpart polypropylene (PP).
The extra methylene group incorporated into the side chains however has drastic implications with regard to PB-1’s affinity to polyethylene (PE).
This structural change represents a further mild reduction of polymer polarity and a lower entanglement density compared to the lower poly (a-olefins). These properties deliver a polymer with an intrinsic high shear sensitivity and low heat of fusion together with a melting point comparable to PE. These unique properties are what the packaging industry needs for producing easy-open packaging seals.
Blending minor amounts of PB-1 into PE is a prerequisite for developing an easy opening packaging technology. Typical applications where this technology is being applied by customers include sterilizable, deep freeze, vacuum, and modified atmosphere packaging.