Braskem’s PIB – It’s low molecular weight in adhesives

PIB Polybutenes are liquid polymers, water white, with a wide viscosity range, chemically stable and resistant to oxidation by light and moderate temperatures

Braskem’s PIB has unique properties such as chemical resistance, low moisture and gas permeability, is odorless, colorless, oxidation resistant, non-toxic and non-irritating to the skin, and therefore can be used in a wide range of sealant and adhesive applications. It is a linear polymer with a narrow molecular weight distribution of about 2 (Mw/Mn). Its rheological properties are determined by Mw and temperature.

Braskem’s PIB is classified into three groups according to the molecular weight:

• High molecular weight PIB has a weight average, Mw, from 500,000 to 1,200,000 g/mol.
• Medium molecular weight PIB with a Mw from 40,000 to 150,000 g/mol offers flexibility, cohesive strength and elongation.
• Low molecular weight PIB with Mw < 15.000 g/mol is a liquid polymer with a range of viscosities. Low molecular weight PIB promotes tack and wetting and as a result adhesion.

Product Properties

With a Tg of -60 °C, Braskem’s PIB offers flexibility, permanent stickiness and moderate adhesion in adhesives over a wide temperature range due to its excellent cold flow. It acts as a polymer extender, rheology modifier, tackifier and wetting agent. Due to its low polarity, adhesion to some surfaces is moderate and therefore they are formulated into (hot melt pressure sensitive) adhesives in combination with tackifier resins such as rosin ester and/or hydrocarbon resins. Braskem’s PIB is well compatible with these resins, as well as with a variety of elastomers, polymers, rubbers, and aliphatic and aromatic solvents.

Applications

Braskem's PIB is used in automotive tapes for its good sealing and cushioning properties, is a proven component in pressure-sensitive hot melt adhesives such as butyl tape, used in building and construction applications. Since the PIB meets many FDA food contact requirements, it can also be used in tapes and labels for food packaging.

Want to know more about Braskem’s PIB?

You may be wondering how you can apply Braskem’s PIB to your products. We recommend you to check out this link or contact our specialist Jacques Everaert via the tab to your right!