Tackiness
In general, the tackiness of Indopl® polybutenes increases as molecular weight increases. The tackiness of formulations containing polybutene depends upon the polybutene grade and concentration and also upon the compatibility of polybutene with the other components of the mixture. Specific data about the tackiness of adhesives, rubbers and polyethylene films formulated with polybutene are available upon request by e-mailing our technical experts.
Thermal Properties
- Due to the viscous nature of the higher molecular weight polybutenes, it is typical to heat them during storage and transfer for ease of handling. Hence the thermal properties such as heat capacity and thermal conductivity are important in determining the most effective form of heating.
- The specific heat capacity of polybutene increases with temperature and decreases with molecular weight and viscosity. The thermal conductivity of polybutene tends to increase as the molecular weight and viscosity increases.
Thermal Decomposition, Volatility and Evaporation
- Indopol polybutenes are stable at room temperature but decompose at high temperature. The rate of decomposition becomes significant at about 200°C and is rapid above 250°C. Thermal decomposition yields lower molecular weight polybutene fragments, but at sufficiently high temperature the major product is isobutene.
- Low molecular weight, low flash point materials such as butenes are generated when polybutenes are stored hot for an extended period. Under these circumstances, storage under an inert gas atmosphere is recommended in order to prevent the formation of explosive mixtures. For more details on handling and storage of Indopol polybutenes contact our technical experts. E-mail our technical experts for advice.
- The depolymerization of polybutenes is a very valuable property, since it confers on the higher molecular weight grades the ability to volatilize before rapid combustion takes place. This volatilization occurs cleanly and without the formation of carbonaceous and tarry matter found when other materials (e.g. mineral oils) are heated strongly. This property is a particular advantage in non-staining metal working applications and in two-stroke lubricants. The low level of deposits formed during the decomposition of polybutene has been demonstrated by the Conradson carbon residue test.