Quinoline insolubles (qi) in medium-temperature bitumen refer to bitumen components that are insoluble in quinoline solvents, which are usually composed of aromatic compounds with high molecular weight and have certain viscosity and thermal stability. In ointment, a viscous liquid composed of bitumen and mineral oil, quinoline insolubles can do the following:
1. Increase viscosity: Due to its high molecular weight and large molecular structure, quinoline insoluble matter can increase the viscosity of the ointment, so that it has better adhesion and spreadability when applied.
Improved rheological properties: Quinoline insoluble substances can form a network structure in the paste, which helps to improve the rheological properties of the paste, so that it still maintains good viscosity stability at high temperatures.
Improved thermal stability: Quinoline insolubles typically have high thermal stability and are able to maintain their physical properties in high-temperature environments, which helps to improve the high temperature resistance of pastes.
4. Enhance corrosion resistance: The aromatic compounds in quinoline insoluble matter have certain corrosion resistance, which can enhance the protective effect of the ointment on metals and other materials and prevent corrosion.
Affects the softening point of asphalt: The presence of quinoline insolubles can affect the softening point of asphalt, giving the paste better viscoelasticity over a specific temperature range.
6. Provide suspension medium: the high molecular weight compounds in quinoline insoluble matter can be used as suspension medium to help the solid particles in the paste to remain dispersed and prevent sedimentation.
Affect the storage stability of the ointment: Quinoline insoluble matter can reduce the stratification of the ointment during storage and improve its storage stability.
However, the content of quinoline insolubles needs to be moderately controlled, and too high a content may cause the viscosity of the paste to be too large, affecting its application performance. Therefore, in practical applications, according to the specific requirements and uses of the ointment, appropriate medium-temperature asphalt will be selected, and the content of quinoline insolubles will be adjusted to achieve the best performance.