HIPS is short for the high impact polystyrene, which is white opaque beads or granular particles. HIPS is essentially an impact-modified variety of PS, and its specific composition is PS and rubber. According to the size of HIPS modification range, it can be divided into three categories: medium impact PS, high impact PS and super high impact PS. In order to be suitable for different applications, various special grades of HIPS have been developed, such as flame retardant grade, stress crack resistance grade, high gloss grade, extremely high impact strength grade, glass fiber reinforced grade and low residual volatility grade, etc.
The outstanding characteristics of HIPS are easy processing, excellent dimensional stability, high impact strength and high rigidity. However, compared with PS, HIPS still has certain deficiencies in heat resistance, tensile strength, transparency, oxygen permeability, UV stability and oil resistance.
In addition to excellent impact properties, HIPS also has most of the advantages of PS, such as good rigidity, easy processing, high gloss (85% gloss) and easy coloring, etc., but its tensile strength and transparency decrease.
Specific performance of HIPS | |||
Performance | High impact PS | super high impact PS | |
butadiene oxygen /% | 5.1 | 14.5 | |
Relative density | 1.05 | 1.02 | |
Vicat softening point /℃ | 101 | 91 | |
Elastic Modulus /MPa | 2200 | 1600 | |
Izod impact strength (notched) /(kJ/m2 ) | 7.0 | 24.3 | |
Tensile Strength /MPa | 20.0 | 13.3 | |
elongation at break /% | 3.5 | 17 | |
