As people's living standards improve, large-capacity refrigerators and freezers are increasingly becoming the mainstream choice. The expansion of the volume of the refrigerator liner puts forward higher requirements for the strength of the liner material. At present, the large particle size materials for refrigerator liners are mainly ABS (Acrylonitrile Butadiene Styrene) and HIPS (High Impact Polystyrene). Among them, HIPS has a cost advantage over ABS and has a promising market prospect.

Low cis polybutadiene rubber (LCBR) can be used as an additive component in the modification of HIPS for refrigerator liners to improve product toughness and solvent resistance, so that it is not easy to crack at low temperatures, to meet the needs of the refrigerator liner materials for the use of the working environment. Domestic due to the lack of large particle size HIPS modified with polybutadiene rubber industrial production technology, the product has been monopolized by foreign countries, the production cost of HIPS products for refrigerator liners remains high.

HIPS is polystyrene (PS) in the rubber molecular chain grafting modified resin materials, with high impact strength, good mechanical properties, good dimensional stability, easy processing (low scrap rate), easy to mold (molding shrinkage rate is small), etc., can replace the ABS resin, widely used in home appliances, automobiles and toys and other fields.

How does polystyrene resin "change" into HIPS resin?

Ordinary polystyrene resin is a non-toxic, odorless, colorless, transparent solid, not easy to deform, good chemical corrosion resistance, etc., but also has a very high degree of transparency, light transmittance of more than 90%, and low prices, can be widely used in packaging materials, construction materials, electrical appliances, furniture and toys and other fields. However, it is a brittle material similar to glass, easy to break when impacted by external forces, and easy to crack at low temperatures.

Low cis polybutadiene rubber (LCBR) refers to polybutadiene rubber with a cis-1,4-structure content of 30% to 40%, which can be categorized into resin-grade and rubber-grade according to applications. Among them, resin grade LCBR is mainly used for the modification of high-grade resins, which has the advantages of good color, good elasticity, strong abrasion resistance, etc., and can also maintain good mechanical properties at low temperatures. LCBR "mixed" into the polystyrene resin made of HIPS resin, not only to retain the original characteristics of polystyrene resin, but also to make up for the polystyrene resin is fragile, easy to crack at low temperatures and other deficiencies, significantly improve the toughness of the product and low temperature cracking resistance.

Low cis polybutadiene rubber (LCBR)

How to make a qualitative leap in polystyrene resin?

In HIPS resin, polystyrene is the continuous phase, the rubber phase is the dispersed phase, and the dispersed phase contains a large number of polystyrene, which divides the rubber phase into a number of small cells, commonly known as the "island structure", as if the low cis-polybutadiene rubber as the "skeleton As if the low-cis polybutadiene rubber as the "skeleton" to build a three-dimensional mesh structure, countless polystyrene particles filled in the low-cis polybutadiene rubber built around the grid, so that the modified material has both the advantages of the two materials. When the HIPS material is subjected to external impact, the rubber phase can absorb a large amount of energy, thus improving the impact resistance of the HIPS material. The mesh structure of low cis-polybutadiene rubber can well "wrap" the polystyrene particles, thus improving the low-temperature cracking performance of polystyrene resin and greatly improving the toughness of the modified HIPS material.