Polymer polyol is mainly used in polyurethane foam, which can increase the hardness of polyurethane soft foam and improve the overall performance of the foam. In order to increase the foam hardness, methods commonly used in the early days were: adding inorganic fillers to polyols, increasing the isocyanate index, or using TDI with a high 2,6-isomer content. Adding inorganic fillers to polyols increases the viscosity of the material, making the system unstable and difficult to process. While increasing the hardness of the foam and improving the density of the product, it also significantly reduces other physical properties. Although increasing the isocyanate index can increase the hardness, due to the increase in reaction heat, especially for low-density foams foamed with water, the possibility of core burning or even self-ignition of the foam increases.
Polymer polyol is a special bonded dispersion system containing solid organic fillers. During the foaming process, these dispersed organic solid particles have three functions: (1) Act as a gas nucleating agent to make the bubbles uniform and improve the foaming process; ( 2) Attached to the cell wall, it weakens the cell membrane, making the foam easy to open, increasing the porosity, and preventing the foam from shrinking; (3) The graft copolymer particles are attached to the polyurethane network, which greatly improves the strength of the foam. The network carrying capacity and strength have little impact on other physical and mechanical properties of the foam.
Polymer polyols are mainly used to produce high load-bearing (HL) and high recovery Resilient (HR) soft block foam and molded foam are used in carpet underlays, furniture cushions, vehicle seat cushions and automotive interior parts.
The 50% compression load of polyurethane foam produced using polymer polyols is the same The density is more than double that of ordinary polyurethane soft foam, which means that for foam materials with the same compression load, the density can be greatly reduced due to the use of polymer polyol, thereby reducing costs. This has practical value.
Ordinary polyurethane soft foam is used as cushioning material for vehicles and other vehicles as well as furniture seats ">, due to the poor load-bearing capacity, there is an uncomfortable feeling of "sitting down to the bottom". High-load-bearing polyurethane soft foam prepared with polymer polyol has high compressive load, tensile strength and damping properties, making it an ideal cushion material.
High resilience foam produced using ordinary high molecular weight and highly active polyether, formula The adjustable range is narrow and it is easy to produce closed cells, causing the foam to shrink. It must go through a rolling process to rupture the closed cells. The above shortcomings can be overcome by using polymer polyols and high-resilience foams with higher open cells can be obtained. Polymer polyols are used in combination with ordinary high-reactive polyethers and are currently the main polyol raw materials for high-resilience foams.
<font face=" Foam produced using polymer polyol as raw material has high modulus, strength and deformation recovery rate. As a shock-absorbing and energy-absorbing cushioning material, it is widely used in automobiles. Bumpers, energy-absorbing panels and packaging materials for precision instruments, etc. In addition, POP can also be used as a self-reinforcing polyol for microporous elastomers and adhesives.Various microporous or non-porous polyurethane fields such as � and sealants can improve the material's physical properties such as modulus and tensile strength.
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