Views: 275 Author: Vickey Publish Time: 2023-06-20 Origin: Site
With its reactive primary hydroxyl functionality and linear structure, 1,4-butanediol (BDO) is a flexible liquid diol intermediate that makes it easy to create polyurethane elastomers with the best possible balance of characteristics and price.
Most processors use 1,4-BDO as their preferred chain extender for MDI or H12MDI systems. When acting in this capacity, BDO effectively produces crystalline "hard segment" domains that effectively microphase separate when it combines with MDI, H12MDI, and other aliphatic isocyanates or prepolymers. Numerous investigations have demonstrated that the degree and accuracy of this hard-block phase separation strongly influence the characteristics of polyurethane. BDO, a urethane chain extender, produces polyurethane elastomers that are hard, strong, long-lasting, and thermally stable.
Uncrosslinked BDO-MDI domains in thermoplastic polyurethane (TPU) compositions can melt and flow at high temperatures to enable thermoplastic processing. When cooled, the linked networks reform to create sturdy elastomeric compositions.
Linearity is the first need for a useful diol-urethane intermediate. The second requirement is that the number of CH2 groups in the repeating chain should preferably be even. The overall performance characteristics of the produced elastomers benefit from the molecular-level chain packing of the various hard and soft segments of polyurethanes.
Our BDO's low moisture content allows for superior stoichiometry control by preventing the interaction of water with isocyanates and the subsequent emission of CO2 gas bubbles.235°C (455°F) is the high boiling point of BDO, while 19–20°C (68°F) is the low boiling point. BDO must be transferred at the proper storage and handling temperatures since it solidifies at around 20°C. BDO has an equivalent mass of 45.06 and a hydroxyl content of 1245 mg KOH/g.
BDO has a low level of toxicity and is non-hazardous. It can be handled with ease using conventional polyurethane techniques. BDO has a two-year shelf life, provided it is stored and handled correctly.BDO is a regulated product. It is only intended for use in industrial applications and is not intended for human consumption.
1,4-Butanediol is used extensively as a chain extender in the manufacture of polyurethanes. In MDI systems, BDO provides:
High, consistent reactivity and shorter demold times with MDI, H12MDI and prepolymers.
Hard-block domains that efficiently microphase separate affording tough networks.
Polyurethanes with a good balance of hardness and low temperature flexibility.
Polyurethanes exhibiting high strength, durability, and thermal stability.
TPUs with good melt stability and excellent processing characteristics.
Good compatibility with other system components.