1.Hydroxyl value
The amount of hydroxyl (-OH) contained in 1 gram of polymer polyol is equivalent to the number of milligrams of KOH, in mgKOH/G.
2.equivalent
The average molecular weight of a functional group.
3.Isocyanate content
The content of isocyanate in the molecule
4.Isocyanate index
Indicates the degree of excess isocyanate in polyurethane formulas, usually denoted by the letter R.
5.Chain extender
It refers to low molecular weight alcohol and amine compounds that can extend, expand, or form spatial reticular crosslinking of molecular chains.
6.Hard section
The chain segments formed by the reaction of isocyanates, chain extenders, and crosslinking agents on the main chain of polyurethane molecules have large internal cohesion, large spatial volume, and large rigidity.
7.Soft section
The carbon-carbon backbone polymer polyol has good softness and is a flexible segment in the polyurethane backbone.
8.One-step method
Refers to the method of mixing oligomer polyols, diisocyanates, chain extenders and catalysts at the same time and injecting them directly into the mold to cure and form at a certain temperature.
9.Prepolerization method
First, the oligomer polyol and diisocyanate are prepolerized to generate a polyurethane prepoler with a terminal NCO group. When pouring, the prepoler is reacted with a chain extender to prepare a polyurethane elastomer. The method is called the prepolerization method.
10.Semi-prepolerization method
The difference between the semi-prepolerization method and the prepolerization method is that part of the polyester polyol or polyether polyol is added to the prepoler in the form of a mixture with a chain extender, catalyst, etc.
11.Reactive injection molding
Also known as Reaction Injection molding RIM (Reaction Injection Moulding), it is a process in which oligomers of small molecular weight are measured in liquid form, mixed instantly and injected into the mold at the same time, and react quickly in the mold cavity, the molecular weight of the material increases rapidly, and a brand new polymer containing a new characteristic group structure is generated at an extremely fast speed. Polymer process.
12.Foaming index
That is, the number of parts of water equivalent to 100 parts of polyether is defined as the foaming index (IF).
13.Foaming reaction
Generally refers to the reaction where water reacts with isocyanate to form substituted urea and releases CO2.
14.Gel reaction
Generally refers to the formation reaction of carbamate.
15.Gel time
Under certain conditions, the time it takes for the liquid substance to form a gel.