Polyamines starters

High Molecular Weight Polyether Polyols Based on Polyamine Starters. Autocatalytic Polyether Polyols [148-152]... 

To solve these problems, polyols with self-catalytic activity and of course with low volatility were created, using polyamines as starters [148-152]. These polyols, with an intrinsic catalytic activity, are chemically incorporated in the PU structure. As an immediate... 

A second important group of starters used in the synthesis of polyether polyols for rigid PU foams is the group of polyamines, aliphatic or aromatic, having 2-3 amino groups/mol (primary or secondary amino groups) such as ethylenediamine (EDA), diethylenetriamine (DETA), ortho-toluene diamine (o-TDA) and diphenylmethanediamine (MDA) [1,2] (see Chapter 4.2). The main properties of these polyamines which are of interest in polyurethane chemistry are presented in Table 13.2. 

Table 13.2 Some characteristics of polyamines used frequently as starters for polyether polyols for rigid PU foams ...

No. Polyamine used as starter Formula MW f Hydroxyl number, mg KOH/g... 

Aminic polyols are low molecular weight adducts of propylene oxide (PO) [and/or ethylene oxide (EO)] made from aliphatic or aromatic polyamines such as ethylenediamine (EDA), diethylene triamine (DETA) [1, 2], ortho-toluene diamine (o-TDA) [3, 4] or diphenylmethanediamine (MDA) [2, 5, 6]. Because these starters are liquid at room temperature (EDA, DETA) or low melting point solids (o-TDA, MDA), they are alkoxylated in the absence of solvents. 

The polyols for rigid foams (referred to as rigid polyols) discussed before (Chapters 13 and 14), are based on the alkoxylation of different polyols or polyamines, commercialised in a relatively high purity form. Some important starters for rigid polyols are obtained by the synthesis of the starter in situ, before the alkoxylation reaction, by the condensation reaction of some aromatic compounds (phenols, melamine and so on) with aldehydes (mainly formaldehyde), followed by the reaction of the resulting condensate with alkylene oxides. Some important rigid polyols based on the condensates mentioned are ... 

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