| 摘要 |
<p>The present invention relates to the preparation of foamable polymer materials which may be converted into polacrylimide and polymethacrylimido foam materials upon heating; The foamable polymer materials are prepared by a process which comprises radically polymerising a monomer composition comprising: A) acrylonitrile and/or methacrylonitrile and acrylic acid and/or methacrylic acid, the said nitrile(s) and acid(s) being employed in a molar ratio in the range 2:3 to 3:2; and, if desired, B) up to 20% (based on the weight of A) of at least one further radically polymerisable comonomer; the said monomer composition further containing as a propellant, 1 to 15% (based on the weight of A) and (when present B) of at least one monohydric aliphatic alcohol contining 3 to 8 carbon atoms. The foam materials produced by the method according to the present invention are particularly suitable for preparing laminated structures.</p> |
