Modification of Aminoplasts

For a purposeful variation of the properties of compositions based on carbamide and melamine resins with cellulose fillers use is made of various agents which modify the resins. Particularly good results are attainable by using benzoguana-mine as a modifier. The content of benzoguanamine may vary from 5 to 50% [5]. 

Aminoplasts based on urea-benzoguanamine-formaldehyde oligomers when compared to urea-formaldehyde press-materials are distinguished by an increased water- and heat-resistance, improved physico-mechanical properties, and insignificant shrinkage. 

In Ref. [6] results of modifying aminoresins with phenol and polyester resins to give them impact resistance, moisture resistance and dimensional stability for applications in electrical engineering. 

An investigation into the effect of certain organic silicon compounds on the properties of aminoplasts was made in Ref. [7]. It was shown that the modification of aminoplasts with siloxanes makes it possible to improve their stren h and performance indices, such as the collapse strain in bending, thermal resistance, and to reduce water absorption. The maximum effect is obtained by the use of 1-1.5% hydroxyloxane as a modifying additive. 

An overall trend towards an improvement of the properties of polymeric materials is also observed in the development of modified melamine-formaldehyde 

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