Controlling the Tg of Viscoelastic Flexible Foams


 Number/Link: WO2013/131710

Applicant/Assignee: Evonik

Publication date: 12-09-2013 (German)

Gist”: Use of the di-salt of malic acid to fine-tune the Tg of visco flex foams.

Why it is interesting: The comfort properties of viscoelastic (“memory”) foams are to a large extend controlled by the glass transition temperature of the softblock, which in turn is controlled by NCO index, softblock molecular weight, crosslink density etc. Changing these parameters can be complex however because other properties -like airflow- are affected as well. This invention teaches the surprising effect of the di-sodium-salt of malic acid (hydroxybutanedioic acid) on the Tg of these foams. Apparently a small amount of the compound has a large effect on the Tg and can therefore be used to adjust the Tg without affecting other properties to a large extend.  E.g. about 0.1 php of the salt drops the Tg with 5.5°C, by comparison 0.1 php butanol lowers the Tg only by 0.3°C.

Malic Acid

Malic Acid

Leave a comment

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

  • Pages

  • Categories

  • Enter your email address to follow this blog and receive notifications of new posts by email.

    Join 1,089 other followers
  • Follow Innovation in PU on Twitter

%d bloggers like this: