Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Glass Transition Temperature

Glass Transition Temperature

Glass Transition Temperature

Can the glass transition (Tg) of a an adhesive be increased by increasing the cure temperature?

RE: Glass Transition Temperature

Ayup.  Again, in general.  And the thing is, it's all temperature AND time related.  I.e., a slightly lower temperature for a longer duration could give higher properties than a higher temperature, shorter duration cure.

RE: Glass Transition Temperature

Thanks btrueblood, you were most helpful in all your answers.

RE: Glass Transition Temperature

Increasing cure time and temperature will increase Tg by increasing degree of cure. But,you cannot go above 100% degree of cure. For most epoxies and bmi's that I'm familiar with you will get about 90% cure after 4 hours at a given temperature. But even after days at one temperature you might be able to get more cure if you raise the temperature. However, there is a maximum Tg for any thermoset and raising temperature or time will not increase Tg above that.

Degree of cure is usually determined by DSC where the energy released during a ramp to cure (2C/min) is measured. Then if you measure a cured sample with the same test it will measure "residual delta H". If that is 10% of what was measured in the first test then you have a 90% degree of cure.


Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


White Paper - PLM and ERP: Their Respective Roles in Modern Manufacturing
Leading manufacturers are aligning their people, processes, and tools from initial product ideation through to field service. They do so by providing access to product and enterprise data in the context of each person’s domain expertise. However, it can be complicated and costly to unite engineering with the factory and supply chain. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close