Ask Dr. Dave / End User Features / Info for Assembly / Columns / Finished Adhesives and Sealants

Ask Dr. Dave: December 2013

Are all cyanoacrylate adhesives brittle when cured?

Question: I am trying to bond several rubber parts together. I would like to try a cyanoacrylate adhesive, but I hear they are very brittle when cured. Is that true?

Answer: Unfortunately, because some of the common cyanoacrylates tend to be somewhat brittle in comparison to other adhesives when used to bond rigid substrates, they are rarely considered for bonding rubbers. However, these adhesives have been widely used over the years for rubber bonding. For example, so-called “O-ring kits” are sold to make custom-sized O-rings from rubber cord stock, and some critical applications (like bonding rubber balloons on heart catheters) have always used cyanoacrylates. The rubber actually absorbs the stresses put on the bond, and the brittleness of the adhesive is not an important issue.

Cyanoacrylates give very good bond strengths on common rubbers like nitrile, neoprene and Buna N, with strengths often exceeding the strengths of the rubber. In fact, more rigid substrates can now be bonded with more flexible cyanoacrylates because of advancements in the technology over the years. Rubber-toughened cyanoacrylates are true impact-resistant structural adhesives. The first toughened cyanoacrylates were always black in color because they were toughened with rubbers containing carbon black filler, but white and colorless versions are now available.

 Any views or opinions expressed in this column are those of the author and do not represent those of ASI, its staff, Editorial Advisory Board or BNP Media. 

Did you enjoy this article? Click here to subscribe to Adhesives & Sealants Industry Magazine.

Recent Articles by Dave Dunn

You must login or register in order to post a comment.



Image Galleries

ASI April 2014 Photo Gallery

Our April 2014 issue is now available!


ExxonMobil Tackifier Expansion

Dwight Tozer, vice president of ExxonMobil’s Adhesion Industry business, discusses the company’s latest tackifier expansion project with Editor-in-Chief Susan Sutton.

More Podcasts

Adhesives & Sealants Industry Magazine

ASI April 2015 cover

2015 April

Our April issue includes previews of the ASC Spring Convention and Expo and the European Coatings Congress and Show, as well as articles detailing end-use applications in transportation, raw materials and equipment. Check it out today!

Table Of Contents Subscribe

Better Jobs

Is the economy prompting you to consider leaving your job for a better one?
View Results Poll Archive


Handbook of Sealant Technology

The Handbook of Sealant Technology provides an in-depth examination of sealants, reviewing their historical developments and fundamentals, adhesion theories and properties, and today’s wide range of applications.

More Products

ASI 2014 Buyers GuideASI's Buyers' Guide

Annual purchasing resource for equipment used in the manufacture/formulation of adhesives, sealants, pressure sensitives, tapes and labels and for application of finished adhesives. 


facebook_40px twitter_40  youtube_40pxlinkedin_40 google+ icon ASI 30px

Clear Seas Research

With access to over one million professionals and more than 60 industry-specific publications, Clear Seas Research offers relevant insights from those who know your industry best. Let us customize a market research solution that exceeds your marketing goals.