Long Chain Branching, Part 2 – Experimental results

Hypothesis:  long chain branching of LLDPEs can improve melt strength in terms of drawability.

 We irradiated 3 LLDPE feedstocks with an electron beam and compared the properties of the 3 processed resins to a LDPE Control.  The starting samples were:

Radiation Processing

We dosed the samples with a 150kW, 4.5 MeV electron beam accelerator.  The electron beam irradiation initially breaks the polymer chains, creating free radicals that subsequently reform as long chain branches.  Improvements in melt behavior are attributed to this branched structure.

Observations

We observed a decrease in melt index and an increase in melt tension as dose was increased.  For LLDPE sample B, at dose level 3 the melt index and melt tension are equivalent to the LDPE Control.  This indicates that the desirable melt strength properties of LDPE can be imparted into LLDPE.

In Part 3 of this study we will blend these dosed samples with polyethylene to increase the properties of the alloy.

Share this onTweet about this on TwitterShare on FacebookShare on Google+Share on LinkedInEmail this to someone
This entry was posted in Crosslinking & Polymer Modification, E-Beam, Rheology Control. Bookmark the permalink. Both comments and trackbacks are currently closed.

About E-Beam Services

E-BEAM Services, Inc. is a leading supplier of contract electron beam processing services, with more than 450kW of installed accelerator capacity — enough to process nearly one billion pounds of material annually. Electron beam processing effectively and efficiently creates useful changes in material properties and performance, such as polymer crosslinking and chain scissioning. E-beam processing is also widely used for the sterilization of medical devices and pharmaceuticals as well as bioreduction.