Abstract
A mechanical process called solid-state shear pulverization (SSSP) was used to create blends or composites of polyethylene (PE) and starch that resulted in damaged granular structures. Because starch granules are unchanged when polymer/starch blends are made by melt mixing, this is the first time that damage (surface roughening, cracking, and clustering) to starch granule morphology has been reported in polymer/starch blends or composites. These morphological changes result in a 29% reduction in oxygen permeability for a 70/30 wt% PE/starch blend made by SSSP relative to neat PE; this compares with a 21% reduction in oxygen permeability when a similar blend is made by melt processing. In addition, relative to neat PE, the tensile modulus of a 70/30 wt% PE/starch blend is increased by 20% in the damaged starch case (vs. 10% in the blend made by melt mixing) while the reduction in tensile strength is significantly smaller than that found in melt-mixed blends.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1066-1074 |
| Number of pages | 9 |
| Journal | Polymer |
| Volume | 48 |
| Issue number | 4 |
| DOIs | |
| State | Published - Feb 9 2007 |
Funding
We acknowledge the support of Northwestern University, funding from the NSF-MRSEC program (Grants DMR-0076097 and DMR-0520513), and the use of equipment in shared user facilities managed by the Materials Research Center at Northwestern University. We thank Prof. L.C. Brinson for the use of her Minimat Tester and additionally thank Dr. Katsuyuki Wakabayashi for his assistance.
Keywords
- Polyethylene
- Solid-state shear pulverization
- Starch
ASJC Scopus subject areas
- Organic Chemistry
- Polymers and Plastics
- Materials Chemistry