Storage stability of injection-molded starch-zein plastics under dry and humid conditions

Research output: Contribution to journalArticle

24 Citations (Scopus)

Abstract

Corn starch and zein mixtures (4:1 dry weight) were extruded and injection-molded in the presence of plasticizers (glycerol and water). Tensile strength and percentage elongation of the molded plastics were measured before and after 1 week of storage under a dry or humid condition (11 or 93% RH). With 10-12% glycerol and 6-8% water, injection-molded plastics had relatively good tensile properties (20- to 25-MPa tensile strength and 3.5-4.7% elongation). But while exposed to dry conditions (11% RH), the molded plastics lost weight (0.5-1.5% in 7 days) and became very brittle, with significant decreases in tensile strength and elongation. Partial replacement (5-10%) of starch with a maltodextrin (average DE 5) reduced the glass transition and melting temperatures of the starch-zein mixture as well as the dry storage stability. Using potato starch instead of corn starch significantly improved the dry storage stability of the injection-molded starch-zein plastics (18- vs 11-MPa tensile strength). Anionic corn starches with a maleate or succinate group (DS<0.01) produced injection-molded plastics with improved tensile properties and storage stability. Plastics prepared from the starch maleate and zein mixture retained the strength during 1 week of dry storage without a significant change (26-MPa tensile strength and 3.7% elongation after 1 week of storage).

Original languageEnglish
Pages (from-to)111-120
Number of pages10
JournalJournal of Environmental Polymer Degradation
Volume2
Issue number2
Publication statusPublished - 1994 Apr 1
Externally publishedYes

Fingerprint

Zein
Starch
starch
plastic
Plastics
tensile strength
Tensile strength
Elongation
maize
Glycerol
Tensile properties
Plasticizers
Water injection
Succinic Acid
potato
Melting point
replacement
melting
glass
water

ASJC Scopus subject areas

  • Environmental Science(all)
  • Polymers and Plastics

Cite this

Storage stability of injection-molded starch-zein plastics under dry and humid conditions. / Lim, Seung Taik; Jane, J.

In: Journal of Environmental Polymer Degradation, Vol. 2, No. 2, 01.04.1994, p. 111-120.

Research output: Contribution to journalArticle

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