Study of Reactive Melt Processing Behavior of Externally Plasticized Cellulose Acetate in Presence of Isocyanate

Materials

Rafael Erdmann¹  Stephan Kabasci¹  Joanna Kurek¹  Stefan Zepnik¹ 

[1] Fraunhofer Institute for Environmental, Safety, and Energy Technology (UMSICHT), Osterfelder Straße 3, 46047 Oberhausen, Germany; E-Mails:

关键词: reactive melt processing;    crosslinking;    cellulose acetate;    plasticizer;    rheology;    thermal properties;   

DOI  :  10.3390/ma7127752

来源: mdpi

【 摘 要 】

Two types of externally plasticized cellulose acetate (CA) were chemically modified using 4,4'-methylene diphenyl diisocyanate (MDI) as crosslinking agent. Crosslinking was performed in the molten state by means of melt mixing in an internal mixer. The viscoelastic properties of the non-crosslinked, externally plasticized CA show typical temperature dependence, similar to conventional thermoplastics. A strong increase in storage modulus is observed with increasing crosslink density indicating that the crosslinked compounds exhibit predominately elastic response. The complex viscosity also increases considerably with increasing crosslink density and does not reach the typical Newtonian plateau at low radial frequencies any more. The viscoelastic properties correlate well with the data recorded online during reactive melt processing in the internal mixer. In comparison to the non-crosslinked CA, the crosslinked compounds show higher glass transition temperature, higher VICAT softening temperatures, improved thermal stability and lower plasticizer evaporation at evaluated temperatures.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.