Sökning: "n-hexane diffusion"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden n-hexane diffusion.

1. 1. Small Molecule Diffusion in Spherulitic Polyethylene : Experimental Results and Simulations

   Författare :Alessandro Mattozzi; Ulf W. Gedde; Alan H. Windle; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; diffusion; polyethylene; poly ethylene-co-octene ; free volume; morphology; intermediate phase; spherulite; Monte Carlo simulation; Polymer chemistry; Polymerkemi;

   Sammanfattning : The diffusion of small-molecule penetrants in polyethylene is hindered by impenetrable crystals and by the segmental constraints imposed by the crystals on the penetrable phase. Liquid and vapour n-hexane sorption/desorption measurements were performed on metallocene catalyzed homogenous poly(ethylene-co-octene)s. LÄS MER

3. 2. Diffusion, Swelling and Mechanical Properties of Polymers

   Författare :Janis Ritums; KTH; []
   Nyckelord :diffusion; swelling; mechanical properties; polymers;

   Sammanfattning : Polymers capability to withstand harmful interactions withdifferent environments can be determined by looking at thetransport and mechanical properties of the material exposed tothe medium. The diffusion of a penetrant in a polymer and itsswelling characteristics can be verified by a simplesorption-desorption experiment followed by methodical analysisof the data. LÄS MER

4. 3. The influence of Morphology on the Transport and Mechanical Properties of Polyethylene

   Författare :Bereket Neway; KTH; []
   Nyckelord :n-hexane diffusion; polyethylene; free volume; solubility; sorption; desorption; mechanical properties; orientation; thermal properties; blend;

   Sammanfattning : The sorption/desorption behaviour of n-hexane in high molarmass linear polyethylene (PE) and branched PEs with 0.39 and5.09 hexyl branches per 100 main chain C atoms andcrystallinities between 4 and 82% at 298 K has been studied.Crystal core contents determined by Raman spectroscopy werealways lower than those determined by density measurements. LÄS MER

5. 4. Simulations of Semi-Crystalline Polymers and Polymer Composites in order to predict Electrical, Thermal, Mechanical and Diffusion Properties

   Författare :Fritjof Nilsson; Mikael Hedenqvist; Gerhard Goldbeck; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Several novel computer simulation models were developed for predicting electrical, mechanical, thermal and diffusion properties of materials with complex microstructures, such as composites, semi-crystalline polymers and foams. A Monte Carlo model for simulating solvent diffusion through spherulitic semicrystalline polyethylene was developed. LÄS MER

7. 5. A new technique to assess dermal absorption of chemical vapor in vitro by thermogravimetric analysis (TGA)

   Författare :Matias Rauma; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :;

   Sammanfattning : There is a huge lack of dermal uptake data for chemicals, and it is frequent with large variations in reported permeability coefficients for chemicals with more than one data set, showing the need for a new and standardized in vitro method. The overall aim of this thesis was to develop the new method of measuring dermal absorption of chemical vapor using the TGA method. LÄS MER