effects of maleic anhydride on the curing of furfuryl...

Nadine Herold · Eberswalde University for Sustainable Development – University of Applied Sciences · Faculty of Wood Science and Technology

Oktober 31, 2012

Nadine Herold Faculty of Wood Science and Technology

[email protected]

Nadine Herold, Tobias Dietrich, Warren J Grigsby, Robert A Franich, Anja Winkler, Beate Buchelt, Alexander Pfriem

Effects of Maleic Anhydride on the Curing of Furfuryl Alcohol in Wood

Veneer Studied by DSC


background

project: enhanced veneer moulding and form-fixation by furfuryl alcohol impregnation and polymerization at elevated temperatures

objective curing profiles of furfuryl alcohol in wood veneer were studied using Differential Scanning Calorimetry (DSC)


samples

•  maple veneer specimens •  impregnated with differently composed solutions:


DSC measurements •  the DSC measurements were performed on a

TA instruments Q1000 DSC under nitrogen atmosphere •  standard aluminium pans

•  sample weight: 5 - 6.5 mg

•  method 1: temperature ramp with a heating rate of 10 ºC/min from 20 to 200 ºC

•  method 2: isothermal temperature profiles at 80, 100, 120, and 140 ºC with an initial ramp of 100 ºC/min


results: heating ramp

122 °C



122 °C 147 °C



122 °C 147 °C

154°C



122 °C



~122 °C 135 °C



~122 °C 135 °C 155 °C



~122 °C 147 °C



~122 °C 147 °C

162 °C



~122 °C 147 °C

162 °C

168 °C



157 °C



~157 °C


results: isothermal temperature profiles


summary: DSC temperature ramp

•  maleic anhydride influences significantly the furfuryl alcohol polymerization

•  low maleic anhydride content requires a higher temperature to affect the same degree of polymerization

•  dilution of the furfuryl alcohol/maleic anhydride treatment mixture with ethanol retarded the polymerization reactions


summary: DSC isothermal temperature profiles

•  high reaction temperatures lead to a more rapid, exothermic cure •  temperatures less than 100 °C result in low rates of polymerization and

potential for higher furfuryl alcohol loss through evaporation

•  ethanol dilution shows a less intense and retarded polymerization


in addition: sample weight change during the modification

•  sample weights were measured - absolutely dry

- after impregnation and low-pressure application - after curing at 140 °C for 3 h


polymer weight


results: polymer formation •  polymer formation (by weight) is linear related to the maleic anhydride

content inside the samples •  ethanol-diluted impregnation solutions reduce the degree of

polymerization

•  the curing temperature also determines the polymer formation

à what are the effects of these parameter on the polymers’ constitution?


Thank you for your attention!

Acknowledgement: The authors are grateful for the financial support of the German Research Foundation (DFG, PF 686/4-1), AiF (16735 BR), and COST (STSM-RA - New Zealand-06283). We also greatly appreciate the supply of the furfuryl alcohol by International Furan Chemicals B.V.

effects of maleic anhydride on the curing of furfuryl...

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