Dissertations in Forestry and Natural Sciences

5 Aims and significance
Despite the fact that WPCs are recognized as potential
substitutes for the mineral oil based plastics and conventional
building products, they still lack certain desirable properties.
For example, one of the major limiting factors of the
applicability of WPCs is their excess water absorption, and this
can cause their swelling and increase their susceptibility to
microbial attack. In addition, as WPCs are increasingly being
used indoors, their impact on indoor air quality has not been
assessed. To overcome the limitations associated with WPCs, a
wide variety of additives has been developed (Sherman 2004).
Even though the additives, such as coupling agents, usually
provide at least a partial solution to the problems, additives are
usually relatively expensive and developed via synthetic routes.
Thus, the WPC industry needs novel, bio-based and
inexpensive solutions to replace these materials.
On the other hand, the efficient utilization of raw materials,
including industrial by-products, is becoming more relevant.
For example, considerable amounts of liquid waste are
generated in charcoal and ThermoWood ® production. The use
of these liquids in WPCs could provide benefits for both
industries, as material previously considered as waste would
become a valuable additive in WPCs. In order to explore this
possibility, the following aims were set for this thesis:
1. To explore if WPC granules could be effectively impregnated with
different types of wood distillates. The impregnation of WPC
granules with the distillates was tested in studies I, III and
IV using two types of commercial WPC granules and two
types of wood distillates.
2. To study whether PTR-TOF-MS is an applicable technique for
determining VOC emissions from WPCs. The suitability of
PTR-TOF-MS to determine VOC emissions from WPCs was
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