ETD system

Electronic theses and dissertations repository

 

Tesi etd-04062011-112056


Thesis type
Tesi di dottorato di ricerca
Author
FARSETTI, SILVIA
URN
etd-04062011-112056
Title
Natural Resource Sustainability through Bio-based Polymers Development
Settore scientifico disciplinare
ING-IND/22
Corso di studi
INGEGNERIA CHIMICA E DEI MATERIALI
Commissione
tutor Prof. Lazzeri, Andrea
Parole chiave
  • Natural polyols
  • Thermal properties
  • Mechanical properties
  • Lignin
  • Flexible foams
  • Biobased polyurethanes
Data inizio appello
27/05/2011;
Consultabilità
completa
Riassunto analitico
In this work was presented a synthetic pathway to valorise lignin wastes to make a product that was more environmental friendly and economically viable than the polyurethanes produced by current synthetic processes.
The usage of lignin with suitable chain extenders, as a potential replacement to petroleum polyols, in the production of flexible foam polyurethanes, was investigated. Advantages of lignin is that it is a renewable resource, cheap and easily available and it is a waste material from the wood and pulp industries. Two different kind of lignin were employed, one from kraft and one from soda process, also the soda lignin was subjected to chemical modification process to improve its reactivity.The cell structure as well as physico-mechanical and thermal properties were characterized to compare with commercial analogues. It was investigated that liquefied lignin foams had high content of open cell, density, physico-mechanical and thermal properties were comparable with foams made with commercial petroleum based polyols. The properties of these foams was modulated introducing flexible chains in the macromolecular structure that can reduce the glass transition temperature of the materials and generate foams with higher flexibility.
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