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Isocyanate-free polyurethane from cyclic carbonates : Synthesis, application and evaluation

Wallerek, Christoffer LU (2016) KTE720 20132
Centre for Analysis and Synthesis
Abstract
Polyurethane is a widely used polymer with a lot of different applications due to its versatility and
often resilient properties. The polymeris often prepared as a two component system consisting of
polyols and isocyanates and can be cured at relatively low temperatures. Even though the formed
polymer is hazardless the isocyanate used in the manufacture is dangerous in itself, but even more so
is the often used precursor phosgene. Large quantities of phosgene and isocyanates are handled in
the production of isocyanates and pose a threat to the environment and the people working with the
production, and to great extent the application works. There is however a relatively new and
“greener” alternative to commercially available... (More)
Polyurethane is a widely used polymer with a lot of different applications due to its versatility and
often resilient properties. The polymeris often prepared as a two component system consisting of
polyols and isocyanates and can be cured at relatively low temperatures. Even though the formed
polymer is hazardless the isocyanate used in the manufacture is dangerous in itself, but even more so
is the often used precursor phosgene. Large quantities of phosgene and isocyanates are handled in
the production of isocyanates and pose a threat to the environment and the people working with the
production, and to great extent the application works. There is however a relatively new and
“greener” alternative to commercially available polyurethane which is based on cyclic carbonates
and amines. This NIPU (Non-Isocyanate PolyUrethane) production and comparison to commercial PU
are the main focus of this master thesis. From the available literature NIPU is commonly prepared
from 5-membered cyclic carbonates.But via internal competence and research from Perstorp AB and
from LundUniversity a possible way to prepare a more reactive 6-membered monomer cyclic
carbonate to be cross-linked with amines were formed.
As a primary objective a polymer with an acrylate skeleton and cyclic functionality would be crosslinked
with isophorone-diamine and compared with a similar acrylate-polyol polymer cross-linked
with isophoronediisocyanate (IPDI). If the primary objective would prove too difficult, a crosslinking
between a di-cyclic carbonate (di-TMPC) and polyether amines (Jeffamines) should be evaluated as
films. The synthesis and final products were to be analyzed with gas chromatography, FT-IR, GPC and
standardized film evaluation methods.The monomer was to be prepared via acrylate-esterification of
tri-methylol-propane (TMP), followed by carbonation with di-methyl-carbonate (DMC). The cyclic
carbonate with acrylate functionality would then be polymerized before being cross-linked with
amines to create a multifunctional polyurethane polymer.
The esterification process started with TMP being ring-protected with acetone before being
transesterified. Later, the acetone group was removed to allow for carbonation. The three first
synthesis steps were relatively simple in their set-up and a product purity of 93.67 % were obtained.
The carbonation proved more complicated and several approaches were tried. The most effective
way for preparing the precursor for the cyclic product was an enzymatic approach with N435, an
enzyme kindly provided from Novozyme. At a reaction time of 45 h at 60 ℃ an estimated mass
content of 53% of single coupled monomer were achieved. The other methods included a higher
temperature thermal reaction, hydroxide catalyzed, DBTDL catalyzed and enzymatic processes at
lower temperatures. All other methods besides the enzymatic approach yielded no product or
precursor mass content of over 10%. The primary objective were put on hold in favor of the
secondary aim.
The secondary approach encountered problems with solubility of the di-TMPC and the Jeffamines
which resulted in the lack of the polymer reactions necessary for film evaluation. The two solvents
(cyclohexanone and methylethylketone) used to try and overcome this problem did not solve the diTMPC
effectively enough despite raised temperature and sufficient time. Several DSC-scans did
however confirm some exothermic reactions occurring at room temperature and an almost
instantaneous reactivity at the melting point of di-TMPC. FT-IR was used to confirm the presence of
urethane bonding and the cyclic carbonate decomposition in a series of scans.
There are still different monomers to be evaluated to compare system and physical data for the pure
cyclic carbonate in the future. (Less)
Popular Abstract (Swedish)
Det pågår ständigt en utveckling för att minska både risker för miljö och hälsa inom den kemiska industrin. Oftast handlar det om att förbättra existerande processer eller att helt enkelt hitta nya vägar till samma produkt och i grunden ligger forskning bakom framgångarna.
Please use this url to cite or link to this publication:
author
Wallerek, Christoffer LU
supervisor
organization
course
KTE720 20132
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Isocyanate, polyurethane, cyclic, carbonate, NIPU, polymer, PU, polymer technology
language
English
id
8870685
date added to LUP
2024-02-28 14:29:04
date last changed
2024-02-28 14:29:04
@misc{8870685,
  abstract     = {{Polyurethane is a widely used polymer with a lot of different applications due to its versatility and
often resilient properties. The polymeris often prepared as a two component system consisting of
polyols and isocyanates and can be cured at relatively low temperatures. Even though the formed
polymer is hazardless the isocyanate used in the manufacture is dangerous in itself, but even more so
is the often used precursor phosgene. Large quantities of phosgene and isocyanates are handled in
the production of isocyanates and pose a threat to the environment and the people working with the
production, and to great extent the application works. There is however a relatively new and
“greener” alternative to commercially available polyurethane which is based on cyclic carbonates
and amines. This NIPU (Non-Isocyanate PolyUrethane) production and comparison to commercial PU
are the main focus of this master thesis. From the available literature NIPU is commonly prepared
from 5-membered cyclic carbonates.But via internal competence and research from Perstorp AB and
from LundUniversity a possible way to prepare a more reactive 6-membered monomer cyclic
carbonate to be cross-linked with amines were formed.
As a primary objective a polymer with an acrylate skeleton and cyclic functionality would be crosslinked
with isophorone-diamine and compared with a similar acrylate-polyol polymer cross-linked
with isophoronediisocyanate (IPDI). If the primary objective would prove too difficult, a crosslinking
between a di-cyclic carbonate (di-TMPC) and polyether amines (Jeffamines) should be evaluated as
films. The synthesis and final products were to be analyzed with gas chromatography, FT-IR, GPC and
standardized film evaluation methods.The monomer was to be prepared via acrylate-esterification of
tri-methylol-propane (TMP), followed by carbonation with di-methyl-carbonate (DMC). The cyclic
carbonate with acrylate functionality would then be polymerized before being cross-linked with
amines to create a multifunctional polyurethane polymer.
The esterification process started with TMP being ring-protected with acetone before being
transesterified. Later, the acetone group was removed to allow for carbonation. The three first
synthesis steps were relatively simple in their set-up and a product purity of 93.67 % were obtained.
The carbonation proved more complicated and several approaches were tried. The most effective
way for preparing the precursor for the cyclic product was an enzymatic approach with N435, an
enzyme kindly provided from Novozyme. At a reaction time of 45 h at 60 ℃ an estimated mass
content of 53% of single coupled monomer were achieved. The other methods included a higher
temperature thermal reaction, hydroxide catalyzed, DBTDL catalyzed and enzymatic processes at
lower temperatures. All other methods besides the enzymatic approach yielded no product or
precursor mass content of over 10%. The primary objective were put on hold in favor of the
secondary aim.
The secondary approach encountered problems with solubility of the di-TMPC and the Jeffamines
which resulted in the lack of the polymer reactions necessary for film evaluation. The two solvents
(cyclohexanone and methylethylketone) used to try and overcome this problem did not solve the diTMPC
effectively enough despite raised temperature and sufficient time. Several DSC-scans did
however confirm some exothermic reactions occurring at room temperature and an almost
instantaneous reactivity at the melting point of di-TMPC. FT-IR was used to confirm the presence of
urethane bonding and the cyclic carbonate decomposition in a series of scans.
There are still different monomers to be evaluated to compare system and physical data for the pure
cyclic carbonate in the future.}},
  author       = {{Wallerek, Christoffer}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Isocyanate-free polyurethane from cyclic carbonates : Synthesis, application and evaluation}},
  year         = {{2016}},
}