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Synthesis and chemical recycling investigations of polythioureas

de Menezes, Rafael N.L. LU orcid ; Gordivska, Olga LU ; Nguyen, Tran Tam LU ; Warlin, Niklas LU ; Rehnberg, Nicola LU orcid and Zhang, Baozhong LU (2024) In Reactive and Functional Polymers 205.
Abstract
There is currently intensive research on the development of biobased
polymers as potential alternatives to the environmentally hazardous
isocyanate-based polyurethanes. In this context, polythioureas (PTUs)
form a particularly attractive target because they can be synthesized by
using isothiocyanates, a class of molecules that can be found in nature
with expected low toxicity. Herein, a series of 16 PTUs with varied
chemical structures, mostly being new polymers, have been synthesized
and their possible chemical recycling pathways via thermally induced and
acid-catalyzed depolymerizations have been investigated. The obtained
PTUs showed a varied range of molecular weights (up to Mn ∼... (More)
There is currently intensive research on the development of biobased
polymers as potential alternatives to the environmentally hazardous
isocyanate-based polyurethanes. In this context, polythioureas (PTUs)
form a particularly attractive target because they can be synthesized by
using isothiocyanates, a class of molecules that can be found in nature
with expected low toxicity. Herein, a series of 16 PTUs with varied
chemical structures, mostly being new polymers, have been synthesized
and their possible chemical recycling pathways via thermally induced and
acid-catalyzed depolymerizations have been investigated. The obtained
PTUs showed a varied range of molecular weights (up to Mn ∼ 69.5 kDa), intrinsic viscosity (up to ∼6 dL/g), and glass transition temperatures (Tg ∼ 59–128 °C).
Notably, we observed that the presence of aromatic segments lowered the
thermal stability of the polymers, so they were generally easier to
depolymerize (compared to those without aromatic groups), forming
oligomers with controlled end-groups (i.e. telechelic polymers) that
could be repolymerized. The obtained aliphatic PTUs were generally
resistant against thermochemical depolymerizations, but they could be
effectively depolymerized by sulfuric acid. The repolymerization methods
depended on the end groups of the depolymerized products, which in this
work included direct repolymerization of polythioureas (if the end
groups contain ∼1:1 of isothiocyanates and amines) and copolymerizations
with another monomer terephthaldehyde (if the end groups contain only
amines). Our results provided a first comprehensive molecular insight
into the synthetic and recycling possibilities of using isothiocyanates
and polythioureas in the exploration of potential alternatives for
isocyanates and polyurethanes. (Less)
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author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Reactive and Functional Polymers
volume
205
article number
106062
pages
12 pages
publisher
Elsevier
external identifiers
  • scopus:85205470493
ISSN
1873-166X
DOI
10.1016/j.reactfunctpolym.2024.106062
language
English
LU publication?
yes
id
6b6d3159-15cb-463f-b663-067c70c4c6cd
date added to LUP
2024-11-21 09:18:42
date last changed
2025-04-04 14:52:28
@article{6b6d3159-15cb-463f-b663-067c70c4c6cd,
  abstract     = {{There is currently intensive research on the development of biobased <br>
polymers as potential alternatives to the environmentally hazardous <br>
isocyanate-based polyurethanes. In this context, polythioureas (PTUs) <br>
form a particularly attractive target because they can be synthesized by<br>
 using isothiocyanates, a class of molecules that can be found in nature<br>
 with expected low toxicity. Herein, a series of 16 PTUs with varied <br>
chemical structures, mostly being new polymers, have been synthesized <br>
and their possible chemical recycling pathways via thermally induced and<br>
 acid-catalyzed depolymerizations have been investigated. The obtained <br>
PTUs showed a varied range of molecular weights (up to M<sub>n</sub> ∼ 69.5 kDa), intrinsic viscosity (up to ∼6 dL/g), and glass transition temperatures (T<sub>g</sub> ∼ 59–128 °C).<br>
 Notably, we observed that the presence of aromatic segments lowered the<br>
 thermal stability of the polymers, so they were generally easier to <br>
depolymerize (compared to those without aromatic groups), forming <br>
oligomers with controlled end-groups (i.e. telechelic polymers) that <br>
could be repolymerized. The obtained aliphatic PTUs were generally <br>
resistant against thermochemical depolymerizations, but they could be <br>
effectively depolymerized by sulfuric acid. The repolymerization methods<br>
 depended on the end groups of the depolymerized products, which in this<br>
 work included direct repolymerization of polythioureas (if the end <br>
groups contain ∼1:1 of isothiocyanates and amines) and copolymerizations<br>
 with another monomer terephthaldehyde (if the end groups contain only <br>
amines). Our results provided a first comprehensive molecular insight <br>
into the synthetic and recycling possibilities of using isothiocyanates <br>
and polythioureas in the exploration of potential alternatives for <br>
isocyanates and polyurethanes.}},
  author       = {{de Menezes, Rafael N.L. and Gordivska, Olga and Nguyen, Tran Tam and Warlin, Niklas and Rehnberg, Nicola and Zhang, Baozhong}},
  issn         = {{1873-166X}},
  language     = {{eng}},
  publisher    = {{Elsevier}},
  series       = {{Reactive and Functional Polymers}},
  title        = {{Synthesis and chemical recycling investigations of polythioureas}},
  url          = {{http://dx.doi.org/10.1016/j.reactfunctpolym.2024.106062}},
  doi          = {{10.1016/j.reactfunctpolym.2024.106062}},
  volume       = {{205}},
  year         = {{2024}},
}