Spontaneous Crosslinking of Poly(1,5-dioxepan-2-one) Originating from Ether Bond Fragmentation

• The spontaneous reaction of unsaturated double bonds induced by the fragmentation of ether bonds is presented as a method to obtain a crosslinked polymer material. Poly(1,5-dioxepan-2-one) (PDXO) was synthesized using three different polymerization techniques to investigate the influence of the synthesis conditions on the ether bond fragmentation. It was found that thermal fragmentation of the ether bonds in the polymer main chain occurred when the synthesis temperature was 140 degrees C or higher. The double bonds produced reacted spontaneously to form cross-links between the polymer chains. The formation of a network structure was confirmed by Fourier transform infrared spectrometry and differential scanning calorimetry. In addition, the low molar mass species released during hydrolysis of the DXO polymers were monitored by ESI-MS and MALDI-TOF-MS. Ether bond fragmentation also occurred during the ionization in the electrospray instrument, but predominantly in the lower mass region. No fragmentation took place during MALDI ionization, but it was possible to detect water-soluble DXO oligomers with a molar mass up to approximately 5000 g/mol. The results show that ether bond fragmentation can be used to form a network structure of PDXO.

Subject headings

NATURVETENSKAP  -- Kemi -- Polymerkemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Polymer Chemistry (hsv//eng)

Keyword

crosslinking

degradation

mass spectrometry

polyester-ethers

ring-opening polymerization

ring-opening polymerization

collision-induced dissociation

degradation-product patterns

ionization mass-spectrometry

epsilon-caprolactone

l-lactide

block-copolymers

1

5-dioxepan-2-one

hydrophilicity

polyglycols

Polymer chemistry

Polymerkemi

Publication and Content Type

ref (subject category)

art (subject category)