TY - JOUR
T1 - Synthesis of melt-stable and semi-crystalline poly(1,4-dioxan-2-one) by ring-opening (co)polymerisation of 1,4-dioxan-2-one with different lactones
AU - Raquez, Jean Marie
AU - Degée, Philippe
AU - Narayan, Ramani
AU - Dubois, Philippe
PY - 2004/10/1
Y1 - 2004/10/1
N2 - High molecular weight poly(1,4-dioxan-2-one) (PPDX) can be readily synthesized by catalysed ring-opening polymerisation of 1,4-dioxan-2-one (PDX) using aluminium trialkoxide active species as initiator. Even though the resulting poly(ester-alt-ether) chains display good thermo-mechanical properties, they suffer from low thermal stability. PPDX is known to thermally degrade mainly through unzipping depolymerisation promoted from the hydroxyl end-groups and yielding PDX monomer. To overcome this drawback, chemical modification of the PPDX hydroxyl end-groups was first attempted with trichloroacetyl isocyanate; however, with limited success in terms of thermal stability. Interestingly, it has been shown that the copolymerisation of PDX with tiny amounts of lactones like ε-caprolactone (CL) and δ-valerolactone (VL), is an efficient way to enhance the thermal stability of the resulting polyester chains without significantly compromising the crystallinity and melting temperature of PPDX. The thermal stability of the resulting polyester chains was studied by isothermal TGA under inert atmosphere as well as under air. For instance, when PDX was copolymerised with a low amount of CL by initiation with Al(OiPr)3 at 100°C in bulk, a melt-stable copolymer was rapidly formed with a composition close to the starting feed and a multiblock-like structure as shown by 1H and 13C NMR spectroscopy. The incorporation of 3-15 wt% of CL into PPDX chains substantially increases the thermal stability of resulting PPDX-rich copolyesters, while preserving a high melting temperature ranging between 90 and 100°C. Furthermore, an interesting internal plasticising effect is also detected by DSC with the glass transition temperature decreasing from, e.g., -10 to -22°C in the presence of 14 wt% CL copolymerised in the PPDX chains.
AB - High molecular weight poly(1,4-dioxan-2-one) (PPDX) can be readily synthesized by catalysed ring-opening polymerisation of 1,4-dioxan-2-one (PDX) using aluminium trialkoxide active species as initiator. Even though the resulting poly(ester-alt-ether) chains display good thermo-mechanical properties, they suffer from low thermal stability. PPDX is known to thermally degrade mainly through unzipping depolymerisation promoted from the hydroxyl end-groups and yielding PDX monomer. To overcome this drawback, chemical modification of the PPDX hydroxyl end-groups was first attempted with trichloroacetyl isocyanate; however, with limited success in terms of thermal stability. Interestingly, it has been shown that the copolymerisation of PDX with tiny amounts of lactones like ε-caprolactone (CL) and δ-valerolactone (VL), is an efficient way to enhance the thermal stability of the resulting polyester chains without significantly compromising the crystallinity and melting temperature of PPDX. The thermal stability of the resulting polyester chains was studied by isothermal TGA under inert atmosphere as well as under air. For instance, when PDX was copolymerised with a low amount of CL by initiation with Al(OiPr)3 at 100°C in bulk, a melt-stable copolymer was rapidly formed with a composition close to the starting feed and a multiblock-like structure as shown by 1H and 13C NMR spectroscopy. The incorporation of 3-15 wt% of CL into PPDX chains substantially increases the thermal stability of resulting PPDX-rich copolyesters, while preserving a high melting temperature ranging between 90 and 100°C. Furthermore, an interesting internal plasticising effect is also detected by DSC with the glass transition temperature decreasing from, e.g., -10 to -22°C in the presence of 14 wt% CL copolymerised in the PPDX chains.
KW - Aliphatic polyester
KW - Copolymerisation
KW - Lactones
KW - Poly(1,4-dioxan-2-one)
KW - Ring-opening polymerisation
KW - Thermal stability
UR - http://www.scopus.com/inward/record.url?scp=4544309442&partnerID=8YFLogxK
U2 - 10.1016/j.polymdegradstab.2004.04.007
DO - 10.1016/j.polymdegradstab.2004.04.007
M3 - Article
AN - SCOPUS:4544309442
SN - 0141-3910
VL - 86
SP - 159
EP - 169
JO - Polymer Degradation and Stability
JF - Polymer Degradation and Stability
IS - 1
ER -