QIBEBT Develops a Novel Branched Polyoxymethylene with Excellent Thermal stability
Polyoxymethylene (POM) is widely used as a traditional metal substitute due to its high crystallinity, and excellent tensile, impact, and compression strength since its discovery as early as 1920s. Although POM currently derives from fossil fuel methanol, POM is poised to become increasingly attractive because methanol can be synthesized from biorenewable (wood, agricultural waste) feedstocks, hence POM could be considered as renewable engineering plastics. However, because of the thermal instability of hemiacetal groups at the polymer chain ends, the thermal stability of POM was always at the center of the research. A common method that has been industrialized is by copolymerizing with cyclic monomers. Unfortunately，the performance of the patent technologies of POM, such as the high thermal stability of acetal copolymer, mostly was monopolized by foreign firms such as Dupont.
Recently, a novel POM copolymer of 1,3,5-trioxane (TOX) with 3-(alkoxymethyl)-3-ethyloxetane (ROX) was prepared by Bio-inspired Polymers and Functional Materials Group at Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences. Although a huge number of papers and patents have been devoted to the copolymerization of various of cyclic monomers with TOX, there are only few patents on the synthesis of copolymer of TOX and oxetane derivatives. Professor WAN Xiaobo and his colleagues systematically studied the influence of the incorporate ratio of oxetanes and the length of alkyl sidechain on the oxetanes on the thermomechainal properties of the resulant copolymers. High incorporation ratio of ROX (up to 20%) into the copolymer was obtained. Of all the copolymers, P(TOX-co-EOX)s show the lowest melting temperature and the best thermal stability ( a 70 oC increase of the decomposition temperature(Figure 1) than POM homopolymer). The work is published in a recent Macromolecular Chemistry and Physics.
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Figure 1. DSC and TGAcurves of P(TOX-co-EOX) and HOPOM (Image by Prof. WAN’s group) |
The investigation of the mechanism of the copolymerization is still under way in Prof. WAN’s laboratory and they also plan to increase the thermal stability of the copolymer by end-capping process. This technology might be applicable for large-scale synthesis of POM copolymers.
Reference:
http://onlinelibrary.wiley.com/doi/10.1002/macp.201300473/abstract
Contact:
Prof . Dr. WAN Xiaobo
Email: wanxb (AT) qibebt.ac.cn
TEL: 0532-80662740, 0532-80662741
