Simultaneously reinforcing and toughening of poly(propylene carbonate) by epoxy-terminated hyperbranched polymer(EHBP) through micro-crosslinking
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In order to improve the mechanical properties of PPC, a hyperbranched polymer with a large number of active epoxy groups at the end (epoxy-terminated hyperbranched polyester, EHBP) was synthesized and characterized by FTIR, NMR and GPC. Then, PPC/EHBP blends were prepared through melt-mixing. The effect of EHBP on the mechanical properties, thermal properties, viscosity and gas permeability of the PPC/EHBP blends is studied in detail based on the expected micro-crosslinking theory between EHBP and PPC. The results indicate that when the content of EHBP is 0.5 wt%, the tensile strength increased by 73.8%; elongation at break increased by 131.7%; the impact strength increased by 88.4%. The glass transition temperature increased from 40.71 to 44.44 °C upon addition of EHBP. Also, the addition of EHBP is beneficial to the improvement of the gas barrier property of PPC. The modification mechanism is discussed. It indicates that upon addition of EHBP, both physical hydrogen bonding and chemical bonding occurred, based on gel content calculation, which is in line with expectations. When the content of EHBP is 0.5 wt%, the degree of chemical micro-crosslinking is about 9.2%.
KeywordsEHBP PPC Modification
The authors thank the National Nature Science Foundation (51503007), Support Project of High-level Teachers in Beijing Municipal Universities in the Period of 13th Five-year Plan (CIT&TCD201804030) and Beijing Municipal Natural Science Fund-Key project of science and technology plan of Beijing Education Committee (KZ201810011017) for financial support.
- 1.Stewart R (2007) Biopolymers—greater consumer awareness drives growth of biobased-resins market. Plast Eng 63:24Google Scholar
- 3.Nakano K, Hashimoto S, Nakamura M, Kamada T, Nozaki K (2011) Stereocomplex of poly(propylene carbonate): synthesis of stereogradient poly(propylene carbonate) by regio- and enantioselective copolymerization of propylene oxide with carbon dioxide. Angew Chem Int Edit 50:4868–4871CrossRefGoogle Scholar
- 14.Pang S, Xu N, Xu G, Pan L, Lin Q, Wang X (2013) Preparation and properties of 4,4-diphenylmethane diisocyanate blocking modified poly(propylene carbonate). J Appl Polym Sci 128:2020–2029Google Scholar
- 27.Tang B, Liu X, Zhao X, Zhang J (2014) Highly efficient in situ toughening of epoxy thermosets with reactive hyperbranched polyurethane. J Appl Polym Sci 131:40614Google Scholar