Polylactide(PLA)bead foams show a high potential regarding their applicability in packaging or consumer products.Concerning the comparable properties of PLA to Polystyrene(PS)and the good CO_(2) footprint it represent...Polylactide(PLA)bead foams show a high potential regarding their applicability in packaging or consumer products.Concerning the comparable properties of PLA to Polystyrene(PS)and the good CO_(2) footprint it represents a potential alternative to petroleum-based polymer foams.However,foaming of PLA is challenging,due to its low melt strength,therefore chemical modifiers are often used.Concerning the bead foam technology regarding PLA,the available literature is limited so far.Within this study,the bead foaming behavior of neat and modified amorphous PLA was investigated.The material was modified by talc and an epoxy-based chain extender.These compounds have been investigated regarding their sorption behavior in CO_(2) atmosphere and their foaming behavior.Foaming was conducted by using the batch foaming method based on a rapid temperature increase after saturation with CO_(2).In order to achieve welded bead foams,a one-step processing for foaming and welding has been established.Finally,the compression properties of the PLA bead foams have been investigated.Densities below 50 kg/m^(3) for single bead foams and 80 kg/m^(3) for molded foams were achieved,respectively.展开更多
The compressive mechanical properties of syntactic foams reinforced by hollow plastic beads were studied by the quasi-static compression test. The failure mechanism of syntactic foams was also investigated by macrosco...The compressive mechanical properties of syntactic foams reinforced by hollow plastic beads were studied by the quasi-static compression test. The failure mechanism of syntactic foams was also investigated by macroscopic and microscopic observation on the fractured specimens. The experimental results show that the density of syntactic foams is still the key factor affecting their mechanical properties. The macroscopic and microscopic observation on the fractured specimens indicates that the main failure mode is the elastic-plastic collapse caused by shear.展开更多
基金funded by German Research Foundation(DFG),Grant No.AL474/34-1Open access charges were funded by the German Research Foundation(DFG)and the University of Bayreuth in the funding program Open Access Publishing.
文摘Polylactide(PLA)bead foams show a high potential regarding their applicability in packaging or consumer products.Concerning the comparable properties of PLA to Polystyrene(PS)and the good CO_(2) footprint it represents a potential alternative to petroleum-based polymer foams.However,foaming of PLA is challenging,due to its low melt strength,therefore chemical modifiers are often used.Concerning the bead foam technology regarding PLA,the available literature is limited so far.Within this study,the bead foaming behavior of neat and modified amorphous PLA was investigated.The material was modified by talc and an epoxy-based chain extender.These compounds have been investigated regarding their sorption behavior in CO_(2) atmosphere and their foaming behavior.Foaming was conducted by using the batch foaming method based on a rapid temperature increase after saturation with CO_(2).In order to achieve welded bead foams,a one-step processing for foaming and welding has been established.Finally,the compression properties of the PLA bead foams have been investigated.Densities below 50 kg/m^(3) for single bead foams and 80 kg/m^(3) for molded foams were achieved,respectively.
基金the National Natural Science Foundation of China(No. 50473013)
文摘The compressive mechanical properties of syntactic foams reinforced by hollow plastic beads were studied by the quasi-static compression test. The failure mechanism of syntactic foams was also investigated by macroscopic and microscopic observation on the fractured specimens. The experimental results show that the density of syntactic foams is still the key factor affecting their mechanical properties. The macroscopic and microscopic observation on the fractured specimens indicates that the main failure mode is the elastic-plastic collapse caused by shear.
