The dynamic mechanical properties of wood powder/polypropylene composites with different wood content treated and untreated with the compatibilizer have been studied. It has been found that addition of wood powders an...The dynamic mechanical properties of wood powder/polypropylene composites with different wood content treated and untreated with the compatibilizer have been studied. It has been found that addition of wood powders and the compatibilizer can both improve the viscoelasticity of composites. Glass transition temperature (Tg) of appropriate wood powder-filled composites decreased. The value for the storage modulus (G') increased gradually with increasing wood powder content. The addition of the compatibiliz...展开更多
Aluminate-based coupling agent was added as a compatibilizer to make the chemical modification of wood powder. The mechanical properties and morphology of wood powder/polypropylene composites were studied. The results...Aluminate-based coupling agent was added as a compatibilizer to make the chemical modification of wood powder. The mechanical properties and morphology of wood powder/polypropylene composites were studied. The results showed that the compatibilizer can increase the impact strength of the wood/polypropylene composites, but it has a slightly negative effect on the tensile and flexural strength. For dynamic mechanical properties and Differential Scanning Calorimetry, Aluminate-based coupling agent can slightly increase the storage modulus and loss modulus, and decrease the melt point and the Calorie of Melt. Scanning electron microscopy showed that Aluminate-based coupling agent had a stronger affinity between the wood and polypropylene surfaces. These results suggested that Aluminate-based coupling agent may play a useful role in improving wood powder/polypropylene composites properties.展开更多
Viscoelastic properties of maleated polypropylene （MAPP）-modified wood flour/polypropylene composites （WPC） were investigated by both a compression stress relaxation method and dynamic mechanical analyses （DMA）....Viscoelastic properties of maleated polypropylene （MAPP）-modified wood flour/polypropylene composites （WPC） were investigated by both a compression stress relaxation method and dynamic mechanical analyses （DMA）. Three wood to polymer ratios （40：60, 60：40, and 80：20） and five MAPP loading levels （0, 1, 2, 4 and 8%） were used to study their effects on the viscoelastic prop- erties of MAPP-WPC. The results show that： 1） higher wood to polymer ratio corresponds to higher stress relaxation levels for unmodified WPC. The modification with MAPP has an obvious effect on the stress relaxation of MAPP-WPC at higher wood to polymer ratios （60：40 and 80：20）, but almost no effect at the 40：60 wood to polymer ratio. The optimal MAPP loading level for the wood to polymer ratio of 60：40 appears at 1%; 2） the storage modulus reaches its maximum at a MAPP loading level of 1% for wood to polymer ratios of 40：60 and 60：40, while for the 80：20 wood to polymer ratio, a higher storage modulus is observed at higher MAPP loading levels, which is quite consistent with the stress relaxation results. The results suggested that a suitable loading level of MAPP has a positive effect on the viscoelastic properties of WPC at higher wood to polymer ratios. Excessive MAPP loading would have resulted in adverse effects.展开更多
The effect of wood species (Chinese fir and Poplar), wood fiber content (10%, 25%, 40%) and wood fiber sizes (16 to 32 mesh, 32-65 mesh, above 65 mesh) on the properties of the wood fiber-Polypropylene composites were...The effect of wood species (Chinese fir and Poplar), wood fiber content (10%, 25%, 40%) and wood fiber sizes (16 to 32 mesh, 32-65 mesh, above 65 mesh) on the properties of the wood fiber-Polypropylene composites were studied in this paper. The results indicate that the effect of wood fiber content and size in composite were more important than that of chosen wood species. Compared with polypropylene without wood fiber, the flexural strength of the composites increased when adding wood fiber into polypr...展开更多
文摘The dynamic mechanical properties of wood powder/polypropylene composites with different wood content treated and untreated with the compatibilizer have been studied. It has been found that addition of wood powders and the compatibilizer can both improve the viscoelasticity of composites. Glass transition temperature (Tg) of appropriate wood powder-filled composites decreased. The value for the storage modulus (G') increased gradually with increasing wood powder content. The addition of the compatibiliz...
基金This study was supported by Introduce Foreign Advanced Technology Project (2001-1).
文摘Aluminate-based coupling agent was added as a compatibilizer to make the chemical modification of wood powder. The mechanical properties and morphology of wood powder/polypropylene composites were studied. The results showed that the compatibilizer can increase the impact strength of the wood/polypropylene composites, but it has a slightly negative effect on the tensile and flexural strength. For dynamic mechanical properties and Differential Scanning Calorimetry, Aluminate-based coupling agent can slightly increase the storage modulus and loss modulus, and decrease the melt point and the Calorie of Melt. Scanning electron microscopy showed that Aluminate-based coupling agent had a stronger affinity between the wood and polypropylene surfaces. These results suggested that Aluminate-based coupling agent may play a useful role in improving wood powder/polypropylene composites properties.
基金supported by the National Natural Science Foundation of China (Grant No. 30871966)
文摘Viscoelastic properties of maleated polypropylene （MAPP）-modified wood flour/polypropylene composites （WPC） were investigated by both a compression stress relaxation method and dynamic mechanical analyses （DMA）. Three wood to polymer ratios （40：60, 60：40, and 80：20） and five MAPP loading levels （0, 1, 2, 4 and 8%） were used to study their effects on the viscoelastic prop- erties of MAPP-WPC. The results show that： 1） higher wood to polymer ratio corresponds to higher stress relaxation levels for unmodified WPC. The modification with MAPP has an obvious effect on the stress relaxation of MAPP-WPC at higher wood to polymer ratios （60：40 and 80：20）, but almost no effect at the 40：60 wood to polymer ratio. The optimal MAPP loading level for the wood to polymer ratio of 60：40 appears at 1%; 2） the storage modulus reaches its maximum at a MAPP loading level of 1% for wood to polymer ratios of 40：60 and 60：40, while for the 80：20 wood to polymer ratio, a higher storage modulus is observed at higher MAPP loading levels, which is quite consistent with the stress relaxation results. The results suggested that a suitable loading level of MAPP has a positive effect on the viscoelastic properties of WPC at higher wood to polymer ratios. Excessive MAPP loading would have resulted in adverse effects.
文摘The effect of wood species (Chinese fir and Poplar), wood fiber content (10%, 25%, 40%) and wood fiber sizes (16 to 32 mesh, 32-65 mesh, above 65 mesh) on the properties of the wood fiber-Polypropylene composites were studied in this paper. The results indicate that the effect of wood fiber content and size in composite were more important than that of chosen wood species. Compared with polypropylene without wood fiber, the flexural strength of the composites increased when adding wood fiber into polypr...
