Effects of Chemical Foaming Agents on the Physico-Mechanical Properties and Rheological Behavior of Bamboo Powder-Polypropylene Foamed Composites

Abstract

To make full use of bamboo resources in China and explore the foaming mechanism of bamboo powder-polypropylene (PP) foamed composites, a foamed composite of 54 wt% PP and 13 wt% HMSPP containing 33 wt% bamboo powder blends was prepared by injection moulding. Effects of chemical foaming agents (CFA) on the mechanical properties and rheological behavior of foamed composites were investigated. The mechanical measurements and ESEM test results indicated that the composite with 1% modified exothermic FA had smaller cell size and better cell distribution compared with endothermic FA. It also had better physico-mechanical properties, with a decrease of 14.2% in density and an increase of 16.8% to 40.2% in the specific tensile, bending, and notched impact strength compared with the non-foamed composite. The frequency sweep results indicated that all composites had a shearthinning behavior, and both the modulus and complex viscosity of composite with 1% exothermic FA decreased compared with those of the non-foamed composite. The shear rate scans revealed that the non-Newtonian fluid index increased with the increase of exothermic FA content. The viscous activation energy of the modified composite with 1% exothermic FA was 46.41KJ•mol -1 . This was an increase of 8.9% compared with that of the non-foamed analogue.

Effects of Maleic Anhydride-Grafted Polypropylene (MAPP) on the Physico-Mechanical Properties and Rheological Behavior of Bamboo Powder-Polypropylene Foamed Composites

“…The density of 9% MAPP-treated composite decreased to 0.845 g/cm 3 , which is an decrease of 15% compared with that of the unfoamed composite (0.994 g/cm 3 ) (Zhou et al 2012). Also the flexural modulus and the specific flexural, tensile, and notched impact strengths of 9% MAPP-treated composite reached maximum values of 2.91 GPa, 47.59 MPa, 26.60 MPa, and 7.45 KJ/m 2 , respectively, yielding improvements of 6.0%, 22.9%, 29.6%, and 49.0%, respectively, compared to the untreated composite.…”

“…Finally, the FA and BP/PP granules were mixed, and foamed samples were prepared using an injection machine at a melting temperature of 160 to 190 °C, a mould temperature of 90 °C, an injection pressure of 5 to 6 MPa, a packing pressure of 4 MPa, and a packing time of 10 s. The PP accounted for 53 wt%, the HMSPP accounted for 13 wt%, the BP accounted for 33 wt%, and the FA accounted for 1 wt% of the foamed composites. This ratio was used because previous studies reported that the comprehensive mechanical properties of foamed composites were best when the amount of BP was 33 wt% (Zhou et al 2012).…”

Effects of maleic anhydride content on mechanical properties of carbon fibers-reinforced maleic anhydride-grafted-poly-propylene matrix composites

“…These results can be thinkable that the K IC value decreased were indicates that the surface of PP were covered with excessive MA may form a weak layer resulting in decrease in interfacial adhesion due to the formation of new weak interface between the carbon fiber and matrices. Furthermore adding redundant MA may cause increased radical depolymerization of the PP molecule chains, thereby leading to the reduction of the mechanical properties [38]. In addition, theoretical calculations have the oxyfluorinated carbon fibers/PP composites have a higher work of adhesion than that of the other composites.…”

Interfacial Characterization and Optimal Preparation of Novel Bamboo Plastic Composite Engineering Materials

“…For the latter, the renewable, inexpensive, biocompatible characteristics, and desirable performance have allowed natural fibers to gain more impetus (Saba et al 2015). Despite a lower density, a content of over 60 wt% cellulose (Young's modulus 140 to 250 GPa) endows natural fiber with 6 to 80 GPa modulus, which is comparable to glass fibers (Yeh aspect ratio (than pine), a higher strength to weight ratio (than concrete, timber, and steel), and good wear resistance among the natural fibers (Huda et al 2012;Li et al 2012;Zhou et al 2012). Furthermore, bamboo contains 60 wt% cellulose, with a smaller microfibrillar angle of 2 to 10°, thereby facilitating matrix reinforcement (Abdul Khalil et al 2012).…”

“…Finally, bamboo fiber is about 10 times cheaper than glass fiber (Huda et al 2012). Unfortunately, under the current processing capacity of China, over 60 wt% of bamboo would become residue such as flour (whose units suffer greater damage and are different from general fiber), thus posing a threat to the environment (Zhou et al 2012). Similarly, HDPE is a major product of the Chinese chemical industry and serves as a commonly-used matrix of polymer composite and key source of white pollution (Du et al 2014;Fang et al 2014;Li et al 2014;Ren et al 2014).…”