Effects of Water Absorption on Impact Value of Aluminum Dispersed Composite Nylon6

Abstract

Composite polymers, which are nylon6 materials with aluminum powders dispersed homogeneously, are prepared. Influences of water absorption on Charpy impact value of composite polymers have been investigated. Although the aluminum dispersion from zero to 40 vol%Al decreases the impact value, the water absorbing treatment for 10 5 s at boiling point largely increases the impact values of all composite polymers. It is explained that water molecules in nylon6 mainly relaxes the impact force. If the water absorption also enhances the interfacial energy to form the crack in nylon6 and its composites, the high impact value with smooth undulating surface can be explained.

High Electric Conductive PMMA Composites without Impact Value Decay by Dispersion of Copper Powder

“…Although the addition from 20 to 30 vol%Cu powder reduces the impact value from 6 to 3 kJm À2 , the impact values of the high electric conductive ABS-Cu composites with 20 to 30 vol%Cu is approximately 7 kJm À2 and is apparently higher than that of N6-Al composites (2 kJm À2 ) for use with practical exteriors in Japan. [1][2][3] The modulated impact value is higher than that of nylon6 composites with Al dispersion from 20 to 30 vol%.…”

“…3,10) Since the interfacial adhesive strength (attractive force) between aluminum and nylon6 is not due to chemical bonding and thus is not so large, the addition of 10 vol%Cu and Al in ABS and nylon6 converts the type of fracture from ductile matrix fracture to weakly bonded interfacial fracture between metal and polymer. 3,10) On the other hand, the addition of 10 vol%Cu slightly raises the impact value of solution casted PMMA polymer. The impact value is independent to the Cu addition, when the weak strength of polymer molecules in PMMA is approximately equal to the interfacial adhesive strength (attractive force) between copper and PMMA polymer.…”

“…3) For practical articles, the impact value of the electric conductive composites is critical. The addition of Al powder gradually reduces the impact value of nylon6.…”

“…However, the low impact value induced by the powder dispersion is a serious problem, because cracks easily propagate at the interface between nylon6 matrix and Al powders. 2,3) Both appropriate impact value and appropriate electric conductivity of copper powders ABS composites (ABS-Cu) have been found. 10) However, it is a serious problem for Cu addition to decrease the impact value of the high electric conductive composites in a predictable manner.…”

“…[1][2][3] The addition of electric conductive powders has enhanced the electric conductivity of insulators. Based on the percolation theory, 4,5) the critical volume fraction (threshold) from the insulator to the electric conductor is 16 AE 2 vol% in powder dispersed composites.…”