Acetone & Graphite Epoxy Composites

Acetone content in high and low on the electrical properties of sony VGP-BPS15/S , sony VGP-BPS18 epoxy-Graphite Composites great impact. Recent Huaqiao University School of Materials Science and Engineering to study the diluent acetone. Addition on the resistivity of composite materials to design a set of experimental research. According to the China Association epoxy resin (www.epoxy-e.cn) experts, the experimental manipulation in the incubator temperature to reduce viscosity of epoxy resin to spread the filling instead of using the thinner, this preparation method is conducive to composite materials receive a lower resistivity and better structural performance, the success of the experiment was not only a lower resistivity and a smooth curing, the sample apparent structural performance are better, showing that the presence of acetone, the samples not only increases the resistivity, but also affect the structure and properties of the samples, and even difficult to cure the sample.

Heat and add diluent can make a better dispersed epoxy filler, it is because they are able to substantially reduce the viscosity of epoxy resin, according to documents can be projected E-44 Bisphenol A type epoxy resin heating up and adding acetone viscosity when it is the general situation: E-44 Bisphenol A type epoxy resin at 25 ℃ viscosity of about 25 Pa · s, the viscosity of acetone at 20 ℃ for 0.316mPa · s; 100 ℃ when the E-44 viscosity of bisphenol-type sony VGP-BPS19 , sony VGP-AC19V10 epoxy resin to about 0.1Pa · s or so; 25 ℃ when the E-44 Bisphenol A type epoxy resin viscosity should be reduced to 0.1Pa · s, is about to add 40% mass fraction of acetone; 25 ℃ below to add more acetone can the viscosity dropped to 0.1Pa · s. The viscosity of epoxy resin can be seen on the temperature sensitivity of large, small changes in temperature will cause great changes in viscosity. In the dispersed filler on the heat to reduce viscosity of epoxy instead of adding diluent is feasible.

Well-known non-reactive diluent to join, make cured epoxy resin strength and modulus decreased, but the elongation rates were rising. In the amount came from a structure and properties of the cured compound has little effect is large amount of the performance of cured material will deteriorate, while causing increased contractility and decreased adhesion is generally non-reactive diluent additive amount shall not exceed 15%. According to the China Association epoxy resin (www.epoxy-e.cn) experts, with the added amount of acetone and ethylenediamine excess amount of curing agent increased, the sample become soft, adhesiveness variation until the paste is difficult to maintain curing . This is because the thinner the presence of epoxy resin crosslinking density decrease, and the thinner their mechanical strength is weak, so when the amount of sony VGP-AC19V13 , sony VGP-AC19V19 larger thinner cured compound properties deteriorate. More than a certain amount of time and even bring down the crosslinking density of epoxy resin can not establish a curing structural system, as well as can not be cured only one batter. From the above analysis can be seen in relation to the use of thinner, epoxy filler temperature to spread on the structure and properties of epoxy composite materials is beneficial.

About thinner acetone addition on the resistivity of composite materials, with the growing amount of acetone added, the resistivity of composite materials is increasing, the amount of acetone to join when there are fewer materials, the resistivity of slower rise , while the added amount of acetone larger resistivity of the material rise faster. China Epoxy Resin Industry Association (www.epoxy-e.cn), experts say by adding acetone led to increased resistivity is due to increase in the amount of added acetone, so that composite system size increases, the graphite content is relatively lower, resulting in higher resistivity of composite system. But this can only partly explain the amount of acetone, adding the impact of the resistivity of the material can not fully sony VGP-BPL11 , sony VGP-BPL12 explain the experimental results. Because the resistivity is not with the added amount of acetone linearly increased, but when there are fewer resistivity by adding acetone increased slowly, by adding acetone increased more rapidly when the resistivity. This non-linear changes are shown the characteristics of polymer composite conductive material, the kinds of material is essentially a network of conductive pattern.

Epoxy resin, graphite, ethylene diamine, acetone as a complex system, not occurred in the epoxy curing, is a multi-phase homogeneous mixture. According to the China Association epoxy resin (www.epoxy-e.cn) experts, after the occurrence of curing reaction of epoxy resin, epoxy resin and ethylenediamine reaction to the gradual formation of a cured network, in every local area, acetone and the ring epoxy resin, ethylenediamine divisive. In the small amount of acetone, the acetone in the network and graphite epoxy curing between the small number of conductive material to cut off the network, it is a three-dimensional network conduction mode, less cut off part of the electrical conductivity of the material as a whole had little impact so resistivity to rise only slowly sony VGP-BPL13 , sony VGP-BPL14. In acetone by adding the amount is large, with the epoxy curing network separation of acetone, in all pushed to the local area around the graphite micro-chip, micro-chip formation of graphite wrapped state, so a large number of conductive network is cut off, so material resistance rates rose sharply.