No abstract

Acrylonitrile-butadiene-styrene (ABS) was treated with various formulations containing an intumescent fire retardant, which consists of ammonium polyphosphate (APP) and a novel char-forming agent, poly(diphenolic phenyl phosphate)(poly(DPA-PDCP)). The behaviour of this intumescent system was investigated by thermogravimetric analysis (TGA), LOI test and cone calorimeter test, respectively. The results showed that the addition of poly(DPA-PDCP) enhanced the thermal stability and flame retardancy of ABS/APP. The weight of residues improved with the addition of poly(DPA-PDCP) . SEM investigations of residual char burning after cone calorimeter test revealed that poly(DPA-PDCP) plays an stimulative role in the process of carbonization. The intumescent chars formed from ABS/APP/ poly(DPA-PDCP) composites were intact and strong. It is confirmed that the poly(DPA-PDCP) is an efficient char-forming agent for flame retardant ABS resin.

Due to influence by many factors like soil classification, viscosity property and vibration frequency, there is no common view yet about the effect of frequency on dynamic pore pressure and characteristics. In order to study the development of pore pressure, strain and dynamic strength of Hangzhou Bay undisturbed structural silty clay under different vibration frequencies, cyclic triaxial tests were performed. The test results indicate that the frequency has little influence on pore pressure and strain when they didn’t reach the threshold values, but once they exceeded the threshold values the frequency will has strong influence. There is critical cyclic stress ratio when the cyclic stress ratio has not reached that value, the frequency has no influence on dynamic strength. For the given cycles, the higher the frequency is, the bigger the dynamic strength is. And with the increment of frequency, the influence on dynamic is decreased eventually.