| Inertial confinement fusion(ICF)experiment is one of the main ways to use the nuclear energy controllably so far.The GDP microspheres served as a fuel container are widely used in the ICF physical experiments.The degradable mandrel technique is the basis of the preparation of GDP microspheres.The targets fabricated by the degradable mandrel technique have the properties with high sphericity and well surface finish.Due to the good balling performance,good mechanical properties,low degradation temperature and the entire degradation of the PAMS is selected as the materials to fabricate the mandrel.The qualities of the GDP microspheres are influenced by the good balling performance and the properties of thermal degradation for PAMS.So,the effects on the balling performance and thermal degradation properties of PAMS are investigated in this work.The main research contents as follows:(1)The qualities of GDP shells are influenced by the thermal degradation temperature and degradation rate of PAMS.Usually,the free radical can reduce the thermal degradation temperature of the polymer and change the thermal degradation rate.This paper studies the influence of DTBP on the thermal degradation mechanism of PAMS film.The effects of DTBP on PAMS film thermal degradation temperature,thermal degradation rate,molecular weight distribution and molecular weight are studied by using thermogravimetric analyzer,vacuum thermal decomposition furnace and small angle laser-gel penetration chromatography spectrometer(GPC),respectively.The results show that at low temperature the free radicals created by the DTBP will attack the PAMS backbone,leading to the decrease of the thermal degradation temperature of PAMS film and the degradation of initial molecular weight rapidly,and the increase of the thermal degradation rate of PAMS film at the early stage of degradation.(2)In this paper,the effects of DTBP on the properties and thermal degradation of PAMS were investigated.Based on the emulsion encapsulation technology,the PAMS microspheres with different initiator were fabricated firstly.The effects of DTBP on the sphericity,thermal degradation temperature,the pyrolysis products of PAMS microspheres are investigated by using 3020,TGA spectrometer and the Py-GC/MS,respectively.The results show that with the increase of DTBP content of PAMS microspheres,the sphericity(OOR)increases significantly and the addition of DTBP will decrease the temperature of thermal degradation of PAMS microspheres.After curing,PAMS microspheres still have DTBP residues,and with the increase of DTBP content in the microspheres,the residues gradually increases.(3)To investigate the effects of the mixture with different molecular,solvent residue and the appearance of PAMS on the thermal degradation performance,the thermogravimetry analyzer and Py-GC/MS are used in this work.The results show that:(a)compared with the undoped large molecular weight of PAMS,the thermal degradation temperature of the doped PAMS with different molecular weight is higher,but lower than that of the low molecular weight of PAMS;(b)the initial thermal degradation temperature of PAMS films is lowest and the initial thermal degradation temperature of PAMS materials is the highest.But the initial thermal degradation temperature of PAMS microspheres is between them.In addition,the thermal degradation temperature of different forms of PAMS is the same at the end of degradation process;(c)with the increase of the drying time,the solvent residue decrease.At the same time,the initial thermal degradation temperature of the PAMS films increase gradually.When the solvent residue is reduced to a certain extent,the thermal degradation temperature of PAMS thin films have no change. |
