Outgassing Studies of Foams for the W80 LEP (FY05)

Alviso, C ; Harvey, C ; Vance, A

Lawrence Livermore National Laboratory

关键词: Removal;    Lawrence Livermore National Laboratory;    Polyurethanes;    Polymers;    37 Inorganic, Organic, Physical And Analytical Chemistry;   

DOI  :  10.2172/889995
RP-ID  :  UCRL-TR-217477
RP-ID  :  W-7405-ENG-48
RP-ID  :  889995

美国|英语

来源: UNT Digital Library

【 摘 要 】

Removable epoxy foam (REF) is a novel material developed by researchers at Sandia National Laboratories to simplify the removal of encapsulants from electronic components [McElhanon, et al., Journal of Applied Polymer Science, 2002, 85, 1496-1502]. The material is based on a resin that includes a thermally reversible chemical bond. When the material is heated at relatively mild temperatures ({approx}50-90 C) in the presence of appropriate solvents, the reversible bonds are broken, and the material is easily rinsed away. In order to ease the removal of the encapsulant for surveillance purposes, it was proposed to use REF in the W80 LEP in place of the polyurethane TDI (toluene diisocyanate), which is being phased out at the Kansas City Plant due to toxicity concerns. Colleagues at Sandia noted that REF exhibited especially high outgassing of the liquid fluorinert, FC-72, which is used at a level of 5 wt% as the blowing agent in the foaming process. After obtaining a sample of the material from Sandia, headspace solid phase microextraction gas chromatography-mass spectrometry (SPME GC/MS) measurements were performed. These measurements revealed significant outgassing of fluorinert as well as other solvents and siloxanes [Memo, Vance, 3/3/05 & Vance, Foam PRT presentation UCRL-PRES-212462]. This report is intended to summarize foam outgassing studies performed at LLNL in support of the W80 LEP.