Synthesis and characterization of new polyether based soluble polyurethanes
It was undertaken to develop a rmovable material which would have properties similar to crosslinked, insoluble encapsulants but allow rework capability. Applications require minimal creep at 80/sup 0/C, tensile yield strength of approx. 14 Mpa (2000 psi), glass-transition temperature of approx. -70/sup 0/C, percent elongation of approx. 400%, volume resistivity > 10/sup 10/ ohm-cm, and a shear modulus of 14-27 Mpa (2000-4000 psi) which does not decrease significantly in the temperature range 20-120/sup 0/C. A series of polyether-based soluble polyurethanes has been synthesized and a number of mechanical and electrical properties have been measured. The polyurethanes were forumulated using bitolylene diisocyanate (TODI), polytetramethylene ether glycol (several molecular weights were tried) and two different diols. A number of forumulations were tried and efforts concentrated on the two most promising materials. Since it was determined that the cure was not complete after the standard length of time (16 hours, verified by an isocyanate absorption in the infrared scan at 2280 cm/sup -1/), a post cure of sixteen hours was carried out. Average test results on the two best formulations were: (1) shear modulus 30-35 Mpa, (2) glass transition temperature -70/sup 0/C, (3) 400 percent elongation, (4) tensile strength 14 Mpa, (5) volume resistivity 10/sup 13/ ohm-cm, and (6) solubility in tetrahydrofuran. The post cure did not significantly improve any of the properties of the material.
- Research Organization:
- Sandia Labs., Albuquerque, NM (USA)
- DOE Contract Number:
- EY-76-C-04-0789
- OSTI ID:
- 6064839
- Report Number(s):
- SAND-78-1866C; CONF-790917-3
- Country of Publication:
- United States
- Language:
- English
Similar Records
A superplastic Al-Li-Cu-Mg-Zr powder alloy with high hardness and modulus
Characterization of a polyimide matrix for fiber composites
Related Subjects
360401* -- Polymers & Plastics-- Preparation & Fabrication-- (-1987)
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301 -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
CURING
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ESTERS
FURANS
HETEROCYCLIC COMPOUNDS
ISOCYANIC ACID ESTERS
MECHANICAL PROPERTIES
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANIC POLYMERS
PETROCHEMICALS
PETROLEUM PRODUCTS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
PLASTICS
POLYAMIDES
POLYMERS
POLYURETHANES
SHEAR PROPERTIES
SOLUBILITY
SYNTHESIS
TENSILE PROPERTIES