Polymer compositions and methods for shielding radioactivity
A urethane based polymer composition is provided that exhibits superior shielding properties during and after exposure to high level radiation. The composite is formed by mixing a liquid isocyanate monomer, preferably 4,4′-diisocyanate monomer with a liquid phenolic resin, preferably phenol formaldehyde resin, and a phosphate ester flame retardant. An optional pyridine catalyst may be added to shorten the cure time. The resulting composition cures at room temperature and can be utilized in several manners, including spraying or pouring the composition prior to curing over radioactive material to prevent leakage of radiation. The uncured composite can be sprayed on the walls of a room or container to prevent leakage of radiation and can also be used to contain radiation prior to demolition. The uncured composite can also be molded into bricks or panels for use in construction. In a preferred embodiment, the polymer composition further incorporates radioactive waste, namely depleted uranium oxide, and can be used in conjunction with specially designed containers for storing radioactive material. The resulting polymer/waste composition cures at room temperature and does not deteriorate or suffer structural damage when exposed to higher levels of gamma radiation, nor do the mechanical or chemical properties undergo any detectable change. The composition is resistant to biodegradation and combustion, and does not creep or shrink during thermal cycling.
1 . A polymer composition for radiation shielding comprising:
about 25 to 75% at least one isocyanate monomer;
about 20 to 70% at least one phenolic resin; and
about 3 to 10% at least one halogenated phosphate ester flame retardant compound, wherein the isocyanate monomer, phenolic resin, and the halogenated phosphate ester retardant compound of the composition are combined to form a homogeneous mixture prior to curing of the composition.
2 . The polymer composition of claim 1 wherein the isocyanate monomer is an aromatic isocyanate.
3 . The polymer composition of claim 1 wherein the phenolic resin is produced by the polycondensation of a phenol compound with formaldehyde.
4 . The polymer composition of claim 1 further comprising a catalyst.
5 . A polymer composition for radiation shielding comprising:
about 25 to 75% at least one aromatic isocyanate monomer;
about 20 to 70% at least one phenolic resin, the phenolic resin being produced by the polycondensation of a phenol compound with formaldehyde;
about 3 to 10% at least one halogenated phosphate ester flame retardant and about 0 to 1.0% at least one catalyst;
wherein the isocyanate monomer, phenolic resin, halogenated phosphate ester retardant compound and the catalyst of the composition are combined to form a homogeneous mixture prior to curing of the composition.
6 . The polymer composition of claim 5 wherein the aromatic isocyanate monomer is diphenylmethane 4,4′-diisocyanate.
7 . The polymer composition of claim 5 wherein the phenolic resin is produced by the polycondensation of phenol with formaldehyde.
8 . The polymer composition of claim 5 wherein the catalyst is phenylpropyl pyridine.
9 . The polymer composition of claim 5 wherein the halogenated phosphate ester retardant is Firemaster 836™.
10 . The polymer composition of claim 1 wherein the homogeneous mixture is formed into a desired shape before allowing the homogeneous mixture to cure.
11 . The polymer composition of claim 1 wherein the homogeneous mixture is sprayed onto a surface to form a shield before allowing the homogeneous mixture to cure.
12 . A polymer composition for radiation shielding comprising:
about 40% diphenylmethane 4,4′-diisocyanate;
about 54% phenolic resin, the phenolic resin being produced by the polycondensation of phenol with formaldehyde; and
about 6% halogenated phosphate ester retardant;
wherein the diphenylmethane 4,4′-diisocyanate, phenolic resin and halogenated phosphate ester of the composition are combined to form a homogeneous mixture prior to curing of the composition.
13 . A polymer composition for radiation shielding comprising:
about 40% diphenylmethane 4,4′-diisocyanate;
about 53.85% phenolic resin, the phenolic resin being produced by the polycondensation of phenol with formaldehyde;
about 6% halogenated phosphate ester; and
about 0.15% phenylpropyl pyridine;
wherein the diphenylmethane 4,4′-diisocyanate, phenolic resin, halogenated phosphate ester and phenypropyl pyridine of the composition are combined to form a homogeneous mixture prior to curing of the composition.
14 . The process of making a polymer composition comprising:
mixing about 25-75% at least one isocyanate monomer;
about 20-70% phenolic resin; and
about 3 to 10% halogenated phosphate ester retardant compound, until a homogeneous mixture is formed; and
allowing the homogeneous mixture to cure.
15 . The process of making a polymer composition comprising:
mixing about 25-75% at least one isocyanate monomer;
about 20-70% phenolic resin; and
about 3 to 10% halogenated phosphate ester retardant compound, until a homogeneous mixture is formed;
forming the homogeneous mixture into a desired shape; and
allowing the homogeneous mixture to cure.
16 . The process of making a polymer composition comprising:
mixing about 40% diphenylmethane 4,4′-diisocyanate;
about 54% phenolic resin, the phenolic resin being produced by the polycondensation of phenol with formaldehyde; and
about 6% halogenated phosphate ester; and
allowing the homogeneous mixture to cure.
17 . The process of making a polymer composition comprising:
mixing about 40% diphenylmethane 4,4′-diisocyanate;
about 53.85% phenolic resin, the phenolic resin being produced by the polycondensation of phenol with formaldehyde;
about 6% halogenated phosphate ester; and
about 0.15% phenylproply pyridine until a homogeneous mixture is formed; and
allowing the homogeneous mixture to cure.
18 . A method for shielding a surface from radiation comprising:
preparing a radiation shielding polymer solution;
applying the polymer solution to the surface to be shielded; and
allowing the polymer solution that has been applied on the surface to cure.
19 . The method of claim 18 wherein the polymer solution is applied by a spraying means.
20 . The method of claim 18 wherein the polymer solution is prepared by:
mixing about 25 to 75% at least one isocyanate monomer;
about 20 to 70% phenolic resin;
about 3 to 10% halogenated phosphate ester retardant compound; and
about 0 to 1.0% catalyst, until a homogeneous mixture is formed.
21 . The method of claim 18 wherein the polymer solution is prepared by:
mixing about 25 to 75% at least one aromatic isocyanate monomer;
about 20-70% at least one phenolic resin, the phenolic resin being produced by the polycondensation of a phenol with formaldehyde;
about 3 to 10% at least one halogenated phosphate ester retardant compound; and
about 0 to 1.0% at least one catalyst, until a homogeneous mixture is formed.
22 . The method of claim 18 wherein the polymer solution is prepared by:
mixing about 40% diphenylmethane 4,4′-diisocyanate;
about 53.85 to 54% phenolic resin, the phenolic resin being produced by the polycondensation of phenol with formaldehyde;
about 6% halogenated phosphate ester; and
about 0-0.15 pyridine catalyst, until a homogeneous mixture is formed.
23 . The method of claim 18 wherein the polymer solution is prepared by:
mixing about 1.2 to 15% at least one isocyanate monomer;
about 1.0 to 14% phenolic resin;
about 0.2 to 1.0% halogenated phosphate ester retardant compound;
about 80 to 96% depleted uranium; and
about 0 to 1.0% catalyst, until a homogeneous mixture is formed.
24 . The method of claim 18 wherein the polymer solution is prepared by:
mixing about 1.2 to 15% diphenylmethane 4,4′-diisocyanate;
about 1.0 to 14% phenolic resin, the phenolic resin being produced by the polycondensation of phenol with formaldehyde; and
about 0.2 to 1.0% halogenated phosphate ester;
about 80-96% depleted uranium selected from the group consisting of UO 3 , UO 2 , U 3 O 8 and mixtures thereof; and
about 0 to 0.15% pyridine catalyst, until a homogeneous mixture is formed.
25 . The method of claim 18 wherein the polymer solution is prepared by:
mixing about 2.4% diphenylmethane 4,4′-diisocyanate;
about 3.6% phenolic resin, the phenolic resin being produced by the polycondensation of phenol with formaldehyde;
about 0.6% halogenated phosphate ester;
about 93.25 to 93.4% depleted uranium selected from the group consisting of UO 3 , UO 2 , U 3 O 8 and mixtures thereof; and
about 0 to 0.15% phenylproply pyridine, until a homogeneous mixture is formed.
26 . A method for containing radiation within a room, the room having structural components which make up the room, the structural components having interior surfaces, the method comprising:
preparing a radiation shielding polymer solution;
spraying the polymer solution on the interior surfaces of the structural components of the room; and
allowing the sprayed polymer solution to cure to a polymer film.
27 . The method of claim 26 wherein the polymer solution is prepared by:
mixing about 25 to 75% at least one isocyanate monomer;
about 20 to 70% phenolic resin;
about 3 to 10% halogenated phosphate ester retardant compound; and
about 0 to 1.0% catalyst, until a homogeneous mixture is formed.
28 . The method of claim 26 wherein the polymer solution is prepared by:
mixing about 25 to 75% at least one aromatic isocyanate monomer;
about 20-70% at least one phenolic resin, the phenolic resin being produced by the polycondensation of a phenol with formaldehyde;
about 3 to 10% at least one halogenated phosphate ester retardant compound; and
about 0 to 1.0% at least one catalyst, until a homogeneous mixture is formed.
29 . The method of claim 26 wherein the polymer solution is prepared by:
mixing about 40% diphenylmethane 4,4′-diisocyanate;
about 53.85 to 54% phenolic resin, the phenolic resin being produced by the polycondensation of phenol with formaldehyde;
about 6% halogenated phosphate ester; and
about 0-0.15 pyridine catalyst, until a homogeneous mixture is formed.
30 . The method of claim 26 wherein the polymer solution is prepared by:
mixing about 1.2 to 15% at least one isocyanate monomer;
about 1.0 to 14% phenolic resin;
about 0.2 to 1.0% halogenated phosphate ester retardant compound;
about 80 to 96% depleted uranium; and
about 0 to 1.0% catalyst, until a homogeneous mixture is formed.
31 . The method of claim 26 wherein the polymer solution is prepared by:
mixing about 1.2 to 15% diphenylmethane 4,4′-diisocyanate;
about 1.0 to 14% phenolic resin, the phenolic resin being produced by the polycondensation of phenol with formaldehyde; and
about 0.2 to 1.0% halogenated phosphate ester;
about 80-96% depleted uranium selected from the group consisting of UO 3 , UO 2 , U 3 O 8 and mixtures thereof; and
about 0 to 0.15% pyridine catalyst, until a homogeneous mixture is formed.
32 . The method of claim 26 wherein the polymer solution is prepared by:
mixing about 2.4% diphenylmethane 4,4′-diisocyanate;
about 3.6% phenolic resin, the phenolic resin being produced by the polycondensation of phenol with formaldehyde;
about 0.6% halogenated phosphate ester;
about 93.25 to 93.4% depleted uranium selected from the group consisting of UO 3 , UO 2 , U 3 O 8 and mixtures thereof; and
about 0 to 0.15% phenylproply pyridine, until a homogeneous mixture is formed.
33 . A method of containing radiation on radiation contaminated surfaces comprising:
preparing a radiation shielding polymer solution;
spraying the polymer solution on the contaminated surfaces; and
allowing the sprayed polymer solution to cure to a polymer film.
34 . The method of claim 33 wherein the polymer solution is prepared by:
mixing about 25 to 75% at least one isocyanate monomer;
about 20 to 70% phenolic resin;
about 3 to 10% halogenated phosphate ester retardant compound; and
about 0 to 1.0% catalyst, until a homogeneous mixture is formed.
35 . The method of claim 33 wherein the polymer solution is prepared by:
mixing about 25 to 75% at least one aromatic isocyanate monomer;
about 20-70% at least one phenolic resin, the phenolic resin being produced by the polycondensation of a phenol with formaldehyde;
about 3 to 10% at least one halogenated phosphate ester retardant compound; and
about 0 to 1.0% at least one catalyst, until a homogeneous mixture is formed.
36 . The method of claim 33 wherein the polymer solution is prepared by:
mixing about 40% diphenylmethane 4,4′-diisocyanate;
about 53.85 to 54% phenolic resin, the phenolic resin being produced by the polycondensation of phenol with formaldehyde;
about 6% halogenated phosphate ester; and
about 0-0.15 pyridine catalyst, until a homogeneous mixture is formed.
37 . The method of claim 33 wherein the polymer solution is prepared by:
mixing about 1.2 to 15% at least one isocyanate monomer;
about 1.0 to 14% phenolic resin;
about 0.2 to 1.0% halogenated phosphate ester retardant compound;
about 80 to 96% depleted uranium; and
about 0 to 1.0% catalyst, until a homogeneous mixture is formed.
38 . The method of claim 33 wherein the polymer solution is prepared by:
mixing about 1.2 to 15% diphenylmethane 4,4′-diisocyanate;
about 1.0 to 14% phenolic resin, the phenolic resin being produced by the polycondensation of phenol with formaldehyde; and
about 0.2 to 1.0% halogenated phosphate ester;
about 80-96% depleted uranium selected from the group consisting of UO 3 , UO 2 , U 3 O 8 and mixtures thereof; and
about 0 to 0.15% pyridine catalyst; until a homogeneous mixture is formed.
39 . The method of claim 33 wherein the polymer solution is prepared by:
mixing about 2.4% diphenylmethane 4,4′-diisocyanate;
about 3.6% phenolic resin, the phenolic resin being produced by the polycondensation of phenol with formaldehyde;
about 0.6% halogenated phosphate ester;
about 93.25 to 93.4% depleted uranium selected from the group consisting of UO 3 , UO 2 , U 3 O 8 and mixtures thereof; and
about 0 to 0.15% phenylproply pyridine, until a homogeneous mixture is formed.
40 . A method of molding radiation shielding objects comprising:
preparing an uncured radiation shielding polymer;
molding the uncured polymer solution into a desired object; and
allowing the polymer solution to cure to a solid.
41 . The method of claim 40 wherein the polymer solution is prepared by:
mixing about 25 to 75% at least one isocyanate monomer;
about 20 to 70% phenolic resin;
about 3 to 10% halogenated phosphate ester retardant compound; and
about 0 to 1.0% catalyst, until a homogeneous mixture is formed.
42 . The method of claim 40 wherein the polymer solution is prepared by:
mixing about 25 to 75% at least one aromatic isocyanate monomer;
about 20-70% at least one phenolic resin, the phenolic resin being produced by the polycondensation of a phenol with formaldehyde;
about 3 to 10% at least one halogenated phosphate ester retardant compound; and
about 0 to 1.0% at least one catalyst, until a homogeneous mixture is formed.
43 . The method of claim 40 wherein the polymer solution is prepared by:
mixing about 40% diphenylmethane 4,4′-diisocyanate;
about 53.85 to 54% phenolic resin, the phenolic resin being produced by the polycondensation of phenol with formaldehyde;
about 6% halogenated phosphate ester; and
about 0-0.15 pyridine catalyst, until a homogeneous mixture is formed.
44 . The method of claim 40 wherein the polymer solution is prepared by:
mixing about 1.2 to 15% at least one isocyanate monomer;
about 1.0 to 14% phenolic resin;
about 0.2 to 1.0% halogenated phosphate ester retardant compound;
about 80 to 96% depleted uranium; and
about 0 to 1.0% catalyst, until a homogeneous mixture is formed.
45 . The method of claim 40 wherein the polymer solution is prepared by:
mixing about 1.2 to 15% diphenylmethane 4,4′-diisocyanate;
about 1.0 to 14% phenolic resin, the phenolic resin being produced by the polycondensation of phenol with formaldehyde; and
about 0.2 to 1.0% halogenated phosphate ester;
about 80-96% depleted uranium selected from the group consisting of UO 3 , UO 2 , U 3 O 8 and mixtures thereof; and
about 0 to 0.15% pyridine catalyst, until a homogeneous mixture is formed.
46 . The method of claim 40 wherein the polymer solution is prepared by:
mixing about 2.4% diphenylmethane 4,4′-diisocyanate;
about 3.6% phenolic resin, the phenolic resin being produced by the polycondensation of phenol with formaldehyde;
about 0.6% halogenated phosphate ester;
about 93.25 to 93.4% depleted uranium selected from the group consisting of UO 3 , UO 2 , U 3 O 8 and mixtures thereof; and
about 0 to 0.15% phenylproply pyridine, until a homogeneous mixture is formed.
47 . The method of claim 40 wherein the method of molding is compression molding.