Reduced density hollow glass microsphere polymer composite
The invention relates to a hollow glass microsphere and polymer composite having enhanced viscoelastic and rheological properties.
1. A shaped structural article formed by melt processing of a thermoplastic composite comprising a dispersion of a glass particulate and a fiber in a continuous thermoplastic polymer, the thermoplastic composite comprising:
(a) greater than 59 to 90 vol. % of a glass particulate having a particle size greater than about 5 microns,
(b) a fiber,
(c) about 0.005 to 8 wt. % of a coating of an interfacial modifier, the interfacial modifier free of a coupling agent, on the fiber and the glass particulate; and
(d) a continuous thermoplastic polymer, wherein the interfacial modifier coating on the glass particulate and the fiber allows for greater freedom of movement of the glass particulate within the continuous thermoplastic polymer of the thermoplastic composite, the percentages based on the thermoplastic composite wherein the continuous thermoplastic polymer is free of a polymer comprising tetrafluoroethylene, hexafluoropropylene or perfluoroalkylvinyl ether.
2. The shaped article of claim 1 wherein the thermoplastic composite density is about 0.2 to 5 gm-cm −3 .
3. The shaped article of claim 1 wherein the thermoplastic composite has a tensile strength of about 0.1 to 10 times that of the the continuous thermoplastic polymer.
4. The shaped article of claim 1 wherein the thermoplastic composite has a tensile elongation of about 5% to 100% of the the continuous thermoplastic polymer.
5. The shaped article of claim 1 wherein the thermoplastic composite has a tensile elongation of about 20% to 100% of the the continuous thermoplastic polymer.
6. The shaped article of claim 1 wherein the thermoplastic composite has a tensile strength of about 0.1 to 10 times that of the continuous thermoplastic polymer and a tensile elongation of about 15% to 90% of base the continuous thermoplastic polymer.
7. The shaped article of claim 1 wherein the thermoplastic composite has a thermoplastic shear at least about 5 sec −1 .
8. The shaped article of claim 1 wherein the glass particulate comprises microspheres having a particle size P S of about 10 to 1000 microns.
9. The shaped article of claim 1 wherein the thermoplastic composite additionally comprises a second particulate, wherein the second particulate comprises an inorganic material free of glass having a particle size (P s ) of about 2.5 to 1000 microns.
10. The shaped article of claim 9 wherein the second particulate has particle size P S 1 distribution ranging from about 10 to 500 microns.
11. The shaped article of claim 9 wherein the thermoplastic composite comprises greater than 5 vol-% of the second particulate having a particle size P S distribution ranging from about 2.5 to about 1000 microns.
12. The shaped article of claim 1 wherein the glass particulate has a particle size P S of about 10 to 200 microns and the thermoplastic composite additionally comprises a second particulate with a particle size P S 1 that differs from the glass particulate by at least 5 microns.
13. The shaped article of claim 12 wherein the second particulate has a particle size according to the formula P S ≧2 P S 1 or P S ≦0.5 P S 1 wherein P S is the particle size of the glass particulate and P S 1 is the particle size of the second particulate.
14. The shaped article of claim 13 wherein the circularity of the second particulate is 12.5 to 25.
15. The shaped article of claim 13 wherein the second particulate comprises a mixture of particles of differing composition.
16. The shaped article of claim 1 wherein the continuous thermoplastic polymer is selected from the group consisting of polyamide, poly (ethylene-co-vinyl acetate), synthetic rubber, polyolefin, high-density polyolefin, and polyvinyl chloride.