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 - 95 . (canceled)
96 . A melt processing method of manufacturing a hollow glass microsphere and polymer composite from a mixture, said method comprising:
(a) pre-treating a hollow glass microsphere with an effective composite forming amount of an interfacial modifier coating wherein the hollow glass microsphere has a particle size of at least about 5 microns;
(b) combining a thermoplastic polymer phase with about 30 to 95 volume % of a pre-treated interfacial modifier coated hollow glass microsphere, in an amount that can substantially occupy excluded volume of a hollow glass microsphere particle distribution in the composite; and
(c) melt process compounding the mixture to form the composite comprising the pre-treated hollow glass microspheres within the polymer phase;
wherein the hollow glass microsphere exhibits a circularity greater than 13 and an aspect ratio less than 1:3; and wherein the interfacial modifier coating allows for greater freedom of movement between the pre-treated hollow glass microsphere within the polymer phase compared to the same composite without the exterior coating on the hollow glass microsphere, when measured under the same conditions.
97 . The method according to claim 96 , wherein about 40 to 70 volume % of the hollow glass microsphere composite comprises the polymer phase.
98 . The method according to claim 96 , wherein the composite comprises about 0.02 to 3 wt.-% of the interfacial modifier.
99 . The method of claim 96 wherein the polymer phase has a density of about 0.86 gm-cm −3 .
100 . The method of claim 96 , wherein the composite has a density of about 0.4 to 5 gm-cm −3 .
101 . The method of claim 96 wherein the composite additionally comprises a solid particulate or a fiber, the particulate having a particle size (P s ) of about 5 to 1000 microns and the fiber having an aspect ratio of greater than 10.
102 . The method of claim 96 wherein after compounding, the method includes extruding the composite.
103 . The method of claim 97 wherein the polymer phase comprises a polyamide, poly (ethylene-co-vinyl acetate), a synthetic rubber, a polyvinyl chloride, a fluoropolymer, a polyolefin, a thermoset polymer.
104 . The method according to claim 96 , wherein said melt processing comprises injection molding the composite.
105 . The method according to claim 96 , wherein said melt processing comprises compression molding the composite.
106 . The composite formulation of claim 96 wherein the microsphere is a hollow glass microsphere.
107 . The composite formulation of claim 96 wherein the composite formulation has a tensile strength of about 0.1 to 10 times that of the polymer phase.
108 . The composite of claim 96 wherein the composite formulation has a tensile elongation of about 15% to 90% of the polymer phase.
109 . The composite of claim 96 wherein the composite formulation has a thermoplastic shear at least about 5 sec −1 .
110 . The composite formulation of claim 96 wherein the composite formulation has a tensile strength of at least 0.2 MPa and a thermoplastic shear of at least 5 sec −1
111 . The composite formulation of claim 96 wherein the hollow glass microsphere has a particle size P S of about 5 to 300 microns.