The invention relates to highly elastic polyurethane foams which are suitable as functional materials having thermally insulating properties.

A roofing membrane and a method of making the same is provided. The roofing membrane includes a top layer having a flame retardant and a first silane-crosslinked polyolefin elastomer with a density less than 0.90 g/cm.sup.3; a scrim layer; and a bottom layer having a flame retardant and a second silane-crosslinked polyolefin elastomer with a density less than 0.90 g/cm.sup.3. The top and bottom layers of the roofing membrane both exhibit a compression set of from about 5.0% to about 35.0%, as measured according to ASTM D 395 (22 hrs @ 70° C.).

A roofing membrane and a method of making the same is provided. The roofing membrane includes a top layer having a flame retardant and a first silane-crosslinked polyolefin elastomer with a density less than 0.90 g/cm.sup.3; a scrim layer; and a bottom layer having a flame retardant and a second silane-crosslinked polyolefin elastomer with a density less than 0.90 g/cm.sup.3. The top and bottom layers of the roofing membrane both exhibit a compression set of from about 5.0% to about 35.0%, as measured according to ASTM D 395 (22 hrs @ 70° C.).

A thermally expandable sheet includes: a first thermally expansive layer that is formed on one side of a base and contains a first thermally expandable material; and a second thermally expansive layer that is formed on the first thermally expansive layer and contains a second thermally expandable material, wherein the second thermally expandable material further contains white pigment.

A thermally expandable sheet includes: a first thermally expansive layer that is formed on one side of a base and contains a first thermally expandable material; and a second thermally expansive layer that is formed on the first thermally expansive layer and contains a second thermally expandable material, wherein the second thermally expandable material further contains white pigment.

Some embodiments are directed to a process for making a syntactic foam. Some other embodiments are directed to a process for manufacturing a buoyancy material including an outer shell and a syntactic foam. Still other embodiments are directed to the syntactic foam (or buoyancy foam) obtainable by this process. Some other embodiments are directed to a process of undersea extraction of oil including: using the syntactic. Still other embodiments are directed to an undersea extracting pipeline including a pipeline, and either the syntactic foam or the buoyancy material.

Some embodiments are directed to a process for making a syntactic foam. Some other embodiments are directed to a process for manufacturing a buoyancy material including an outer shell and a syntactic foam. Still other embodiments are directed to the syntactic foam (or buoyancy foam) obtainable by this process. Some other embodiments are directed to a process of undersea extraction of oil including: using the syntactic. Still other embodiments are directed to an undersea extracting pipeline including a pipeline, and either the syntactic foam or the buoyancy material.

A thermally expandable sheet includes: a first thermally expansive layer that is formed on one side of a base and contains a first thermally expandable material and a first binder, the first thermally expansive layer having a first ratio of the first thermally expandable material with respect to the first binder; and a second thermally expansive layer that is formed on the first thermally expansive layer and contains a second thermally expandable material and a second binder, the second thermally expansive layer having a second ratio of the second thermally expandable material with respect to the second binder, wherein the first ratio is lower than the second ratio.

Disclosed is a high filling and high resilience soft foaming polyethylene material, comprising the following parts of raw materials by weight: 15-20 parts polyethylene, 5-20 parts elastomers, 60-80 parts modified calcium carbonate, 1-10 parts chemical foaming agent, 0.5-1.5 parts crosslinking agent and 1-5 parts physical foaming agent. Also disclosed is a method of preparing high filling and high resilience soft foaming polyethylene material. The present invention can prepare a high calcium carbonate filling and high resilience soft foaming polyethylene material with calcium carbonate filler content as high as 55-75%, improving rigidity, hardness and compressive strength of the material while maintaining the elasticity of the foaming material, and reducing material density. The present invention has a simple process, greatly reduces costs and is economical and practical.

Disclosed is a high filling and high resilience soft foaming polyethylene material, comprising the following parts of raw materials by weight: 15-20 parts polyethylene, 5-20 parts elastomers, 60-80 parts modified calcium carbonate, 1-10 parts chemical foaming agent, 0.5-1.5 parts crosslinking agent and 1-5 parts physical foaming agent. Also disclosed is a method of preparing high filling and high resilience soft foaming polyethylene material. The present invention can prepare a high calcium carbonate filling and high resilience soft foaming polyethylene material with calcium carbonate filler content as high as 55-75%, improving rigidity, hardness and compressive strength of the material while maintaining the elasticity of the foaming material, and reducing material density. The present invention has a simple process, greatly reduces costs and is economical and practical.