Polymer foams

Abstract

Monomodal foamed polymeric compositions containing clay nucleating agents are described. The clays are preferably sepiolite, palygorskite/attapulgite, or combinations thereof. Also described are processes for forming the foamed compositions.

1 . A concentrate composition used to form a monomodal polymer foam comprising:
 at least one carrier comprising at least one of i) a thermoplastic polymer and ii) a thermoset polymer; and   at least one sepiolite-type clay dispersed in the at least one carrier in an amount of from about 5% to about 70% by weight of the concentrate composition:   wherein when the at least one carrier comprises i) a thermoplastic polymer, then a blowing agent is used to form the polymer foam is substantially free of water.   
     
     
         2 . The concentrate composition according to  claim 1 , further comprising at least one additive agent dispersed in the polymeric matrix, wherein the additive agent is selected from the group consisting of flame retardants, secondary nucleating agents, blowing agents, dyes, pigments, lubricants, antistatic agents, biocides, aging modifiers, heat stabilizers, antioxidants, ultraviolet stabilizers, coupling agents, fillers, acid scavengers, preservatives, plasticizers, impact modifiers, chain extenders, graphite, graphene, hydrophilic agents, and combinations thereof. 
     
     
         3 . The concentrate composition according to  claim 2 , wherein the flame retardant additive is a halogenated compound, including polymeric halogenated additives. 
     
     
         4 . The concentrate composition according to  claim 3 , wherein the halogenated compound is selected from the group consisting of tris(tribromoneopentyl)phosphate, tetrabromobisphenol A bis (2,3-dibromopropyl ether), hexabromocyclododecane (HBCD), and mixtures thereof. 
     
     
         5 . The concentrate composition according to  claim 2 , wherein the flame retardant additive is a phosphorus compound and is selected from the group consisting of organophosphorus-sulfur compounds, phosphates, phosphites, phosphonates, phosphinates, phosphine oxides, phosphines, phosphonium salts, phosphorus-sulfur compounds, and combinations thereof. 
     
     
         6 . The concentrate composition according to  claim 2 , wherein the at least one additive agent includes a secondary nucleating agent selected from the group consisting of talc, wollastonite, zeolite, diatomaceous earth, a molecular sieve material, or combinations thereof. 
     
     
         7 . The concentrate composition according to  claim 1  wherein the sepiolite-type clay is attapulgite. 
     
     
         8 . The concentrate composition according to  claim 1  wherein the sepiolite-type clays are pre-wetted with water. 
     
     
         9 . The concentrate composition according to  claim 2  further comprising at least one blowing agent dispersed in the polymeric matrix. 
     
     
         10 . The concentrate composition according to  claim 2  wherein the additive agents includes alkyl sulfonate. 
     
     
         11 . The concentrate composition according to  claim 1 , wherein dispersing is performed by mixing the thermoplastic carrier and the sepiolite-type clays in an extruder.