Foamed plastic structures

Abstract

Foamed plastic structures that include one or more foamed plastic bodies containing a polymer matrix that includes one or more polymers formed by polymerizing a monomer mixture formed by polymerizing a monomer mixture containing vinyl aromatic monomers using a polymerization initiator having a structure corresponding to: R(Y) n where R is a C 2 to C 32 linear, branched, and/or cyclic aliphatic and/or aromatic group that can also include one or more atoms selected from oxygen, nitrogen, halides, silicon and sulfur, Y is a group that can generate a free radical capable of initiating polymerization of the monomers in the monomer mixture; and n is from 2 to 6. The structures formed can include, as non-limiting examples, pallets, containers, stackable containers, produce boxes, seafood shipping containers, geofoam blocks, and insulated concrete forms.

1 . A foamed plastic structure comprising one or more foamed plastic bodies comprising a polymer matrix that includes one or more polymers formed by polymerizing a monomer mixture that comprises vinyl aromatic monomers using a polymerization initiator having a structure corresponding to:
   R(Y) n      
     wherein R is a C 2  to C 32  linear, branched, and/or cyclic aliphatic and/or aromatic group that can also include one or more atoms selected from the group consisting of oxygen, nitrogen, halides, silicon and sulfur, Y is a group that can generate a free radical capable of initiating polymerization of the monomers in the monomer mixture; and n is from 2 to 6. 
   
   
       2 . The foamed plastic structure according to  claim 1 , wherein R is a neopentyl group and Y has a structure according to
   R 2 —O—O—C(O)—O—   
     wherein R 2  is selected from the group consisting of
 C 4-6  t-alkyl radicals. 
 
   
   
       3 . The foamed plastic structure according to  claim 1 , wherein R is polyalkylene glycol and Y has a structure according to
   —N≡N—.   
   
   
       4 . The foamed plastic structure according to  claim 1 , wherein R is a residue of a C 2  to C 32  linear polyhydroxy compound having 2 to 6 hydroxyl groups, Y has a structure according to 
     
       
         
         
             
             
         
       
     
     wherein R 1  is hydrogen, methyl or ethyl; n is from 1 to 6, A represents a group of formula —[O(CHR 2 CHR 3 ) a ]. y —, —[O(CH 2 ) b CO] y , or —O(CH 2 CO. (y-1) —[O(CHR 2 CHR 3 ) a ]— (where one of R 2  and R 3  is hydrogen and the other is hydrogen, methyl or ethyl); a is from 1 to 2; b is from 4 to 5; y is from 3 to 10. 
   
   
       5 . The foamed plastic structure according to  claim 1 , wherein the polymerization initiator has a structure according to 
     
       
         
         
             
             
         
       
     
     Wherein R 5  is hydrogen, methyl or ethyl and R 6  is hydrogen, methyl or ethyl. 
   
   
       6 . The foamed plastic structure according to  claim 1 , wherein R is a trimethyl cyclohexyl group and Y is a t-butylperoxy group. 
   
   
       7 . The foamed plastic structure according to  claim 1 , wherein the polymerization initiator is a copolymerizable organic peroxide initiator selected from the group consisting of acrylic acid derivatives containing a peroxide unit, alkylperoxy-alkylfumarates, and combinations thereof. 
   
   
       8 . The foamed plastic structure according to  claim 1 , wherein the polymerization initiator is a copolymerizable organic peroxide initiator selected from the group consisting of t-butylperoxy-isopropylfumarate, t-butylperoxy-n-butylfumarate, t-butylperoxy-sec-butylfumarate, t-butylperoxy-t-butylfumarate, t-butylperoxy-ethylfumarate, t-butylperoxy-n-hexylfumarate, t-butylperoxy-phenylfumarate, and combinations thereof. 
   
   
       9 . The structure according to  claim 1 , wherein Y includes an initiating group selected from the group consisting of peroxide groups, azo groups, percarbonate groups, perester groups, perketal groups, and combinations thereof. 
   
   
       10 . The foamed plastic structure according to  claim 1 , wherein the vinyl aromatic monomers are selected from the group consisting of styrene, isopropylstyrene, alpha-methylstyrene, nuclear methylstyrenes, chlorostyrene, tert-butylstyrene, vinyl toluene, vinyl xylene, ethyl vinyl benzene, vinyl naphthalene, para-methyl styrene, dibromostyrene and combinations thereof. 
   
   
       11 . The foamed plastic structure according to  claim 1 , wherein the monomer mixture includes a divinyl aromatic monomer selected from the group consisting of divinyl benzene, divinyl naphthalene, trivinyl benzene, divinyl toluene, divinyl xylene, divinyl alkyl benzenes, divinyl phenanthrene, divinyl biphenyl, divinyl diphenyl methane, divinyl benzyl, divinyl phenyl ether, divinyl diphenyl sulfide; divinyl furan; and combinations thereof. 
   
   
       12 . The foamed plastic structure according to  claim 8 , wherein the divinyl aromatic monomers are present in the monomer mixture at a level of from about 0.01 to about 0.07 wt. % of the monomer mixture. 
   
   
       13 . The foamed plastic structure according to  claim 1 , wherein the polymer matrix comprises polymers formed by polymerizing a monomer mixture that includes vinyl aromatic monomers using a multifunctional initiator and other thermoplastic polymers and/or elastomeric materials. 
   
   
       14 . The foamed plastic structure according to  claim 1  having a density of from about 0.5 lb/ft3 to about 12 lb/ft3. 
   
   
       15 . The foamed plastic structure according to  claim 1 , wherein the structure has a Flex Strength at 5% Strain, measured according to ASTM C 203-05, that is at least 5% higher than a similarly molded structure made from the same polymer composition with a mono-functional initiator. 
   
   
       16 . The foamed plastic structure according to  claim 1 , wherein the structure has a Compressive Strength at 10% Strain, measured according to ASTM D 1621-04a, that is at least 5% higher than a similarly molded structure made from the same polymer composition with a mono-functional initiator. 
   
   
       17 . The foamed plastic structure according to  claim 1 , wherein the structure is an insulated concrete form comprising a rectangular foamed plastic body that includes
 one or more beam forms defined by a first wall adjacent to and extending along a first side of the body, a second wall adjacent to and extending along a second side of the body, and a form bottom extending from a bottom edge of the first wall to a bottom edge of the second wall; and   one or more column forms extending generally parallel to the first side and the second side of the body and comprising a plurality of column walls extending from a top side of the body to a bottom side of the body.   
   
   
       18 . The foamed plastic structure according to  claim 1 , wherein the structure is an insulated concrete form comprising a first panel member, a second panel member, and one or more connecting members, wherein
 (A) the first panel member comprises at least one first slot in an inner side extending vertically therethrough;   (B) the second panel member comprises at least one second slot in an inner side extending vertically therethrough; and   (C) the connecting members comprise a first flange detachably and securably extending within said first slot of said first panel member, a second flange detachably and securably extending within said second slot of said second panel member; and a mid-section portion comprising a plurality of pour holes spaced along its length vertically.   
   
   
       19 . The foamed plastic structure according to  claim 1 , wherein the structure is a pallet comprising a base and a plurality of legs extending from one side of the base. 
   
   
       20 . The foamed plastic structure according to  claim 1 , wherein the structure is a container, comprising:
 the bottom part having a bottom wall, spaced generally parallel side walls and spaced generally parallel end walls, said side walls of said bottom part having vertical outer surfaces with tapered surfaces extending inwardly adjacent the lower portions thereof, said side walls of said bottom part having openings extending through the side walls of the bottom part and the tapered surfaces of the side walls of the bottom part, said tapered surfaces on the side walls of the bottom part having a height so that the openings in the bottom part extend solely through the tapered surfaces of the side walls of the bottom part,   the top part having a top having a top wall, spaced generally parallel side walls and spaced generally parallel end walls, said side walls of said top part having vertical outer surfaces with tapered surfaces extending inwardly adjacent the upper portions thereof, said side walls of said top part having openings extending through the side walls of the top part and the tapered surfaces of the side walls of the top part, said tapered surfaces on the side walls of the top part having a height so that the openings in the top part extend solely through the tapered surfaces of the side walls of the top part; and   cooperative mating means carried by the bottom and top parts whereby the top part is releasably secured to the bottom part to form an enclosed volume within the bottom and top parts which is ventilated by the openings in bottom and top parts.   
   
   
       21 . The foamed plastic structure according to  claim 1 , wherein the structure is a container comprising:
 a container portion having bottom and side walls, the upper periphery of the container side walls supporting an upwardly extending tongue therearound having a cross section with upwardly converging side surfaces; and   a closure portion having a lid panel that includes a flange therearound, the flange in cross section comprising two downwardly extending legs defining therebetween a tongue-receiving groove.   
   
   
       22 . The foamed plastic structure according to  claim 1 , wherein the structure is a stackable container comprising a bottom wall, four side walls extending upwardly from the peripheral edges of the bottom wall, and flanges extending along the upper edges of at least two opposite side walls and inwardly therefrom, wherein the flanges are adapted to receive a cover. 
   
   
       23 . The foamed plastic structure according to  claim 1 , wherein the structure is a transport box comprising side walls and end walls and a bottom, the side walls each having a vertical portion and an inwardly inclined upper portion, the top edge of the upper portion being horizontally turned outwardly forming a board-like support with its outer margin bent downwardly, a plurality of spaced vertical stiffening webs extending between the board-like support and the inclined upper portion, means forming tubular vertical reinforced corners at the junctures of the side and end walls, the tubular corners being closed at their tops, and a plurality of knobs on the upwardly facing surface of the board-like supports and ribs on the bottom of the box fitting between the knobs when the boxes are stacked. 
   
   
       24 . The foamed plastic structure according to  claim 1 , wherein the structure is a rectangular block. 
   
   
       25 . A method of reducing stresses on underlying soils or lateral pressures to retaining walls comprising:
 excavating a section of land:   placing one or more blocks according to  claim 24  over the excavated section of land; and   placing filling earth over at least a portion of the blocks.