Process for degrading plastic products
The present invention relates to a process for degrading a plastic product comprising at least one polymer, the process comprising submitting the plastic product to a spinning step to obtain fibers of said plastic product; and depolymerizing at least one polymer of said fibers.
1 . A process for degrading a plastic product comprising at least one thermoplastic polymer, the process comprising:
a) submitting the plastic product to a spinning step to obtain fibers of said plastic product, wherein the spinning step comprises a melt-spinning step implemented with a plastic product in a partially or totally molten state, wherein the melt plastic product is extruded through spinnerets for non-woven products into fibers and wherein the fibers obtained exhibit a porosity rate above 30%; and
b) depolymerizing at least one thermoplastic polymer of said fibers by contacting said fibers with a biological depolymerizing agent.
2 . The process of claim 1 , wherein the melt-spinning step is performed at a temperature above the crystallization temperature (Tc) of at least one thermoplastic polymer of the plastic product.
3 . The process of claim 1 , wherein the fibers are cooled by submitting said fibers to a temperature below the crystallization temperature (Tc) of at least one target thermoplastic polymer of the plastic product.
4 . The process of claim 3 , wherein the target thermoplastic polymer in said fibers exhibits after cooling a crystallinity rate of at most 30%.
5 . The process of claim 1 , wherein the biological depolymerizing agent is a depolymerase.
6 . The process of claim 1 , wherein the biological depolymerizing agent is a depolymerase able to degrade at least one thermoplastic polymer of the plastic product.
7 . The process of claim 1 , further comprising a step of recovering and optionally purifying oligomers and/or monomers resulting from the depolymerization step.
8 . The process of claim 1 , wherein the at least one thermoplastic is a polyester selected from polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), polyethylene isosorbide terephthalate (PEIT), polylactic acid (PLA), polyhydroxy alkanoate (PHA), polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), polybutylene adipate terephthalate (PBAT), polyethylene furanoate (PEF), polycaprolactone (PCL), poly(ethylene adipate) (PEA), polybutylene succinate terephthalate (PBST), polyethylene succinate (PES), poly(butylene succinate/terephthalate/isophthalate)-co-(lactate) (PBSTIL) and blends/mixtures of these materials.
9 . A process for degrading a plastic product comprising at least PET comprising the steps of:
a) submitting said plastic product to melt-spinning at a temperature above 170° C., said melt-spinning being implemented with a plastic product in a partially or totally molten state, wherein the melt plastic product is extruded through spinnerets for non-woven products and wherein fibers obtained from said melt-spinning exhibit a porosity rate above 30%, and cooling the resulting fibers at a temperature below 100° C.;
b) depolymerizing PET in said fibers by contacting said fibers with a biological depolymerizing agent; and optionally
c) recovering and optionally purifying oligomers and/or monomers resulting from depolymerization of said PET.
10 . The process of claim 9 , wherein the depolymerizing step is performed by contacting the fibers with a depolymerase or a cutinase.
11 . A method of producing monomers and/or oligomers and/or degradation products from a plastic product comprising at least one thermoplastic polymer, comprising submitting successively the plastic product to a spinning step comprising a melt-spinning step implemented with the plastic product in a partially or totally molten state, wherein the melt plastic product is extruded through spinnerets for non-woven products and wherein extruded fibers obtained in said melt-spinning step exhibit a porosity rate above 30%, and to a depolymerizing step comprising exposing the plastic product to a depolymerase.
12 . A process for degrading a spun plastic product comprising at least one polymer, said process comprising a melt-spinning step implemented with a plastic product in a partially or totally molten state and extruding a melt plastic product through spinnerets for non-woven products and wherein extruded fibers obtained in said melt-spinning step exhibit a porosity rate above 30% and contacting the extruded fibers with a biological depolymerizing agent able to degrade at least one polymer of said plastic product, and wherein said spun plastic product is obtained from rigid or flexible plastic wastes and/or from crystalline plastic fibers.
13 . The process of claim 12 , wherein the biological depolymerizing agent is a depolymerase.
14 . The process of claim 12 , wherein said polymer of said plastic product has been previously amorphized before the depolymerisation step.
15 . A process for recycling a plastic product selected from rigid or flexible plastic wastes and/or from crystalline plastic fibers and comprising at least one target polymer, said process comprising comprising a melt-spinning step implemented with said plastic product in a partially or totally molten state and extruding a melt plastic product through spinnerets for non-woven products and wherein extruded fibers obtained in said melt-spinning step exhibit a porosity rate above 30% and contacting the extruded fibers with a biological depolymerizing agent, and wherein said at least one target polymer has been optionally amorphized.
16 . The process of claim 15 , wherein the process further comprises a step of recovering monomers and/or oligomers of said polymer.
17 . The process of claim 15 , wherein said biological depolymerizing agent is a depolymerase.