METHOD FOR RECYCLING POLYESTER/POLYURETHANE

Abstract

A method for recycling polyester/polyurethane is provided. The method comprises adding additives containing hydroxyl or/and amino groups to polyester/polyurethane waste and performing transesterification or transcarbamoylation at 80-180° C. to form recycled new materials with different structures including polyester, polyurethane, polyamide, and polyurea.

Claims

1. A method for recycling polyester/polyurethane, comprising: adding additives containing hydroxyl or/and amino groups to polyester/polyurethane waste; and performing transesterification or transcarbamoylation at 80-180° C. to form recycled new materials with different structures, including polyester, polyurethane, polyamide, and polyurea.

2. The method of claim 1, wherein the polyester/polyurethane waste is thermoset or thermoplastic polymer.

3. The method of claim 1, wherein an amount of the additives is 1 wt %-50 wt % of the polyester/polyurethane waste.

4. The method of claim 1, wherein the hydroxyl-containing additives are selected from one or more of hydroxyl-containing small molecules, hydroxyl-containing synthetic polymers, and hydroxyl-containing natural polymers.

5. The method of claim 4, wherein the hydroxyl-containing small-molecules include one or more of ethylene glycol, glycerin, butanediol, pentaerythritol, 3,5-dihydroxybenzyl alcohol, 3-amino-1,2-propanediol, and diethylene glycol; the hydroxyl-containing synthetic polymers include one or more of polyvinyl alcohol, polytetrahydrofurandiol, polycaprolactonediol, polyethylene glycol, polypropylene glycol, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polylactic acid, and polybutylene succinate; and the hydroxyl-containing natural polymers include one or more of starch, cellulose, glycogen, pentose, galactose, chitosan, chitin, and alginic acid.

6. The method of claim 1, wherein the amino group-containing additives are selected from one or more of amino-containing small molecules and amino-containing polymers.

7. The method of claim 6, wherein the amino-containing small molecules include one or more of aniline, amylamine, furfurylamine, 3-butoxypropylamine, n-hexylamine, octaamine, p-phenylenediamine, ethylenediamine, 1,6-hexanediamine, hexamethylenediamine, p-aminobenzylamine, 1,3-cyclohexanedimethylamine, N,N-bis(2-(Aminoethyl)-1,2-ethylenediamine, 2,2′,2″-triaminotriethylamine, and N,N,N,N-tetrakis(3-aminopropyl)-1,4-butane; and the amino-containing polymers include one or more of polyaniline, branched polyethyleneimine, polyetheramine, and polyoxyethylenediamine.

8. The method of claim 1, the method further comprising: adding bond exchange catalysts to the polyester/polyurethane waste, wherein an amount of the bond exchange catalysts is 0.01 wt %-10 wt % of the polyester/polyurethane waste.

9. The method of claim 2, the method further comprising: adding bond exchange catalysts to the polyester/polyurethane waste, wherein an amount of the bond exchange catalysts is 0.01 wt %-10 wt % of the polyester/polyurethane waste.

10. The method of claim 3, the method further comprising: adding bond exchange catalysts to the polyester/polyurethane waste, wherein an amount of the bond exchange catalysts is 0.01 wt %-10 wt % of the polyester/polyurethane waste.

11. The method of claim 4, the method further comprising: adding bond exchange catalysts to the polyester/polyurethane waste, wherein an amount of the bond exchange catalysts is 0.01 wt %-10 wt % of the polyester/polyurethane waste.

12. The method of claim 5, the method further comprising: adding bond exchange catalysts to the polyester/polyurethane waste, wherein an amount of the bond exchange catalysts is 0.01 wt %-10 wt % of the polyester/polyurethane waste.

13. The method of claim 6, the method further comprising: adding bond exchange catalysts to the polyester/polyurethane waste, wherein an amount of the bond exchange catalysts is 0.01 wt %-10 wt % of the polyester/polyurethane waste.

14. The method of claim 7, the method further comprising: adding bond exchange catalysts to the polyester/polyurethane waste, wherein an amount of the bond exchange catalysts is 0.01 wt %-10 wt % of the polyester/polyurethane waste.

15. The method of claim 8, wherein the bond exchange catalysts include one or more of triethylamine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1,8-diazabicycloundec-7-ene, benzenesulfonic acid, (4-methylphenyl)diphenylsulfonium trifluoromethanesulfonic acid, tin salt, zinc salt, calcium salt, magnesium salt, and cobalt salt.

16. The method of claim 1, the method further comprising: adding additional additives to react with free hydroxyl or/and amino groups, wherein the additional additives include one or more of isocyanate, isothiocyanate, epoxy, acid anhydride, carboxylic acid, and aldehyde.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG. 1 is the DSC curve of the materials in Example 1 before and after reprocessing with hydroxyl groups.

[0030] FIG. 2 is the stress-strain curve of Example 2 before and after polyurethane reprocessing with amino groups.

DETAILED DESCRIPTION

[0031] The present invention will be further described in detail with the examples below. It should be noted that the examples described below are intended to help understand the details of this invention. And the method should not be limited to these examples.

[0032] In the following examples, DSC was used to measure the glass transition, melting transition, and crystallinity before and after recycling. DMA was used to characterize the thermodynamic properties of materials, and a universal material testing machine was used to measure the mechanical properties before and after recycling.

Example 1 (Using Hydroxyl-Containing Polymers to Recycle Polyurethane)

[0033] Raw Material:

[0034] a) Hexamethylene diisocyanate (HDI), J&K Scientific Co., Ltd.;

[0035] b) Polycaprolactone diol (PCL): Mw=2000, Sigma-Aldrich Co., Ltd.;

[0036] c) Glycerin, Tokyo Chemical Industry Co., Ltd.;

[0037] d) Dibutyltin dilaurate (DBTDL), J&K Scientific Co., Ltd.;

[0038] e) Polybutylene glycol (PPG), J&K Scientific Co., Ltd.;

[0039] Preparation of Polyurethane:

[0040] Samples were weighed according to the ratio of PCL, glycerin, and HDI is 1:0.2:1.3 (molar ratio, wherein the molar ratio of the total hydroxyl number of PCL and glycerol to the isocyanate group was 1:1). After stirring properly, 0.1 wt % of DBTDL was added, and the mixed solution was poured into a mold. The mixture was reacted at 70° C. for 3 h.

[0041] Polyurethane Recycling:

[0042] 10 g of polyurethane was weighed and ground into powder in a ball mill machine. Subsequently, 1 g of PPG was added to the polyurethane powder. After mixing properly, the mixture was conducted at 120° C. for 2 hours in a mold. Finally, a new polyurethane was formed. The melting temperature of the recycled sample is 3° C., which higher than the original sample, as shown in FIG. 1.

Example 2 (Using Amino-Containing Polymers to Recycle Polyurethane)

[0043] Raw Material:

[0044] a) Diphenylmethane diisocyanate (MDI), J&K Scientific Co., Ltd.;

[0045] b) Polytetrahydrofurandiol (PTMG): Mw=1000, Sigma-Aldrich China;

[0046] c) Glycerin, Tokyo Chemical Industry Co., Ltd.; l

[0047] d) Polyetheramine (D230), J&K Scientific Co., Ltd.;

[0048] Preparation of Polyurethane:

[0049] The samples were weighed according to the ratio of PTMG, glycerin, and MDI of 1:0.2:1.3 (molar ratio, wherein the molar ratio of the total hydroxyl groups of PPG and glycerol to the isocyanate group was 1:1). After stirring properly, the mixed solution was poured into a mold and reacted for 3 hours under heating at 70° C.

[0050] Polyurethane Recycling:

[0051] 10 g of polyurethane was weighed and ground into powder in a ball mill machine. Subsequently, 1 g of D230 was added to the polyurethane powder and mixed properly. The mixture was conducted at 120° C. for 2 hours in a mold. Finally, a new polyurethane-polyurea was formed. The modulus of the recycled sample is 0.8 MPa, which is higher than the original sample. And the strain at break is 100% higher than the original sample, as shown in FIG. 2.

Example 3 (Adding Additives Twice to Recycle Polyurethane)

[0052] Raw Material:

[0053] a) Diphenylmethane diisocyanate (MDI), J&K Scientific Co., Ltd.;

[0054] b) Polytetrahydrofurandiol (PTMG): Mw=1000, Sigma-Aldrich Co., Ltd.;

[0055] c) Glycerin, Tokyo Chemical Industry Co., Ltd.;

[0056] d) Polyetheramine (D230), J&K Scientific Co., Ltd.;

[0057] Preparation of Polyurethane:

[0058] The samples were weighed according to the ratio of PTMG, glycerin, and MDI of 1:0.2:1.3 (molar ratio, wherein the molar ratio of the total hydroxyl groups of PPG and glycerol to the isocyanate group was 1:1). After stirring properly, the mixed solution was poured into a mold and reacted for 3 hours at 70° C.

[0059] Polyurethane Recycling:

[0060] 10 g of polyurethane was weighed and ground into powder in a ball mill machine. Then 1 g of D230 was added to the polyurethane powder and mixed well. After stirring evenly in a screw extruder at 120° C., 0.5 g of MDI was added. The mixture was molded at 120° C. for 2 h to obtain a new polyurethane-polyurea material. The modulus of the recovered sample is 1 MPa higher than the original sample, and the strength is 0.5 MPa higher than the original sample.

Example 4 (Recycling Polyester Using Small Molecules Containing Hydroxyl and Amino Groups)

[0061] Raw Material:

[0062] a) Dimethyl terephthalate, J&K Scientific Co., Ltd.;

[0063] b) 1,4-Butanediol, J&K Scientific Co., Ltd.;

[0064] c) Glycerin, Tokyo Chemical Industry Co., Ltd.;

[0065] d) N,N′-diisopropylcarbodiimide, J&K Scientific Co., Ltd.;

[0066] e) Pentaerythritol, J&K Scientific Co., Ltd.;

[0067] f) Aniline, J&K Scientific Co., Ltd.;

[0068] Preparation of Polyester:

[0069] The sample was weighted according to the molar ratio of dimethyl terephthalate, 1,4-butanediol and glycerol are 1.3:1:0.2 (molar ratio, wherein the molar ratio of the carboxyl groups of dimethyl terephthalate 1,4-butanediol, glycerol, and the total hydroxyl group of alcohol is 1:1). After stirring properly, 0.05 wt % of N,N′-diisopropylcarbodiimide was added, and the mixed solution was poured into a mold and reacted under vacuum at 120° C. for 8 hours.

[0070] Polyester Recycling:

[0071] 10 g of polyester was weighed and ground into powder in a ball mill machine. Subsequently, 0.5 g of pentaerythritol and aniline were added to the polyester powder. After mixing, the mixture was conducted at 120° C. for 5 hours in a mold. Finally, a new polyester material was obtained. The strain at break of the recycled sample is 5% higher than the original sample.

Example 5 (Recycling Polyester Using Hydroxyl/Amino-Containing Natural Polymer Filler)

[0072] Raw Material:

[0073] a) Dimethyl terephthalate, J&K Scientific Co., Ltd.;

[0074] b) 1,4-Butanediol, J&K Scientific Co., Ltd.;

[0075] c) Glycerin, Tokyo Chemical Industry Co., Ltd.;

[0076] d) N,N′-diisopropylcarbodiimide, J&K Scientific Co., Ltd.;

[0077] e) Hydroxyethyl cellulose, J&K Scientific Co., Ltd.;

[0078] Preparation of Polyester:

[0079] The sample was weighted according to the ratio of dimethyl terephthalate, 1,4-butanediol and glycerol are 1.3:1:0.2 (molar ratio, wherein the carboxyl group of dimethyl terephthalate, 1,4-butanediol, glycerol, and the hydroxyl group of alcohol is 1:1). After stirring properly, 0.05 wt % of N,N′-diisopropylcarbodiimide was added, and the mixed solution was poured into a mold and reacted under vacuum at 120° C. for 8 hours.

[0080] Polyester Recycling:

[0081] 10 g of polyester was weighed and ground into powder in a ball mill machine. Subsequently, 1 g of hydroxyethyl cellulose powder was added to the polyester powder. After mixing, the mixture was conducted at 120° C. for 3 hours in a mold. Finally, a new polyester was obtained. The modulus of the recovered sample is 10 MPa higher than the original sample, and the strength is 5 MPa higher than the original sample.

Example 6 (Recycling of Polyurethane Foam)

[0082] Raw Material:

[0083] a) Polyurethane foam insulation board, Shenzhen Lvjianbao Material Co., Ltd.;

[0084] b) Tripolyetheramine, J&K Scientific Co., Ltd.;

[0085] Recycling of Polyurethane Foam:

[0086] 10 g of polyurethane foam was weighed and ground into powder in a ball mill machine. Subsequently, 1 g of polyether amine was added to the polyurethane powder and conducted at 130° C. for 5 hours in a mold to obtain a new polyurethane film material. The strain at break of the recovered sample is 50% higher than the original sample.

Example 7 (Recycling of Polyester Fiber)

[0087] Raw Material:

[0088] a) Polyester fiber, Changzhou Zhuwei Building Material Co., Ltd.;

[0089] b) Polyetheramine (D230), J&K Scientific Co., Ltd.;

[0090] c) 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), Tokyo Chemical Industry Co., Ltd.;

[0091] Recycling of Polyester Fiber:

[0092] 10 g of polyester fiber was weighed and ground into powder in a ball mill machine. Subsequently, 1 g of D230 and 0.1 wt % of TBD were added to the polyurethane powder and conducted at 120° C. for 3 hours in a mold to obtain a new polyester film. The strain at break of the recycled sample is 10% higher than the original sample.

Example 8 (Recycling of Waste Buttons: Recycling of Ethylene and Styrene Copolymers)

[0093] Raw Material:

[0094] a) Buttons, Yongjia County Weizhi Button Co., Ltd.;

[0095] b) P-phenylenediamine, J&K Scientific Co., Ltd.;

[0096] c) 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), Tokyo Chemical Industry Co., Ltd

[0097] Recycling of Discarded Buttons:

[0098] 10 g of buttons were weighed and ground into powder in a ball mill machine. Subsequently, 1 g of p-phenylenediamine and 0.1 wt % of TBD were added to the polyurethane powder, mixed in a twin-screw extruder at 150° C. for 3 hours, and then conducted for 3 hours in a mold to obtain a new polyester film. The strain at break of the recycled sample is 20% higher than the original sample.