Method for preparing 3D polymer objects with surface microstructures

Abstract

The present invention discloses a method for preparing stable 3D polymer objects with surface micro-nanostructures. The method includes the following steps: Step (1): Synthesizing a thermoset 2D polymer object with surface microstructures. The polymer network contains reversible exchangeable bonds. Step (2): deforming synthesized polymer to an arbitrary desired shape above the reshaping temperature with an external force applied. The permanent reshaping temperature falls in the range of 50-130 C. and external stress is held for 5 min-24 hours Step (3): after cooling, a permanent 3D polymer object with surface microstructure is obtained. Step (2-3) can be repeated for many cycles and the 2D polymer object can be arbitrarily and cumulatively deformed to get a complex 3D structures. The polymer networks contain reversible exchangeable bonds and bond exchange catalysts in the present invention. The method disclosed in present invention is simple and efficient for preparing complex 3D polymer objects with surface micro-nanostructures.

Claims

1. A method to prepare a 3D polymer with surface micro-nanostructures, comprising the following steps: step (1): synthesizing a 2D thermoset polymer with surface micro-nanostructures, wherein the polymer contains reversible exchangeable bonds; step (2): deforming the synthesized polymer to an arbitrary desired shape above the permanent reshaping temperature with an external force applied, wherein the reversible exchangeable bonds undertake reversible exchange; the reshaping temperature is above the glass transformation temperature or crystalline melting temperature of the polymer; above the reshaping temperature, the reversible exchangeable bonds are activated; step (3): after cooling, a permanent 3D polymer object with surface micro-nanostructure is obtained; wherein the polymer contains one or more of ester bond, urethane bond or urea bond while a bond exchange catalyst is added during synthesizing the polymer; and wherein steps (2)-(3) can be implemented multiple times to obtain an accumulated complex 3D sheet with surface micro-nanostructure.

2. The method of claim 1, wherein the reversible exchangeable bonds include one or more of ester bond, urethane bond, urea bond, siloxane bond, multiple hydrogen bond, and Diels-Alder reaction bond.

3. The method of claim 1, wherein the thermoset polymer is polyurethane resin, polyurethane-urea resin, acid/anhydride cured epoxy resin, resin with multiple hydrogen bond, or Diels-Alder reaction products.

4. The method of claim 1, wherein the bond exchange catalyst for ester bond, urethane bond, urea bond includes one or more of 1,5,7-triazabicyclo [4.4.0]dec-5-ene, benzyldimethylamide, and salts of tin, zinc, magnesium, cobalt, calcium, and benzyldimethylamide.

5. The method of claim 4, wherein the amount of the bond exchange catalyst ranges from 0.1-5% by weight of the polymer.

6. The method of claim 1, wherein, in step (2), the reshaping temperature is 10 C. above the glass transformation temperature or crystalline melting temperature of the polymer.

7. The method of claim 1, wherein the reshaping temperature falls in the range of 50-130 C. and external stress is held for 5 min-24 hours in step (2).

8. The method of claim 1, wherein the bond exchange catalyst for ester bond, urethane bond, urea bond includes one or more of 1,5,7-triazabicyclo [4.4.0]dec-5-ene, benzyldimethylamide, and salts of magnesium, cobalt, calcium.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 illustrates the 3D polymer with surface microstructures prepared by exemplary embodiment 1;

(2) FIG. 2 illustrates the 3D polymer with surface microstructures prepared by exemplary embodiment 2;

(3) FIG. 3 illustrates the 3D polymer with surface microstructures prepared by exemplary embodiment 3;

(4) FIG. 4 illustrates the 3D polymer s with surface microstructures prepared by exemplary embodiment 4.

DETAILED DESCRIPTION OF THE INVENTION

(5) Exemplary embodiments below are detailed descriptions of the present invention. However, the scope of protection is not restricted to exemplary embodiment below.

(6) Exemplary Embodiment 1 (Ester Bond-urethane Bond System)

(7) Raw Materials:

(8) a) Polycaprolactone diol (PCL diol): Mw=10,000, Sigma-Aldrich

(9) b) Poly(hexamethylene diisocyanate): Sigma-Aldrich

(10) c) Dibutyltin dilaurate (DBTDL): TCI

(11) d) 1,5,7-Triazabicyclo[4.4.0]dec-5-ene (TBD):TCI

(12) e) Dimethylformamide (DMF): Aladdin

(13) Preparation Method:

(14) 0.3 mmol polycaprolactone (PCL) diol and a stoichiometric amount of poly(hexamethylene diisocyanate) were added in 10 ml DMF and melted by heating in an oven at 80 C., wherein mass ratio of polycaprolactone and poly(hexamethylene diisocyanate) is the mole ratio of hydroxyl group and isocyanates group. A predetermined amount of DBTDL (0.5 wt % of total weight) and TBD (2 wt % of total weight) were dissolved into the mixture and stirred for several minutes. The mixture was poured into the mold with specific microstructures and curing was conducted thermally at 90 C. for 12 hours. After curing completely, the sample was demolded. Afterwards, the sample was bended into a 3D surface and thermally annealed under stress (130 C., 10 min), then cooled. Finally, a 3D surface with micro-nanostructures was obtained.

(15) Exemplary Embodiment 2 (Ester Bond-epoxy System)

(16) Raw Materials:

(17) a) Bisphenol A diglycidyl ethers: Mw=340, Aladdin

(18) b) Glutaric anhydride: Mw=114, Aladdin

(19) c) 1,5,7-Triazabicyclo[4.4.0]dec-5-ene (TBD): TCI

(20) d) Dimethylformamide (DMF): Aladdin

(21) Preparation Method:

(22) 1 mmol bisphenol A diglycidyl ethers and 1 mmol glutaric anhydride were added in 20 ml DMF and melted by heating in an oven at 100 C. A predetermined amount of TBD (2 wt % of total weight) were dissolved into the mixture and stirred for several minutes. The mixture was poured into the mold with specific microstructures and curing was conducted thermally at 110 C. for 12 hours. After curing completely, the sample was demolded. Afterwards, the sample was bended into a 3D surface and thermally annealed under stress (130 C., 10 min), then cooled. Finally, a 3D surface with micro-nanostructures was obtained.

(23) Exemplary Embodiment 3 (Urethane Bond System)

(24) Raw Materials:

(25) a) Poly(tetrahydrofuran) diol: Mw=2,000, Sigma-Aldrich

(26) b) Poly(hexamethylene diisocyanate): Sigma-Aldrich

(27) c) Dibutyltin dilaurate (DBTDL): TCI

(28) d) 1,5,7-Triazabicyclo[4.4.0]dec-5-ene (TBD):TCI

(29) e) Dimethylformamide (DMF): Aladdin

(30) Preparation Method:

(31) 0.2 mmol poly(tetrahydrofuran) diol, 0.2 mmol poly(hexamethylene diisocyanate) were added in 10 ml DMF and melted by heating in an oven at 80 C., wherein mass ratio of polycaprolactone and poly(hexamethylene diisocyanate) is the mole ratio of hydroxyl group and isocyanates group. A predetermined amount of DBTDL (0.5 wt % of total weight) and TBD (2 wt % of total weight) were dissolved into the mixture and stirred for several minutes. The mixture was poured into the mold with specific microstructures and curing was conducted thermally at 90 C. for 12 hours. After curing completely, the sample was demolded. Afterwards, the sample was bended into a 3D surface and thermally annealed under stress (130 C., 10 min), then cooled. Finally, a 3D surface with micro-nanostructures was obtained.

(32) Exemplary Embodiment 4 (Ester Bond-unsaturated Polyester System)

(33) Raw Materials:

(34) a) Orthophthalic unsaturated polyester oligomer: with 15 wt % maleic anhydride

(35) b) Styrene: Aladdin

(36) c) Cyclohexanone peroxide (UV-184): Aladdin

(37) d) Cobaltous naphthenate: Aladdin

(38) e) 1,5,7-Triazabicyclo[4.4.0]dec-5-ene (TBD): TCI

(39) Preparation Method:

(40) 6.5 g orthophthalic unsaturated polyester oligomer, 3.5 g styrene, 0.1 g UV-184, 0.05 g cobaltous naphthenate, and 0.2 g TBD were fully mixed at room temperature. The mixture was poured into the mold with specific microstructures and curing was conducted thermally at 60 C. for 4 hours. After curing completely, the sample was demolded. After curing completely, the sample was demolded. Afterwards, the sample was bended into a 3D surface and thermally annealed under stress (130 C., 10 min), then cooled. Then, a 3D surface with microstructures was obtained. The structures were reheated and bended into a 3D surface and thermally annealed under stress (130 C., 10 min), then cooled. Finally, a 3D surface with micro-nanostructures was obtained.

(41) Exemplary Embodiment 5 (Siloxane Bond System)

(42) Raw Materials:

(43) a) Dow Corning Sylgard Elastomer 184 (a base and a curing |agent|[1])

(44) b) Dibenzylamine: Sigma-Aldrich

(45) Preparation Method:

(46) Weight a certain amount of base and curing agent to the glass bottle (weight ratio: 10:1). A predetermined amount of dibenzylamine (0.5 wt % of total weight) were dissolved into the mixture and stirred for several minutes. The mixture was poured into the mold with specific microstructures and curing was conducted thermally at 100 C. for 1 h. After curing completely, the sample was demolded. Afterwards, the sample was bended into a 3D surface and thermally annealed under stress (110 C., 20 min). Finally, a 3D surface with microstructures was obtained.

(47) Exemplary Embodiment 6 (Multiple Hydrogen Bond System)

(48) Raw Materials:

(49) a) Poly(ethylene glycol) diacrylate (PEGDA): Aladdin

(50) b) Pentaerythritol tetrakis(3-mercaptopropionate) (PTME): Sigma-Aldrich

(51) c) 2-Isocyanatoethyl methacrylate (IEMA): J&K Scientific

(52) d) 2-Amino-4-hydroxy-6-methylpyrimidine (MIS): J&K Scientific

(53) e) Dimethylformamide (DMF): Aladdin

(54) f) Dimethylsulfoxide (DMSO): Sinopharm Chemical Reagent Co., Ltd.

(55) g) Triethylamine: Sinopharm Chemical Reagent Co., Ltd.

(56) Preparation Method:

(57) Preparation of UPyMA: 3 g MIS and 30 ml DMSO were weighted into a flask and melted by heating in an oven at 140 C. After the mixing, 3.72 g IEMA was added to the flask and the reaction proceeded for 10 min. Afterwards, the mixture was rapid cooled to the room temperature and white powders UPyMA precipitated out. After filtering, the powders were washed by alcohol. Finally, the UPyMA was oven dried at 80 C. overnight.

(58) Polymer synthesis: PTME, PEGDA, and UPyMA (mole ratio: 1:2.4:1.6) were added in DMF, followed by the addition of triethylamine (1 wt % of total monomer weight) as the catalyst. The total monomer concentration was maintained at 40 wt % (by monomer weight). The well stirred solution was injected to a mold and the reaction proceeded in an oven at 80 C. for 6 hours. The resulting sample was dried at 80 C. in vacuum. Afterwards, the sample was bended into a 3D surface and thermally annealed under stress (130 C., 10 min). Finally, a 3D surface with micro-nanostructures was obtained.

(59) Exemplary Embodiment 7 (Diels-Alder Reaction System)

(60) Raw Materials:

(61) a) Furfuryl amine (FA): TCI

(62) b) 2,2-Bis(4-glycidyloxyphenyl)propane (BGPP): TCI

(63) c) 1,1-(Methylenedi-4,1-phenylene)bismaleimide (BM): Sigma-Aldrich

(64) d) Dimethylformamide (DMF): Aladdin

(65) Preparation Method:

(66) 1.75 g BGPP and 0.5 g FA were added in 5.5 g DMF and curing was conducted thermally at 120 C. for 10 hours. Afterwards, the mixture was poured into a tetrafluoroethylene mold followed by the addition of 0.39 g BM. The postcuring was conducted thermally at 70 C. for 5 hours and vacuum oven dried for 48 hours. After curing completely, the sample was demolded. Afterwards, the sample was bended into a 3D surface and thermally annealed under stress (130 C., 10 min). Finally, a 3D surface with micro-nanostructures was obtained.