Degradable composite material and preparation method therefor and use thereof

Abstract

The present invention relates to the technical field of polymer material manufacturing, and in particular, disclosed are a degradable composite material and a preparation method therefor and a use thereof. The degradable composite material comprises polylactic acid, poly-3-hydroxybutyrate, and a flexible hydroxy fatty acid ester polymer.

Description

A degradable composite material and its preparation method and application Technical Field

[0001] The present invention relates to the field of polymer materials, and in particular to a degradable composite material and a preparation method and application thereof. Background Art

[0002] With the rapid development of the economy and the improvement of people's living standards, people have higher and higher requirements for environmental quality. However, the global use of non-degradable disposable plastics has exacerbated the white pollution of the human living environment. Common biodegradable materials at home and abroad, such as polylactic acid (PLA), polycaprolactone (PCL), polybutylene adipate / terephthalate (PBAT), polybutylene succinate (PBS), and polyhydroxyalkanoates (PHA), have developed well, their performance has been continuously improved, and their applications are becoming more and more extensive, such as in daily necessities, medical fields, packaging fields, and catering fields. However, because some biodegradable materials are petroleum-based, such as PBS and PBAT, they are not environmentally friendly during their life cycle. Bio-derived PLA has defects such as brittleness and easy breakage, easy deformation at high temperatures, uneven dyeing and difficulty in coloring during use, and therefore is subject to many restrictions in its use.

[0003] Therefore, it is necessary to develop low-cost composite materials with good toughness, good heat resistance and easy coloring and dyeing to broaden the scope of application of downstream products of the materials.

[0004] Summary of the Invention

[0005] The purpose of the present invention is to overcome the technical difficulties of the prior art, such as poor toughness, narrow operating temperature range, and difficulty in coloring and dyeing of PLA materials.

[0006] To achieve the above objectives, the biodegradable composite material of the present invention utilizes a method of blending polylactic acid with poly-3-hydroxybutyrate to increase the material's operating temperature range. The blending of a flexible hydroxy fatty acid ester polymer improves the material's toughness, coloring, and dyeing properties. Furthermore, by adding additives, the compatibility, thermal processability, molecular weight, toughness, operating temperature range, and coloring and dyeing properties of the biodegradable composite material are further enhanced. Experiments have confirmed that the biodegradable composite material of the present invention exhibits good toughness, a high thermal softening temperature, easy dyeing with good dyeing uniformity, excellent overall performance, stable thermal processing, and a wide processing window, making it well suited for downstream thermal processing and molding, broadening the application range of the product.

[0007] The first aspect of the present invention provides a degradable composite material, wherein the degradable composite material (or its raw material) comprises a substrate, wherein the substrate comprises: polylactic acid, and a hydroxy fatty acid ester polymer, wherein the hydroxy fatty acid ester polymer comprises poly-3-hydroxybutyrate and a flexible hydroxy fatty acid ester polymer.

[0008] Preferably, the elongation at break of the flexible hydroxy fatty acid ester polymer is greater than or equal to 20%, and the melt index is greater than or equal to 1 g / 10 min.

[0009] Preferably, the mass ratio of the poly-3-hydroxybutyrate and the flexible hydroxy fatty acid ester polymer is any value in (0.2-7):1, more preferably (0.5-4):1, and more preferably any value in (1-2):1, for example, (0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.25, 1.3, 1.4, 1.5, 1.6, 1.62, 1.66, 1.67, 1.7, 1.73, 1.8, 1.9, 2, 2.42, 2.43, 3, 4, 5, 6, 7):1.

[0010] The above melt index is obtained by referring to the test method of GB / T 3682-2000, and is measured under the test conditions of 190°C and 2.16 kg. The following are similar.

[0011] Preferably, the elongation at break of the flexible hydroxy fatty acid ester polymer is any value between 20% and 800%, more preferably any value between 20% and 300%, for example, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, 200%, 300%, 400%, 500%, 600%, 700% or 800%.

[0012] Preferably, the melt index of the flexible hydroxy fatty acid ester polymer is any value in the range of 1 g / 10min-30 g / 10min, more preferably any value in the range of 1 g / 10min-15 g / 10min, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25 or 30 g / 10min.

[0013] Preferably, the polymer includes a homopolymer, a copolymer (such as an alternating copolymer, a random copolymer, a block copolymer)

[0014] Preferably, the flexible hydroxy fatty acid ester polymer comprises monomers, dimers or polymers constituting flexible hydroxy fatty acid esters.

[0015] More preferably, the monomers constituting the flexible hydroxy fatty acid ester polymer include, but are not limited to, one or more of 2-hydroxypropionic acid, 3-hydroxypropionic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 3-hydroxypentanoic acid, 5-hydroxypentanoic acid, 3-hydroxyhexanoic acid, 3-hydroxyheptanoic acid, 6-hydroxyhexanoic acid, 3-hydroxyoctanoic acid, 3-hydroxynonanoic acid, 3-hydroxydecanoic acid, 3-hydroxyundecanoic acid or 3-hydroxydodecanoic acid.

[0016] Preferably, the flexible hydroxy fatty acid ester polymer includes but is not limited to one or more of P3HP, P(HA-LA), PHV, P34HB, PHBV, PHBHHx, PHBHHp, PHO, PHN, PHD, P3HB4HB3HV or P3HB4HB5HV.

[0017] Among them, the HA in P(HA-LA) includes one or more of 3-hydroxybutyric acid, 4-hydroxybutyric acid, 3-hydroxyvaleric acid, 5-hydroxyvaleric acid, 3-hydroxyhexanoic acid, 3-hydroxyheptanoic acid, 6-hydroxyhexanoic acid, 3-hydroxyoctanoic acid, 3-hydroxynonanoic acid, 3-hydroxydecanoic acid, 3-hydroxyundecanoic acid or 3-hydroxydodecanoic acid.

[0018] Preferably, in the substrate, the mass ratio of polylactic acid to hydroxy fatty acid ester polymer is (1-3):1, more preferably (1-2):1, more preferably (1-1.5):1, for example, 1:1, 1.13:1, 1.14:1, 1.15:1, 1.2:1, 1.25:1, 1.3:1, 1.34:1, 1.35:1, 1.40:1, 1.41:1, 1.5:1, 1.67:1, 2:1, 2.5:1, and 3:1.

[0019] In a specific embodiment of the present invention, the mass ratio of polylactic acid to hydroxy fatty acid ester polymer is 5:3, 3:1, 7:5, 55:41, 51.5:44.6, 51.1:45, and 56.1:40.

[0020] Preferably, in the degradable composite material (or its raw material), the mass of polylactic acid is any value between 20% and 80% (preferably 40% to 75%, further preferably 50% to 72%) of the total mass of the degradable composite material (or its raw material), for example, 20%, 30%, 35%, 40%, 45%, 50%, 51%, 51.1%, 51.5%, 55%, 56%, 56.1%, 60%, 65%, 70%, 72%, 75%, and 80%.

[0021] Preferably, in the degradable composite material (or its raw material), the mass of poly-3-hydroxybutyrate is any value between 5% and 50% (preferably between 5% and 40%, more preferably between 5% and 35%) of the total mass of the degradable composite material (or its raw material), for example, 5%, 6%, 10%, 15%, 17%, 20%, 25%, 26%, 27.6%, 30%, 35%, 40%, 45%, and 50%.

[0022] Preferably, in the degradable composite material (or its raw material), the mass of the flexible hydroxy fatty acid ester polymer is any value between 5% and 50% (preferably between 5% and 40%, more preferably between 5% and 30%) of the total mass of the degradable composite material (or its raw material), for example, 5%, 7%, 10%, 15%, 17%, 20%, 25%, 26%, 30%, 35%, 40%, 45%, or 50%.

[0023] Preferably, the monomer of the flexible hydroxy fatty acid ester polymer may include 3HB or not.

[0024] When the monomer of the flexible hydroxy fatty acid ester polymer includes 3HB, the molar content of the non-3HB monomer in the flexible hydroxy fatty acid ester polymer is any value in the range of 1-50%, more preferably any value in the range of 5-50%, for example, any value in the range of 10-30%, for example, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%.

[0025] In a specific embodiment of the present invention, the flexible hydroxy fatty acid ester polymer is P34HB, and the molar content of 4HB in the P34HB is any value between 1% and 50%, for example, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, and 50%. Preferably, the molar content of 4HB in the P34HB is 15% or 20%.

[0026] In a specific embodiment of the present invention, the flexible hydroxy fatty acid ester polymer is PHBV, and the molar content of 3HV in the PHBV is any value between 1% and 50%, for example, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, and 50%. Preferably, the molar content of 3HV in the PHV is 15%.

[0027] In a specific embodiment of the present invention, the flexible hydroxy fatty acid ester polymer is PHBHHx. Preferably, the molar content of 3HHx in the PHBHHx is any value between 1% and 50%, for example, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%. Preferably, the molar content of 3HHx in the PHBHHx is 20%.

[0028] In a specific embodiment of the present invention, the flexible hydroxy fatty acid ester polymer in the degradable composite material (or its raw material) is P34HB. Preferably, the mass ratio of poly-3-hydroxybutyrate to P34HB is 26:15 or 27.6:17.

[0029] In a specific embodiment of the present invention, the flexible hydroxy fatty acid ester polymer in the degradable composite material (or its raw material) is PHBV. Preferably, the mass ratio of poly-3-hydroxybutyrate to PHBV is 5:4.

[0030] In a specific embodiment of the present invention, the flexible hydroxy fatty acid ester polymer in the degradable composite material (or its raw material) is PHBHHx. Preferably, the mass ratio of poly-3-hydroxybutyrate to PHBHHx is 5:3.

[0031] Preferably, the polylactic acid and hydroxy fatty acid ester polymers can be prepared by chemical synthesis, biological fermentation or purchased.

[0032] Preferably, the molecular weight of the polylactic acid is any value between 50,000 and 500,000, more preferably any value between 100,000 and 300,000, more preferably any value between 120,000 and 180,000, for example, 50,000, 100,000, 110,000, 120,000, 130,000, 140,000, 150,000, 160,000, 170,000, 180,000, 190,000, 200,000, 250,000, 300,000, 350,000, 400,000, 450,000 or 500,000.

[0033] Preferably, the molecular weight of the poly-3-hydroxybutyrate is any value greater than 150,000, more preferably any value between 150,000 and 5,000,000, more preferably any value between 300,000 and 1,000,000, for example, 150,000, 200,000, 250,000, 300,000, 350,000, 400,000, 450,000, 500,000, 550,000, 600,000, 650,000, 700,000, 750,000, 800,000, 850,000, 900,000, 950,000, 1,000,000, 1,500,000, 2,000,000, 2,500,000, 3,000,000, 3,500,000, 4,000,000, or 5,000,000.

[0034] Preferably, the molecular weight of the flexible hydroxy fatty acid ester polymer is any value above 150,000, more preferably any value between 150,000 and 5,000,000, more preferably any value between 300,000 and 1,000,000, for example, 150,000, 200,000, 250,000, 300,000, 350,000, 400,000, 450,000, 500,000, 550,000, 600,000, 650,000, 700,000, 750,000, 800,000, 850,000, 900,000, 950,000, 1,000,000, 1,500,000, 2,000,000, 2,500,000, 3,000,000, 3,500,000, 4,000,000, 4,500,000 or 5,000,000.

[0035] Preferably, the degradable composite material (or its raw material) further comprises an auxiliary agent.

[0036] Preferably, the added mass of the additive accounts for any value between 0% and 5% of the total mass of the degradable composite material (or its raw material), and more preferably any value between 0.5% and 4%, for example, 0%, 0.00001%, 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 4%, 4.5%, and 5%.

[0037] Preferably, the auxiliary agent includes but is not limited to one or more of an initiator, a cross-linking agent, a chain extender, an anti-hydrolysis agent, an antioxidant or a thermal stabilizer.

[0038] In a specific embodiment of the present invention, the auxiliary agent includes an initiator and a cross-linking agent.

[0039] In a specific embodiment of the present invention, the auxiliary agent includes a chain extender, an anti-hydrolysis agent and a heat stabilizer.

[0040] In a specific embodiment of the present invention, the auxiliary agents include an initiator, a cross-linking agent, a chain extender, an anti-hydrolysis agent, an antioxidant and a heat stabilizer.

[0041] Preferably, the added mass of the initiator is any value between 0% and 5% of the total mass of the degradable composite material (or its raw material), preferably any value between 0.01% and 0.5%, for example, 0.00001%, 0.01%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.4%, 0.5%, 1%, 2%, 3%, 4%, and 5%.

[0042] Preferably, the initiator comprises a peroxide, and further preferably, the peroxide comprises an organic peroxide.

[0043] In a specific embodiment of the present invention, the initiator includes but is not limited to one or more of dicumyl peroxide, di-tert-butyl peroxide, phenylpropionic acid peroxide, tert-butyl peroxy-2-ethylhexyl carbonate, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane or tributyl peroxybenzoate.

[0044] In a specific embodiment of the present invention, the initiator is dicumyl peroxide and tert-butyl peroxide-2-ethylhexyl carbonate. Preferably, the mass ratio of dicumyl peroxide to tert-butyl peroxide-2-ethylhexyl carbonate is 1.5:1.

[0045] In a specific embodiment of the present invention, the initiator is di-tert-butyl peroxide and tert-butyl peroxy-2-ethylhexyl carbonate. Preferably, the mass ratio of di-tert-butyl peroxide to tert-butyl peroxy-2-ethylhexyl carbonate is 1:1.5.

[0046] In a specific embodiment of the present invention, the initiator is dicumyl peroxide and phenylpropionic acid peroxide. Preferably, the mass ratio of dicumyl peroxide to phenylpropionic acid peroxide is 1:1.

[0047] In a specific embodiment of the present invention, the initiator is 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane and tributyl peroxybenzoate. Preferably, the mass ratio of 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane to tributyl peroxybenzoate is 4:1.

[0048] Preferably, the added mass of the cross-linking agent is any value between 0% and 5% of the total mass of the degradable composite material (or its raw material), preferably any value between 0.5% and 2%, for example, 0%, 0.00001%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.25%, 2%, 3%, 4%, and 5%.

[0049] Preferably, the cross-linking agent includes an acrylate compound. Further preferably, the cross-linking agent includes but is not limited to one or more of pentaerythritol triacrylate, poly(ethylene-glycidyl methacrylate-co-methacrylate), ethylene-n-butyl acrylate, glycidyl methacrylate or diallyl titanate.

[0050] In a specific embodiment of the present invention, the crosslinking agent is pentaerythritol triacrylate and ethylene-n-butyl acrylate. Preferably, the mass ratio of pentaerythritol triacrylate to ethylene-n-butyl acrylate is 4:1.

[0051] In a specific embodiment of the present invention, the crosslinking agent is pentaerythritol triacrylate and poly (ethylene-glycidyl methacrylate-co-methacrylate), preferably, the mass ratio of pentaerythritol triacrylate to poly (ethylene-glycidyl methacrylate-co-methacrylate) is 1.5:1

[0052] In a specific embodiment of the present invention, the cross-linking agent is ethylene-n-butyl acrylate and glycidyl methacrylate. Preferably, the mass ratio of ethylene-n-butyl acrylate to glycidyl methacrylate is 1:1.

[0053] In a specific embodiment of the present invention, the cross-linking agent is poly(ethylene-glycidyl methacrylate-co-methacrylate) and diallyl titanate. Preferably, the mass ratio of poly(ethylene-glycidyl methacrylate-co-methacrylate) to diallyl titanate is 1:1.5.

[0054] Preferably, the added mass of the chain extender is any value between 0% and 5% of the total mass of the degradable composite material (or its raw material), preferably any value between 0.1% and 2%, for example, 0%, 0.00001%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, and 5%.

[0055] Preferably, the chain extender comprises a compound having an epoxy functional group. Further preferably, the chain extender includes but is not limited to one or more of a styrene-acrylic polymer having an epoxy functional group, an acrylic having a glycidyl group, a polyolefin, or a copolymer or oligomer of an acrylic having a glycidyl group and a polyolefin.

[0056] In a specific embodiment of the present invention, the chain extender is a styrene-acrylic polymer having an epoxy functional group.

[0057] In a specific embodiment of the present invention, the chain extender is an acrylic acid and / or polyolefin copolymer or oligomer having a glycidyl group.

[0058] In one embodiment of the present invention, the chain extender is a styrene-acrylic polymer having epoxy functional groups and an acrylic and / or polyolefin copolymer or oligomer having glycidyl groups.

[0059] Preferably, the styrene-acrylic polymer includes but is not limited to BASF ADR 4368, BASF ADR 4400, BASF ADR 4468, KANEKA MP-40 and the like.

[0060] Preferably, the acrylic and polyolefin copolymers or oligomers having glycidyl groups include but are not limited to Arkema LOTADER.

[0061] In a specific embodiment of the present invention, the chain extenders are BASF ADR4368 and BASF ADR4400. Preferably, the mass ratio of BASF ADR4368 to BASF ADR4400 is 1:1.

[0062] In a specific embodiment of the present invention, the chain extenders are BASF ADR 4400 and BASF ADR 4468. Preferably, the mass ratio of BASF ADR 4400 to BASF ADR 4468 is 7:3.

[0063] In a specific embodiment of the present invention, the chain extenders are BASF ADR 4400 and KANEKA MP-40. Preferably, the mass ratio of BASF ADR 4400 to KANEKA MP-40 is 3:2.

[0064] In a specific embodiment of the present invention, the chain extender is BASF ADR 4368 and Arkema LOTADER. Preferably, the mass ratio of BASF ADR 4368 to Arkema LOTADER is 2:3.

[0065] Preferably, the added mass of the anti-hydrolysis agent is any value between 0% and 5% of the total mass of the degradable composite material (or its raw material), preferably any value between 0.01% and 1%, for example, 0%, 0.00001%, 0.01%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, and 5%.

[0066] Preferably, the anti-hydrolysis agent includes but is not limited to carbodiimide and / or polycarbodiimide and the like.

[0067] In a specific embodiment of the present invention, the anti-hydrolysis agent is polycarbodiimide.

[0068] In a specific embodiment of the present invention, the anti-hydrolysis agent is polycarbodiimide and carbodiimide. Preferably, the mass ratio of the polycarbodiimide to carbodiimide is 4:1.

[0069] Preferably, the added mass of the antioxidant is any value between 0% and 5% of the total mass of the degradable composite material (or its raw material), preferably any value between 0.01% and 1%, for example, 0%, 0.00001%, 0.01%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, and 5%.

[0070] Preferably, the antioxidant includes but is not limited to one or more of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1010), octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1076) or tris(2,4-di-tert-butylphenyl) phosphite (antioxidant 168).

[0071] In a specific embodiment of the present invention, the antioxidant is antioxidant 1010.

[0072] In a specific embodiment of the present invention, the antioxidant is antioxidant 1076.

[0073] In a specific embodiment of the present invention, the antioxidants are antioxidant 1010 and antioxidant 168. Preferably, the mass ratio of the antioxidant 1010 to the antioxidant 168 is 3:1.

[0074] Preferably, the added mass of the thermal stabilizer is any value between 0% and 5% of the total mass of the degradable composite material (or its raw material), preferably any value between 0.01% and 1%, for example, 0%, 0.00001%, 0.01%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, and 5%.

[0075] Preferably, the heat stabilizer includes, but is not limited to, one or more of magnesium stearate, aluminum stearate, calcium stearate, zinc stearate, a ternary random copolymer of styrene-acrylonitrile-glycidyl methacrylate, or phosphate.

[0076] In a specific embodiment of the present invention, the thermal stabilizer is calcium stearate.

[0077] In a specific embodiment of the present invention, the heat stabilizer is magnesium stearate and zinc stearate. Preferably, the mass ratio of magnesium stearate to zinc stearate is 3:2.

[0078] In a specific embodiment of the present invention, the thermal stabilizer is sodium phosphate.

[0079] In a specific embodiment of the present invention, the heat stabilizer is a ternary random copolymer of styrene-acrylonitrile-glycidyl methacrylate.

[0080] In a specific embodiment of the present invention, the degradable composite material (or its raw material) is composed of polylactic acid and hydroxy fatty acid ester polymer.

[0081] In a specific embodiment of the present invention, the degradable composite material (or its raw materials) is composed of polylactic acid, poly-3-hydroxybutyrate, and flexible hydroxy fatty acid ester polymer.

[0082] In a specific embodiment of the present invention, the degradable composite material (or its raw materials) is composed of polylactic acid, poly-3-hydroxybutyrate, flexible hydroxy fatty acid ester polymer and additives.

[0083] In a specific embodiment of the present invention, the degradable composite material (or its raw material) comprises 20%-80% (preferably 40%-75%, further preferably any value in 50%-72%, for example 20%, 30%, 35%, 40%, 45%, 50%, 51%, 51.1%, 51.5%, 55%, 56%, 56.1%, 60%, 65%, 70%, 72%, 75%, 80%) of polylactic acid, 5%-50% (preferably 5%-40%, further preferably any value in 5%-35%, for example 5%, 6%, 10%, 15%, 17%, 20%, %, 25%, 26%, 27.6%, 30%, 35%, 40%, 45%, 50%) of poly-3-hydroxybutyrate, 5%-50% (preferably 5%-40%, more preferably any value between 5%-30%, for example 5%, 7%, 10%, 15%, 17%, 20%, 25%, 30%, 35%, 40%, 45%, 50%) of flexible hydroxy fatty acid ester polymer and 0%-5% (preferably 0.5%-4%, for example 0%, 0.1%. 0.5%, 1%, 1.5%, 2%, 2.5, 3%, 3.5%, 3.9%, 4%, 4.5%, 5%) of auxiliary agent.

[0084] In a specific embodiment of the present invention, the degradable composite material (or its raw materials) includes the following materials in parts by weight:

[0085] Polylactic acid: any value between 20 and 80 parts, preferably any value between 50 and 80 parts, for example, 20, 30, 35, 40, 45, 50, 51, 51.1, 51.5, 52, 53, 54, 55, 55.25, 55.5, 56, 56.1, 56.25, 56.5, 57, 58, 59, 60, 65, 70, 72, 75 or 80 parts;

[0086] Poly-3-hydroxybutyrate: any value between 5 and 50 parts, preferably any value between 5 and 35 parts, for example, 5 parts, 6 parts, 10 parts, 15 parts, 17 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 27.6 parts, 28 parts, 29 parts, 30 parts, 32 parts, 35 parts, 40 parts, 45 parts or 50 parts;

[0087] and,

[0088] Flexible hydroxy fatty acid ester polymer: any value in the range of 5-50 parts, preferably any value in the range of 5-30 parts, for example, 5 parts, 6 parts, 7 parts, 10 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts or 50 parts.

[0089] In a specific embodiment of the present invention, the degradable composite material (or its raw materials) comprises the following materials in parts by weight:

[0090] Polylactic acid: any value between 20 and 80 parts, preferably any value between 50 and 80 parts, for example, 20, 30, 35, 40, 45, 50, 51, 51.1, 51.5, 52, 53, 54, 55, 55.25, 55.5, 56, 56.1, 56.25, 56.5, 57, 58, 59, 60, 65, 70, 72, 75 or 80 parts;

[0091] Poly-3-hydroxybutyrate: any value between 5 and 50 parts, preferably any value between 5 and 35 parts, for example, 5 parts, 6 parts, 10 parts, 15 parts, 17 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 27.6 parts, 28 parts, 29 parts, 30 parts, 32 parts, 35 parts, 40 parts, 45 parts or 50 parts;

[0092] Flexible hydroxy fatty acid ester polymer: any value in the range of 5-50 parts, preferably any value in the range of 5-30 parts, for example, 5 parts, 6 parts, 7 parts, 10 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts or 50 parts; and,

[0093] Auxiliary agent: any value in the range of 0.00001-5 parts, preferably any value in the range of 0.1-5 parts, 0.00001 part, 0.0001 part, 0.01 part, 0.1 part, 0.5 part, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.1 parts, 3.2 parts, 3.3 parts, 3.4 parts, 3.5 parts, 3.6 parts, 3.7 parts, 3.8 parts, 3.9 parts, 4.0 parts, 4.1 parts, 4.2 parts, 4.3 parts, 4.4 parts, 4.5 parts, 4.6 parts, 4.7 parts, 4.8 parts, 4.9 parts or 5.0 parts.

[0094] Preferably, the degradable composite material (or its raw materials) can be prepared by any method in the prior art.

[0095] The second aspect of the present invention provides a method for preparing the degradable composite material according to the first aspect, the method comprising:

[0096] S1: mixing raw materials to obtain a mixture;

[0097] S2: The mixed material obtained in S1 is added to an extruder and extruded into strips, and then granulated.

[0098] Preferably, the extruder comprises a screw. Further preferably, the number of the screws is at least 1, at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 11 or at least 12.

[0099] The raw materials include a substrate.

[0100] Preferably, the raw materials further include an auxiliary agent. For example, in step S1, the base material and the auxiliary agent are mixed to obtain a mixture.

[0101] The types and addition amounts of the substrate and auxiliary agent are the same as those defined in the first aspect.

[0102] Preferably, the granulation further includes a cooling step.

[0103] Preferably, the cooling method includes air cooling or water cooling.

[0104] In a specific embodiment of the present invention, the cooling method is air cooling.

[0105] In a specific embodiment of the present invention, the cooling method is water cooling.

[0106] In a specific embodiment of the present invention, the preparation method comprises:

[0107] S1: mixing the raw materials (e.g., adding them to a mixer and mixing for 0.5-10 minutes) to obtain a mixture;

[0108] S2: The mixed material obtained in S1 is added to an extruder and extruded into strips, and then granulated. The obtained granules are the special material for biodegradable composite materials.

[0109] Preferably, the extruder comprises a screw. Further preferably, the number of the screws is at least 1, at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 11 or at least 12.

[0110] In a specific embodiment of the present invention, the number of the screws is 2, and the extruder is a twin-screw extruder.

[0111] Preferably, the heating temperature of the extruder in step S2 is any value in the range of 100°C to 180°C (preferably 140°C-180°C), for example, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C, 160°C, 165°C, 170°C, 175°C or 180°C.

[0112] Preferably, the granulation further includes a cooling step.

[0113] Further preferably, the cooling method includes air cooling or water cooling.

[0114] Preferably, the water cooling temperature is any value between -20°C and 70°C, for example, -20°C, -12°C, -15°C, -10°C, -5°C, 0°C, 5°C, 10°C, 15°C, 18°C, 20°C, 22°C, 25°C, 30°C, 32°C, 35°C, 37°C, 40°C, 45°C, 48°C, 50°C, 55°C, 60°C, 65°C, 67°C or 70°C.

[0115] Preferably, the air cooling is any value between -15°C and 75°C, for example, -15°C, -10°C, -8°C, -5°C, 0°C, 3°C, 5°C, 10°C, 15°C, 18°C, 20°C, 25°C, 30°C, 32°C, 35°C, 40°C, 42°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 72°C or 75°C.

[0116] In a specific embodiment of the present invention, the preparation method comprises:

[0117] S1: adding polylactic acid, poly-3-hydroxybutyrate, flexible hydroxy fatty acid ester polymer, and additives into a high-speed mixer and mixing for 0.5 min to 10 min (e.g., 0.5 min, 2 min, 2.5 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min or 10 min) to obtain a mixture;

[0118] S2: adding the mixed material obtained in S1 into a twin-screw extruder, extruding it into strips at a temperature of 100°C-180°C (preferably 140°C-180°C), cooling it under air cooling or water cooling conditions, and then granulating it. The obtained pellets are the special material for biodegradable composite materials.

[0119] In a specific embodiment of the present invention, the preparation method comprises:

[0120] S1: any value between 20% and 80% of the total mass (preferably between 40% and 75%, more preferably between 50% and 72%), for example, 20%, 30%, 35%, 40%, 45%, 50%, 51%, 51.1%, 51.5%, 55%, 55.25%, 56%, 56.1%, 56.25%, 56.5%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 100%, 101%, 102%, 103%, 104%, 105%, 106%, 107%, 108%, 109%, 110%, 111%, 112%, 113%, 114%, 115%, 116%, 117%, 118%, 119%, 120%, 121%, 122%, 123%, 124%, 125%, 126%, 127%, 128%, 129%, 130%, 131%, 132%, 133%, 134%, 135 5%, 70%, 72%, 75%, 80%) of polylactic acid, 5%-50% (preferably 5%-40%, more preferably any value between 5%-35%, for example, 5%, 6%, 10%, 15%, 17%, 20%, 25%, 26%, 27.6%, 28%, 29%, 30%, 35%, 40%, 45%, 50%) of poly-3-hydroxybutyrate, 5% to 50% (preferably 5% to 40%, more preferably any value in 5% to 30%, for example 5%, 7%, 10%, 15%, 16%, 17%, 18%, 19%, 20%, 25%, 30%, 35%, 40%, 45%, 50%) of the total mass of the flexible hydroxy fatty acid ester polymer and 0% to 5% (for example 0%, 0.1%, 0.5%, 1%) of the total mass of the flexible hydroxy fatty acid ester polymer. , 1.5%, 2%, 2.5%, 3%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 4%, 4.5%, 5%) of the auxiliary agent are added into a high-speed mixer and mixed at a high speed for 0.5-10 min (for example, 0.5, 2, 2.5, 3, 4, 5, 6, 7, 8, 9 or 10 min) to obtain a mixture;

[0121] S2: adding the mixed material obtained in S1 into a twin-screw extruder, heating the mixed material to a temperature of 100-180°C (preferably 140-180°C) for reaction extrusion, cooling the mixed material into strips by air cooling or water cooling, and granulating the mixed material after cooling. The obtained granules are the special material for degradable composite materials.

[0122] The third aspect of the present invention provides a degradable composite material obtained by the above preparation method.

[0123] The fourth aspect of the present invention provides an application of any of the above-mentioned degradable composite materials, and / or the degradable composite materials obtained by the above-mentioned preparation method, wherein the application includes application in the preparation of downstream products.

[0124] Preferably, the downstream products include but are not limited to one or more of fabrics, lunch boxes, cups, straws, packaging materials or medical instruments, etc.

[0125] Depending on the requirements of the specific implementation, the downstream product may have a pattern or no pattern.

[0126] The term "include" or "comprising" in the present invention is an open description containing the specified components or steps described, as well as other specified components or steps that do not substantially affect them.

[0127] The term "and / or" in this invention includes all combinations of the items connected by the term, and each combination should be considered to have been listed separately herein. For example, "A and / or B" includes "A," "A and B," and "B." For another example, "A, B and / or C" includes "A," "B," "C," "A and B," "A and C," "B and C," and "A and B and C."

[0128] The abbreviations and full names of the present invention are compared in Table 1 below.

[0129] Table 1: Abbreviation and full name comparison table

[0130] Through the above technical solution, the present invention has the following advantages:

[0131] (1) The present invention uses poly-3-hydroxybutyrate to form a heat-resistant network skeleton, thereby increasing the softening temperature of the entire material; a flexible hydroxy fatty acid ester polymer is dispersed in polylactic acid to form a stress-absorbing sea-island structure, thereby improving the toughness and coloring and dyeing properties of the material; the three main materials play a synergistic role, making the degradable composite material have high toughness, high heat resistance, easy dyeing and good mechanical properties;

[0132] (2) The present invention uses initiators and crosslinking agents to improve the interfacial compatibility between materials and further enhance the various properties of the materials. Experiments have confirmed that the use of initiators and crosslinking agents significantly improves the comprehensive properties of the degradable composite material, with a synergistic effect.

[0133] (3) The flexible hydroxy fatty acid ester polymer in the present invention is used in a moderate amount, achieving a good toughening effect without sacrificing high temperature resistance and some mechanical properties, and reducing costs. Experiments have confirmed that if the flexible hydroxy fatty acid ester polymer is used in too high an amount, the heat resistance and strength of the material will be reduced; if the amount is too low, the toughness and coloring and dyeing properties will not be significantly improved;

[0134] (4) The present invention uses a chain extender to effectively increase the molecular weight of the material and reduce the loss of material performance; uses an anti-hydrolysis agent and a thermal stabilizer to improve the thermal processing performance of the material and reduce thermal degradation during the later thermal processing. The combined use of these three additives can improve the comprehensive performance of the degradable composite material;

[0135] (5) The present invention uses air cooling for granulation, which avoids the later water removal process, has low energy consumption, low cost, fast process, and also ensures the stability of the composite material product;

[0136] (6) The materials and preparation method of the present invention are low in cost, and the production process is simple and easy to control, which is conducive to industrial production. DETAILED DESCRIPTION

[0137] To make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the present invention is described in more detail below through specific examples and comparative examples, but the present invention is in no way limited by these examples. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0138] Sources of materials used in the present invention: Unless otherwise specified, the materials used in the examples of the present invention can be obtained commercially.

[0139] Unless otherwise specified, the parts, percentages or ratios described in the embodiments of the present invention are all based on mass.

[0140] The test standards of various indicators in the embodiments and comparative examples are shown in Table 2 below:

[0141] Table 2

[0142] Example 1: Preparation of PLA / PHA (PHB+P34HB) composite material

[0143] 55% PLA, 26% PHB, 15% P3HB4HB (4HB content 20 mol%), 0.15% dicumyl peroxide, 0.1% tert-butyl peroxy-2-ethylhexyl carbonate, 1% pentaerythritol triacrylate, 0.25% ethylene-n-butyl acrylate, 0.5% BASF ADR4368, 0.5% BASF ADR4400, 0.5% polycarbodiimide, 0.5% antioxidant 1010, and 0.5% calcium stearate are added to a high-speed mixer and mixed at high speed for 2 minutes to achieve thorough mixing. The pre-mixed materials are then added to a twin-screw extruder, heated to 140-180°C for reaction extrusion, air-cooled into strands, and then pelletized to obtain a biodegradable composite material that can be directly used in downstream injection molding, extrusion, blown film, cast film, and other processed products.

[0144] The obtained materials were tested and the results are shown in Table 3.

[0145] Table 3: Test data of PLA / PHA (PHB+P34HB) composite materials

[0146] Example 2: Preparation of PLA / PHA (PHB+P34HB) composites with different ratios

[0147] 51.5% by mass of PLA, 27.6% of PHB, 17% of P3HB4HB (4HB content 15 mol%), 0.1% of di-tert-butyl peroxide, 0.15% of tert-butyl peroxy-2-ethylhexyl carbonate, 0.75% of pentaerythritol triacrylate, 0.5% of poly(ethylene-glycidyl methacrylate-co-methacrylate), 0.7% of BASF ADR 4400, 0.3% of BASF ADR 4468, 0.4% of polycarbodiimide, 0.1% of carbodiimide, 0.4% of antioxidant 1076, 0.3% of magnesium stearate and 0.2% of zinc stearate were added to a high-speed mixer and mixed at high speed for 2.5 minutes to ensure thorough mixing. The premixed materials are added to a twin-screw extruder, heated to 140-180°C for reaction extrusion, air-cooled to form strips, and then pelletized to obtain biodegradable composite materials, which can be directly used for downstream injection molding, extrusion, blown film and cast film products.

[0148] The obtained materials were tested and the results are shown in Table 4.

[0149] Table 4: Test data of PLA / PHA (PHB+P34HB) composites with different ratios

[0150] Example 3: Preparation of PLA / PHA (PHB+PHBV) composite material

[0151] 51.1% PLA, 25% PHB, 20% PHBV (3HV content 15 mol%), 0.125% dicumyl peroxide, 0.125% phenylpropionic acid peroxide, 0.625% ethylene-n-butyl acrylate, 0.625% glycidyl methacrylate, 0.6% BASF ADR 4400, 0.4% KANEKA MP-40, 0.5% polycarbodiimide, 0.3% antioxidant 1010, 0.1% antioxidant 168, and 0.5% sodium phosphate were added to a high-speed mixer and mixed at high speed for 0.5 minutes to achieve thorough mixing. The pre-mixed materials were then added to a twin-screw extruder, heated to 140-180°C for reaction extrusion, air-cooled into strands, and pelletized to obtain a biodegradable composite material that can be directly used in downstream injection molding, extrusion, blown film, and cast film processing products. The obtained materials were tested and the results are shown in Table 5.

[0152] Table 5: Test data of PLA / PHA (PHB+PHBV) composite materials

[0153] Example 4: Preparation of PLA / PHA (PHB+PHBHHx) composite material

[0154] 56.1% PLA, 25% PHB, 15% PHBHHx (3HHx content 20 mol%), 0.2% 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 0.05% tributyl peroxybenzoate, 0.5% poly(ethylene-glycidyl methacrylate-co-methacrylate), 0.75% diallyl titanate, 0.4% BASF ADR 4368, 0.6% Arkema LOTADER, 0.4% polycarbodiimide, 0.1% carbodiimide, 0.4% antioxidant 1010, and 0.5% styrene-acrylonitrile-glycidyl methacrylate ternary random copolymer were added to a high-speed mixer and mixed at high speed for 10 minutes to ensure thorough mixing. The premixed materials were added to a twin-screw extruder, heated to 140-180°C for reaction extrusion, air-cooled into strands, and then pelletized to produce a biodegradable composite material. This composite material can be directly used in downstream injection molding, extrusion, blown film, and cast film processes. The resulting material was tested, and the results are shown in Table 6.

[0155] Table 6: Test data of PLA / PHA (PHB+PHBHHx) composites

[0156] Example 5: Preparation of PLA / PHA (PHB+P34HB) composite material

[0157] 55 parts by weight of PLA, 26 parts of PHB, and 15 parts of P3HB4HB (4HB content 20 mol%) were added to a high-speed mixer and mixed at high speed for 2 minutes to ensure thorough mixing. The premixed materials were then added to a twin-screw extruder, heated to 140-180°C for reaction extrusion, air-cooled into strands, and pelletized to obtain a PLA / PHA composite.

[0158] The obtained materials were tested and the results are shown in Table 7.

[0159] Table 7: Test data of PLA / PHA (PHB+P34HB) composites

[0160] Example 6: Preparation of PLA / PHA (PHB+P34HB) composite material

[0161] 55 parts by weight of PLA, 26 parts of PHB, 15 parts of P3HB4HB (4HB content 20 mol%), 0.15 parts of dicumyl peroxide, 0.1 parts of tert-butyl peroxy-2-ethylhexyl carbonate, 1 part of pentaerythritol triacrylate, and 0.25 parts of ethylene-n-butyl acrylate were added to a high-speed mixer and mixed at high speed for 2 minutes to achieve thorough mixing. The premixed materials were then added to a twin-screw extruder, heated to 140-180°C for reaction extrusion, air-cooled into strands, and pelletized to obtain a PLA / PHA composite.

[0162] The obtained materials were tested and the results are shown in Table 8.

[0163] Table 8: Test data of PLA / PHA (PHB+P34HB) composites

[0164] Example 7: Preparation of PLA / PHA (PHB+P34HB) composite material

[0165] 55 parts by weight of PLA, 26 parts of PHB, 15 parts of P3HB4HB (4HB content 20 mol%), 0.5 parts of BASF ADR4368, 0.5 parts of BASF ADR4400, 0.5 parts of polycarbodiimide, and 0.5 parts of calcium stearate were added to a high-speed mixer and mixed at high speed for 2 minutes to thoroughly mix. The premixed materials were then added to a twin-screw extruder, heated to 140-180°C for reaction extrusion, air-cooled into strands, and pelletized to obtain a PLA / PHA composite material that can be directly used in downstream processes such as injection molding, extrusion, blown film, and cast film.

[0166] The obtained materials were tested and the results are shown in Table 9.

[0167] Table 9: Test data of PLA / PHA (PHB+P34HB) composites

[0168] Example 8: Preparation of PLA / PHA (PHB+P34HB) composite material

[0169] The formulation and process are the same as those in Example 1, except that no initiator or cross-linking agent is added (the balance is supplemented by polylactic acid). The obtained material was tested and found to have a thermal softening temperature of 95°C, a tensile elongation at break of 24%, a melt index within the range of 6-13, meeting the requirements of downstream products, and an Izod notched impact strength of 8.8 kJ / m 2 ), dyeing uniformity (5 levels).

[0170] Example 9: Preparation of PLA / PHA (PHB+P34HB) composite material

[0171] The formulation and process were the same as in Example 1, except that no chain extender was added (the remainder was made up of PLA). Testing of the resulting material revealed a thermal softening temperature of 97°C, a tensile elongation at break of 25.8%, a melt index within the range of 6-13, meeting downstream product requirements, and dyeing uniformity of 4-5.

[0172] Example 10: Preparation of PLA / PHA (PHB+P34HB) composite material

[0173] The formulation and process were the same as in Example 1, except that no anti-hydrolysis agent was added (the remainder was made up of PLA). Testing of the resulting material revealed a thermal softening temperature of 99°C, a tensile elongation at break of 26.2%, a melt index within the range of 6-13, meeting downstream product requirements, and dyeing uniformity of Grade 5.

[0174] Example 11: Preparation of PLA / PHA (PHB+P34HB) composite material

[0175] The formulation and process were the same as in Example 1, except that no heat stabilizer was added (the balance was made up of PLA). Testing of the resulting material revealed a thermal softening temperature of 94°C, a tensile elongation at break of 23.7%, a melt index within the range of 6-13, meeting downstream product requirements, and dyeing uniformity of Grade 5.

[0176] Example 12: Preparation of PLA / PHA (PHB+P34HB) composite material

[0177] The formulation was the same as in Example 1, except that the strands were cooled with water, dried in an oven, and then pelletized. Testing of the resulting material revealed a thermal softening temperature of 101°C, a tensile elongation at break of 21.5%, a melt index within the range of 6-13, meeting downstream product requirements, and dyeing uniformity of grade 5.

[0178] Example 13: Preparation of PLA / PHA (PHB+P34HB) composite material

[0179] The formulation and process are the same as in Example 1, except that no initiator is added (the balance is supplemented with PLA).

[0180] The obtained material has been tested and found to have a thermal softening temperature of 100°C, tensile elongation at break of 26.9%, a melt index within the range of 6-13, meeting the needs of downstream products, and an Izod notched impact strength of 9.8KJ / m 2 ), dyeing uniformity (5 levels).

[0181] Example 14: Preparation of PLA / PHA (PHB+P34HB) composite material

[0182] The formulation and process are the same as in Example 1, except that no cross-linking agent is added (the balance is supplemented with PLA).

[0183] The obtained material has been tested and found to have a thermal softening temperature of 99°C, tensile elongation at break of 25.4%, a melt index within the range of 6-13, meeting the needs of downstream products, and an Izod notched impact strength of 9.5KJ / m 2 ), dyeing uniformity (5 levels).

[0184] Example 15: Preparation of PLA / PHA (PHB+P34HB) composite material

[0185] 60 parts by weight of PLA, 6 parts by weight of PHB, 30 parts by weight of P3HB4HB (4HB content 5 mol%), 0.15 parts by weight of dicumyl peroxide, 0.1 parts by weight of tert-butyl peroxy-2-ethylhexyl carbonate, 1 part by weight of pentaerythritol triacrylate, 0.25 parts by weight of ethylene-n-butyl acrylate, 0.5 parts by weight of BASF ADR4368, 0.5 parts by weight of BASF ADR4400, 0.5 parts by weight of polycarbodiimide, 0.5 parts by weight of antioxidant 1010, and 0.5 parts by weight of calcium stearate are added to a high-speed mixer and mixed at high speed for 2 minutes to achieve thorough mixing. The pre-mixed materials are then added to a twin-screw extruder, heated to 140-180° C. for reaction extrusion, air-cooled into strands, and then pelletized to obtain a biodegradable composite material that can be directly used in downstream injection molding, extrusion, blown film, cast film, and other processed products.

[0186] The obtained materials were tested and the results are shown in Table 10.

[0187] Table 10: Test data of PLA / PHA (PHB+P34HB) composites

[0188] Example 16: Preparation of PLA / PHA (PHB+P34HB) composite material

[0189] 56 parts by weight of PLA, 35 parts by weight of PHB, 5 parts by weight of P3HB4HB (4HB content 50 mol%), 0.15 parts by weight of dicumyl peroxide, 0.1 parts by weight of tert-butyl peroxy-2-ethylhexyl carbonate, 1 part by weight of pentaerythritol triacrylate, 0.25 parts by weight of ethylene-n-butyl acrylate, 0.5 parts by weight of BASF ADR4368, 0.5 parts by weight of BASF ADR4400, 0.5 parts by weight of polycarbodiimide, 0.5 parts by weight of antioxidant 1010, and 0.5 parts by weight of calcium stearate are added to a high-speed mixer and mixed at high speed for 2 minutes to achieve thorough mixing. The pre-mixed materials are then added to a twin-screw extruder, heated to 140-180° C. for reaction extrusion, air-cooled into strands, and then pelletized to obtain a biodegradable composite material that can be directly used for downstream processing products such as injection molding, extrusion, blown film, and cast film.

[0190] The obtained materials were tested and the results are shown in Table 11.

[0191] Table 11: Test data of PLA / PHA (PHB+P34HB) composites

[0192] Example 17: Preparation of PLA / PHA (PHB+P34HB) composite material

[0193] 72 parts by weight of PLA, 17 parts by weight of PHB, 7 parts by weight of P3HB4HB (4HB content 50 mol%), 0.15 parts by weight of dicumyl peroxide, 0.1 parts by weight of tert-butyl peroxy-2-ethylhexyl carbonate, 1 part by weight of pentaerythritol triacrylate, 0.25 parts by weight of ethylene-n-butyl acrylate, 0.5 parts by weight of BASF ADR4368, 0.5 parts by weight of BASF ADR4400, 0.5 parts by weight of polycarbodiimide, 0.5 parts by weight of antioxidant 1010, and 0.5 parts by weight of calcium stearate are added to a high-speed mixer and mixed at high speed for 2 minutes to achieve thorough mixing. The pre-mixed materials are then added to a twin-screw extruder, heated to 140-180° C. for reaction extrusion, air-cooled into strands, and then pelletized to obtain a biodegradable composite material that can be directly used in downstream injection molding, extrusion, blown film, cast film, and other processed products.

[0194] The obtained materials were tested and the results are shown in Table 12.

[0195] Table 12: Test data of PLA / PHA (PHB+P34HB) composites

[0196] Comparative Example 1: Preparation of unmodified PLA material

[0197] The properties of the unmodified PLA material were tested, and the results showed that the thermal softening temperature (53°C), tensile elongation at break (2.2%), and Izod notched impact strength (1.5KJ / m 2 ) and dyeing uniformity (grade 1-2).

[0198] Comparative Example 2: Preparation of PLA / PHA (PHB+P34HB) composite material with excessively high P3HB4HB ratio compared to Example 1

[0199] 55% PLA, 6% PHB, 35% P3HB4HB (4HB content 20 mol%), 0.15% dicumyl peroxide, 0.1% tert-butyl peroxy-2-ethylhexyl carbonate, 1% pentaerythritol triacrylate, 0.25% ethylene-n-butyl acrylate, 0.5% BASF ADR4368, 0.5% BASF ADR4400, 0.5% polycarbodiimide, 0.5% antioxidant 1010, and 0.5% calcium stearate were added to a high-speed mixer and mixed at high speed for 2 minutes to achieve thorough mixing. The premixed materials were then added to a twin-screw extruder, heated to 140-180°C for reaction extrusion, air-cooled into strands, and pelletized to obtain a PLA / PHA composite material.

[0200] The obtained material was tested to obtain its thermal softening temperature (85°C) and tensile elongation at break (67.2%).

[0201] Comparative Example 3: Preparation of PLA / PHA (PHB+P34HB) composite material with too low P3HB4HB ratio compared with Example 1

[0202] PLA / PHA composite material was prepared by adding 55% PLA, 36% PHB, 5% P3HB4HB (4HB content 20 mol%), 0.15% dicumyl peroxide, 0.1% tert-butyl peroxy-2-ethylhexyl carbonate, 1% pentaerythritol triacrylate, 0.25% ethylene-n-butyl acrylate, 0.5% BASF ADR4368, 0.5% BASF ADR4400, 0.5% polycarbodiimide, 0.5% antioxidant 1010, and 0.5% calcium stearate to a high-speed mixer and mixing at high speed for 2 minutes to achieve thorough mixing. The premixed materials were then added to a twin-screw extruder, heated to 140-180°C for reaction extrusion, air-cooled into strands, and pelletized to obtain a PLA / PHA composite material.

[0203] The obtained material was tested and its tensile elongation at break (18.6%), Izod notched impact strength (4.2KJ / m 2 ), dyeing uniformity (grade 2-3).

[0204] Comparative Example 4: Preparation of PLA / P34HB Composite Material (Compared with Example 1, PHB was not added and the ratio of PLA to P34HB remained unchanged)

[0205] PLA (75.5%), P3HB4HB (20 mol%), 0.15% dicumyl peroxide, 0.1% tert-butyl peroxy-2-ethylhexyl carbonate, 1% pentaerythritol triacrylate, 0.25% ethylene-n-butyl acrylate, 0.5% BASF ADR4368, 0.5% BASF ADR4400, 0.5% polycarbodiimide, 0.5% antioxidant 1010, and 0.5% calcium stearate were added to a high-speed mixer and mixed at high speed for 2 minutes to achieve thorough mixing. The premixed materials were then added to a twin-screw extruder, heated to 140-180°C for reaction extrusion, air-cooled into strands, and pelletized to obtain a PLA / P34HB composite material.

[0206] The obtained material was tested and its thermal softening temperature was found to be 62.5°C.

[0207] Comparative Example 5: Preparation of PLA / PHB Composite Material (Compared with Example 1, P34HB was not added and the ratio of PLA to PHB remained unchanged)

[0208] 65% PLA, 31% PHB, 0.15% dicumyl peroxide, 0.1% tert-butyl peroxy-2-ethylhexyl carbonate, 1% pentaerythritol triacrylate, 0.25% ethylene-n-butyl acrylate, 0.5% BASF ADR4368, 0.5% BASF ADR4400, 0.5% polycarbodiimide, 0.5% antioxidant 1010, and 0.5% calcium stearate were added to a high-speed mixer and mixed at high speed for 2 minutes to achieve thorough mixing. The premixed materials were then added to a twin-screw extruder, heated to 140-180°C for reaction extrusion, air-cooled into strands, and pelletized to obtain a PLA / PHA composite.

[0209] The obtained material was tested and its tensile elongation at break (6.8%), Izod notched impact strength (1.7KJ / m 2 ) and dyeing uniformity (grade 2-3).

[0210] As can be seen from Example 5 and Comparative Example 1, the overall performance of the biodegradable composite material after compounding PHB, P34HB, and PLA is significantly improved compared to unmodified PLA, and the addition of additives can further improve various properties. The present invention utilizes specific components and contents to prepare a biodegradable composite material with significantly improved thermal softening temperature, elongation at break, and notched Izod impact strength. The melt index is controlled within an appropriate range, improving the material's toughness and operating temperature. It also exhibits excellent dyeing performance and dyeing uniformity. Furthermore, the biodegradable composite material of the present invention has low material costs and a simple, easily controllable production process, making it suitable for industrial production.

[0211] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A degradable composite material, characterized in that: The degradable composite material comprises a substrate, wherein the substrate comprises: polylactic acid and a hydroxy fatty acid ester polymer. The hydroxy fatty acid ester polymer includes poly-3-hydroxybutyrate and a flexible hydroxy fatty acid ester polymer, the elongation at break of the flexible hydroxy fatty acid ester polymer is greater than or equal to 20%, and the melt index is greater than or equal to 1g / 10min, and the mass ratio of the poly-3-hydroxybutyrate to the flexible hydroxy fatty acid ester polymer is (0.2-7):

1.

2. The degradable composite material according to claim 1, characterized in that: The mass ratio of the poly-3-hydroxybutyrate to the flexible hydroxy fatty acid ester polymer is (0.5-4):1, preferably (1-2):

1.

3. The degradable composite material according to claim 1 or 2, characterized in that: The flexible hydroxy fatty acid ester polymer comprises one or more of P3HP, P(HA-LA), PHV, P34HB, PHBV, PHBHHx, PHBHHp, PHO, PHN, PHD, P3HB4HB3HV or P3HB4HB5HV.

4. The degradable composite material according to any one of claims 1 to 3, characterized in that: The monomers of the flexible hydroxy fatty acid ester polymer include 3HB, and the molar content of the monomers other than 3HB in the flexible hydroxy fatty acid ester polymer is 1-50%, more preferably 5-50%.

5. The degradable composite material according to any one of claims 1 to 4, characterized in that: In the substrate, the mass ratio of polylactic acid to hydroxy fatty acid ester polymer is (1-3):1, preferably (1-2):1, and more preferably (1-1.5):

1.

6. The degradable composite material according to any one of claims 1 to 5, characterized in that: The mass of the polylactic acid is 20%-80% of the total mass of the degradable composite material, preferably 40%-75%, and further preferably 50%-72%.

7. The degradable composite material according to any one of claims 1 to 6, characterized in that: The mass of the poly-3-hydroxybutyrate is 5%-50% of the total mass of the degradable composite material, preferably 5%-40%, and more preferably 5%-35%.

8. The degradable composite material according to any one of claims 1 to 7, characterized in that: The mass of the flexible hydroxy fatty acid ester polymer is 5%-50% of the total mass of the degradable composite material, preferably 5%-40%, and more preferably 5%-30%.

9. The degradable composite material according to any one of claims 1 to 8, characterized in that: The degradable composite material further comprises an auxiliary agent; Preferably, the mass of the auxiliary agent is 0%-5%, preferably 0.5-4% of the total mass of the degradable composite material.

10. The degradable composite material according to claim 9, characterized in that: The auxiliary agent comprises one or more of an initiator, a cross-linking agent, a chain extender, an anti-hydrolysis agent, an antioxidant or a heat stabilizer; Preferably, the initiator comprises a peroxide; further preferably, the initiator comprises an organic peroxide; more preferably, the initiator comprises one or more of dicumyl peroxide, di-tert-butyl peroxide, phenylpropionic acid peroxide, tert-butyl peroxy-2-ethylhexyl carbonate, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane or tributyl peroxybenzoate; Preferably, the crosslinking agent comprises an acrylate compound, and further preferably, the crosslinking agent comprises one or more of pentaerythritol triacrylate, poly(ethylene-glycidyl methacrylate-co-methacrylate), ethylene-n-butyl acrylate, glycidyl methacrylate or diallyl titanate; Preferably, the chain extender comprises a compound having an epoxy functional group, and further preferably, the chain extender comprises one or more of a styrene-acrylic polymer having an epoxy functional group, an acrylic having a glycidyl group, a polyolefin, or a copolymer or oligomer of an acrylic having a glycidyl group and a polyolefin; Preferably, the anti-hydrolysis agent comprises carbodiimide and / or polycarbodiimide; Preferably, the antioxidant comprises one or more of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate) or tris(2,4-di-tert-butylphenyl) phosphite; Preferably, the heat stabilizer comprises one or more of magnesium stearate, aluminum stearate, calcium stearate, zinc stearate, a ternary random copolymer of styrene-acrylonitrile-glycidyl methacrylate, or phosphate.

11. A method for preparing the degradable composite material according to any one of claims 1 to 10, characterized in that: The preparation method comprises: S1: mixing raw materials to obtain a mixed material; S2: adding the mixed material obtained in S1 into an extruder, extruding it into strips, and then granulating it; The raw materials include a substrate; Preferably, the raw materials contain auxiliary agents.

12. The preparation method according to claim 11, characterized in that: The preparation method comprises: S1: mixing the raw materials (for example, adding them into a mixer and mixing for 0.5-10 minutes) to obtain a mixed material; S2: adding the mixed material obtained in S1 into an extruder, extruding it into strips at a temperature of 100°C-180°C, cooling it under air cooling or water cooling conditions, and then granulating it.

13. A use of the degradable composite material according to any one of claims 1 to 10, and / or the degradable composite material obtained by the preparation method according to any one of claims 11 to 12, characterized in that: The application includes application in the preparation of downstream products.

14. The use according to claim 13, characterized in that The downstream products include one or more of fabrics, lunch boxes, cups, straws, packaging materials or medical instruments.

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