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CN-121975117-A - Bottle brush polymer for toughening rigid biodegradable polyester, toughening composition thereof, preparation method and application

CN121975117ACN 121975117 ACN121975117 ACN 121975117ACN-121975117-A

Abstract

The invention discloses a bottle brush polymer for toughening rigid biodegradable polyester, a toughening composition thereof, a preparation method and application. The bottle brush polymer has a polythiooctanoic acid backbone and flexible polyester side chains grafted thereto, and optionally rigid polyester side chains, when grafted, flexible side chains must be present simultaneously. The bottle brush polymer can be uniformly dispersed in the polyester matrix through the volume exclusion effect and brush-like distribution structure of the dense side chains, so that the energy dissipation is realized, the elongation at break and the impact toughness are obviously improved, and when the rigid polyester chain segment which is the same as the matrix is introduced into the side chains, the interface compatibility can be further improved, and the balance between the rigidity and the toughness is realized. The bottle brush polymer is prepared by ring-opening polymerization of bio-based small molecular lipoic acid, has simple preparation steps and biodegradability, and is suitable for the fields of disposable products, packaging materials, medical degradable instruments and the like.

Inventors

  • HUANG JING
  • ZHAO MENGFEI
  • DONG WEIFU
  • LI TING
  • ZHANG XUHUI
  • WANG YANG

Assignees

  • 江南大学

Dates

Publication Date
20260505
Application Date
20260211

Claims (10)

  1. 1. A bottle brush polymer for toughening rigid biodegradable polyester is characterized in that the main chain of the bottle brush polymer is poly lipoic acid, and the side chain is a flexible polyester side chain or a flexible polyester side chain and a rigid biodegradable polyester side chain.
  2. 2. The bottle brush polymer for toughening rigid biodegradable polyester according to claim 1, wherein the flexible polyester side chain is derived from one or a combination of more than two of polycaprolactone, polybutylene terephthalate, polybutylene succinate and aliphatic polycarbonate, the rigid biodegradable polyester side chain is derived from one of polylactic acid, polyhydroxyalkanoate and polyglycolic acid, the weight average molecular weight of the side chain ranges from 500 daltons to 10000 daltons, and the mass ratio of the rigid biodegradable polyester side chain to the whole side chain ranges from 0% to 50%.
  3. 3. A process for the preparation of a bottle brush polymer for toughening rigid biodegradable polyesters according to any one of claims 1-2, characterized in that said process comprises the steps of: (1) Dissolving single hydroxyl-terminated polyester and lipoic acid in a solvent, stirring uniformly, sequentially adding a Steglich esterification coupling agent and an organic base catalyst, reacting, respectively washing with hydrochloric acid solution, saturated sodium bicarbonate solution, water and saturated saline water after the reaction is finished, and finally obtaining lipoic acid modified polyester macromonomer through vacuum drying; (2) And (3) dissolving the lipoic acid modified polyester macromer prepared in the step (1) in a solvent, and reacting under ultraviolet irradiation to obtain the bottle brush polymer.
  4. 4. The method according to claim 3, wherein the single hydroxyl-terminated polyester and lipoic acid in the step (1) are fed in a molar ratio of carboxyl to hydroxyl of (1-1.5): 1, the steglich esterification coupling agent is fed in a molar ratio of (1-1.5): 1, and the organic base catalyst is fed in a molar ratio of (1-1.5): 1.
  5. 5. The process according to claim 3, wherein the Steglich esterification coupling agent in step (1) is one or a combination of N, N' -dicyclohexylcarbodiimide or 1-ethyl- (3-dimethylaminopropyl) carbodiimide hydrochloride, the organic base catalyst is 4-dimethylaminopyridine, and the solvent in steps (1) and (2) is one or a combination of more than two of dichloromethane, chloroform, tetrahydrofuran, dimethyl sulfoxide and N, N-dimethylformamide.
  6. 6. The preparation method of the ultraviolet light source according to claim 3, wherein the reaction time in the step (1) is 12-24 hours, the reaction temperature is 0-40 ℃, the ultraviolet light irradiation condition in the preparation step (2) is 365-420 nm, the irradiation time is 3-12 hours, and the irradiation temperature is 25-60 ℃.
  7. 7. A toughening composition comprising a rigid biodegradable polyester and a brush polymer according to any one of claims 1 to 2, or a brush polymer according to any one of claims 3 to 6, the brush polymer having a mass content of from 5 to 30 wt%.
  8. 8. A method of preparing a toughening composition according to claim 7, comprising the steps of: ① Melt blending the bottle brush polymer with the rigid biodegradable polyester to form a toughening composition material; ② And (3) molding the toughening composition material to obtain the toughening composition.
  9. 9. The method of claim 8, wherein in step ①, the rigid biodegradable polyester is one of polylactic acid, polyhydroxyalkanoate, and polyglycolic acid, the melt blending temperature is 160-230 ℃ and the time is 3-10 min, and in step ②, the molding process is selected from extrusion, injection molding, tabletting, and 3D printing, the molding temperature is 160-230 ℃, and the molding time is 3-10 min.
  10. 10. Use of the toughening composition of claim 7 or the toughening composition prepared by the preparation method of any of claims 8 to 9, in packaging materials, disposable articles or medical degradable devices.

Description

Bottle brush polymer for toughening rigid biodegradable polyester, toughening composition thereof, preparation method and application Technical Field The invention relates to the technical field of general plastics and the field of composite materials, in particular to a bottle brush polymer for toughening rigid biodegradable polyester, a toughening composition, a preparation method and application thereof. Background In recent years, biodegradable polyesters represented by polylactic acid (PLA), polyhydroxyalkanoate (PHA) and polyglycolic acid (PGA) have been widely paid attention to and used in the fields of packaging materials, medical consumables, disposable products, and the like because of their advantages such as good biocompatibility and high mechanical strength. However, the polyester material has the inherent defects of low elongation at break, insufficient impact toughness, obvious brittle fracture and the like, and severely restricts the further popularization. Aiming at the problem of insufficient toughness of rigid biodegradable polyester, the prior art mainly adopts a strategy of chemical modification and physical modification. Among them, the chemical modification method can improve the ductility of the material on a molecular scale, but generally requires multi-step reaction, strict reaction conditions and a special catalytic system, and has complex process, high cost and difficult adaptation to the existing large-scale industrial processing flow. In contrast, the introduction of plasticizers or flexible polymers as toughening phases by means of physical blending has received considerable attention due to the simple process and ease of implementation. However, existing physical toughening approaches still have significant limitations. On the one hand, the low-molecular or small-molecular plasticizer often needs higher addition amount to obtain obvious toughening effect, which easily leads to obvious reduction of rigidity of the material, and has migration risk in long-term use or thermal processing process, thus affecting mechanical stability and service life of the product. On the other hand, when the flexible polymer is introduced as the toughening agent, the flexible polymer is limited by thermodynamic incompatibility between a molecular structure and a rigid polyester matrix, and phase separation is easy to occur in the system, so that the interface binding force is insufficient, the toughening efficiency is weakened, and the original transparency and degradability of the material can be damaged. Meanwhile, most of the existing toughening systems mainly pay attention to mechanical property improvement, have limited effect of improving flowability and adhesiveness of materials in the melt processing process, and are difficult to meet industrial processing requirements of high efficiency and low energy consumption. Bottle brush polymers are a class of comb-like polymeric materials with highly dense grafts of side chains to the backbone, whose molecular conformation exhibits a spatial unfolding characteristic that is significantly different from that of linear or block polymers. The molecular size, the conformational rigidity and flexibility and the viscoelastic behavior of the polymer can be adjusted in a larger range by adjusting and controlling the main chain composition, the side chain chemical structure and the grafting density. Studies have shown that bottle brush polymers exhibit potential application value [ ACS Macro Lett., 2012, 1 (9): 1146-1149] in the fields of elastomers, soft matter regulation and nanostructure construction, etc., due to their large repulsive volume, low entanglement characteristics, and unique rheological properties. In theory, the densely distributed flexible side chains in the bottle brush polymer are expected to form a multi-scale physical interpenetrating structure with the polymer matrix in the blending system, thereby improving interface compatibility and promoting stress transmission and energy dissipation. However, the prior studies have focused on the field of non-degradable systems or functional materials [ macromol. Rapid Commun. 2025, 46, 2500215], bottle brush polymer systems for rigid biodegradable polyester toughening applications have not been reported yet. In addition, the main stream synthesis method of the existing bottle brush polymer generally depends on a metal catalyzed grafting through polymerization or controllable free radical polymerization strategy, has harsh requirements on the reaction environment, has high synthesis cost and insufficient degradability, and limits the practical application of the bottle brush polymer in the field of environment-friendly materials. In view of the above, the prior art has not yet lacked a toughening solution which is simple to prepare, has strong structural designability, can achieve high-efficiency toughening in rigid biodegradable polyester, and has processability and simultaneously has degradab