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CN-122011317-A - Polyacetal-siloxane copolymer with wide emission band and preparation method thereof

CN122011317ACN 122011317 ACN122011317 ACN 122011317ACN-122011317-A

Abstract

The invention discloses a wide-emission band polyacetal-siloxane copolymer and a preparation method thereof, belonging to the technical field of polymer synthesis, wherein the copolymer is prepared by taking hydroxyalkyl siloxane containing hetero atoms (such as O, S, N and the like) and aldehyde compounds as raw materials through polycondensation reaction under the action of a catalyst. The preparation process has mild condition, simple operation and high selectivity. The acetal oxygen atoms in the obtained copolymer are aggregated to form oxygen clusters, the flexible Si-O-Si chain segments promote molecular aggregation, and the synergistic effect of the coordination of S-Si enables the copolymer to show excellent atypical fluorescence performance, and the fluorescence emission spectrum can cover And exhibits a red-shift characteristic depending on the excitation wavelength, and achieves broadband emission from blue light to near infrared light. The invention breaks through the technical bottleneck that the wave band of the organic silicon atypical fluorescent material is limited to the blue light region, and has wide application prospect in various fields.

Inventors

  • WANG DENGXU
  • HUAN YU
  • FENG SHENGYU

Assignees

  • 山东大学

Dates

Publication Date
20260512
Application Date
20260324

Claims (10)

  1. 1. The broad emission band polyacetal-siloxane copolymer is characterized in that the structural formula of the broad emission band polyacetal-siloxane copolymer is shown as formula I: I is a kind of In the formula I, m is an integer greater than or equal to 2, and n is an integer greater than or equal to 0; 、 、 、 Can be selected from A linear or branched saturated or unsaturated hydrocarbon group, or a hydrocarbon group having O, S, N heteroatoms, or a cycloalkane or arene, 、 、 R4 are the same or different; 、 Selected from the group consisting of Is a linear chain saturated hydrocarbon group of (a), 、 X is selected from O, N, S and other heteroatoms; selected from straight-chain or branched-chain saturated hydrocarbon groups, aromatic hydrocarbon or aromatic hydrocarbon with substituent groups.
  2. 2. A broad emission band polyacetal-siloxane copolymer according to claim 1, wherein the internal network of the broad emission band polyacetal-siloxane copolymer comprises an acetal structure, and a segment containing an X heteroatom and a flexible Si-O-Si segment.
  3. 3. A method for preparing the broad emission band polyacetal-siloxane copolymer according to claim 1, comprising the steps of: Adding hydroxyalkyl siloxane containing hetero atoms, aldehyde compounds and a catalyst into a reactor together, stirring and reacting at 20-180 ℃, and separating and purifying to obtain the wide-emission-band polyacetal-siloxane copolymer; The structural formula of the heteroatom-containing hydroxyalkyl-terminated siloxane is shown as a formula II; II (II) In the formula II, n is an integer greater than or equal to 0; 、 、 、 Can be selected from A linear or branched saturated or unsaturated hydrocarbon group, or a hydrocarbon group having O, S, N heteroatoms, or a cycloalkane or arene, 、 、 、 The same or different; 、 Selected from the group consisting of Is a linear chain saturated hydrocarbon group of (a), 、 And X is selected from O, N, S and other hetero atoms.
  4. 4. The method for producing a broad emission band polyacetal-siloxane copolymer according to claim 3, wherein the hydroxyalkyl siloxane having a hetero atom contains a hydroxyl group, the aldehyde compound contains an aldehyde group, and the molar ratio of the hydroxyl group to the aldehyde group is 1 (1 to 4).
  5. 5. The method for preparing a broad emission band polyacetal-siloxane copolymer according to claim 3, wherein the hydroxyalkyl siloxane containing hetero atoms is selected from one of the group consisting of but not limited to bis [3- (dihydroxyethylamino) propyl ] blocked polysiloxane, bis [3- (hydroxyethoxy) propyl ] blocked polysiloxane, bis [2- (hydroxyethylthio) ethyl ] tetramethyldisiloxane, bis [3- (hydroxyethylthio) propyl ] tetramethyldisiloxane, and bis [ (hydroxyethylthio) methyl ] tetramethyldisiloxane.
  6. 6. The method for preparing a wide emission band polyacetal-siloxane copolymer according to claim 3, wherein the aldehyde compound is a monoaldehyde compound containing one aldehyde group, and the monoaldehyde compound is an aldehyde substrate selected from aliphatic aldehyde, aromatic aldehyde or hetero atom type; The aliphatic aldehyde has a carbon chain length of ; The aldehyde group of the aromatic aldehyde is directly or indirectly connected with an aromatic ring, and the aromatic ring is unsubstituted or is halogen, Alkyl group, At least one substituent selected from the group consisting of alkoxy, nitro, cyano, hydroxy, mercapto and amino; the aldehyde substrate of the heteroatom type comprises, in addition to the aldehyde group, at least one heteroatom selected from oxygen, nitrogen, sulphur, phosphorus or halogen.
  7. 7. The method for preparing a broad emission band polyacetal-siloxane copolymer according to claim 3, wherein the catalyst is selected from the group consisting of a protonic acid and a Lewis acid; the heteroatom-containing hydroxyalkyl siloxane contains hydroxyl groups, and the catalyst is used in an amount of 0.01% -20% of the molar amount of the hydroxyl groups.
  8. 8. The method for producing a broad emission band polyacetal-siloxane copolymer according to claim 3, wherein the stirring reaction is not limited to being carried out in an organic solvent, the organic solvent is an organic basic solvent, and the ratio of the hydroxyl-containing siloxane having a hetero atom to the organic basic solvent is 1g (1 to 5) mL.
  9. 9. The method for preparing a broad emission band polyacetal-siloxane copolymer according to claim 3, wherein the reaction temperature of the stirring reaction is 60 to 180℃and the reaction time is 12 to 48 hours.
  10. 10. The broad emission band polyacetal-siloxane copolymer according to claim 1, wherein the fluorescence emission spectrum measured under the fluorescence spectrophotometer covers a wavelength range of 400nm to 700nm after the broad emission band polyacetal-siloxane copolymer is prepared into a methylene chloride solution with a concentration of 0.1-10 mg/mL; as the excitation wavelength increases, the emission wavelength of the broad emission band polyacetal-siloxane copolymer exhibits an excitation wavelength-dependent red-shift characteristic.

Description

Polyacetal-siloxane copolymer with wide emission band and preparation method thereof Technical Field The invention relates to the technical field of polymer synthesis, in particular to a polyacetal-siloxane copolymer with a wide emission band and a preparation method thereof. Background The siloxane material has excellent properties of high and low temperature resistance, weather resistance, aging resistance, good insulativity, good biocompatibility and the like, and has wide application in the fields of aerospace, electronic devices, chemical industry, construction, medicine and the like. The hydroxyl terminated siloxane has reactivity, can be used for modifying other polymers, and endows polysiloxane with excellent performance. At present, hydroxyalkyl siloxane is limited by modification of organic polymers such as polyester, polyurethane and the like, the modified material is poor in degradability and recoverability, and the modified material is easy to accumulate for a long time after being abandoned to cause environmental pollution. There is therefore an urgent need to develop new siloxane-based materials, expanding the application scene. At present, the emission wavelength of the organic silicon material with atypical fluorescence performance is mainly concentrated in a blue light region, and cannot meet the requirements of deep tissue optical treatment and biological imaging in the biomedical field and the requirements of photoelectric devices on multicolor display, which greatly limit the practical application of the organic silicon material. Therefore, development of an organosilicon atypical material with a long wavelength (such as red light or even near infrared light) light-emitting band, breaking through the limitation of traditional blue light emission, is a key challenge for realizing wide application of the organosilicon atypical material. In the prior art, CN116693858 discloses a preparation method of an atypical fluorescent material of hydroxyalkyl polysiloxane, which takes the hydroxyalkyl polysiloxane and unsaturated olefin as raw materials, and the functionalized polysiloxane with atypical high fluorescence intensity is prepared through nucleophilic addition reaction between hydroxyl and double bonds under the action of a catalyst, but the prepared functionalized polysiloxane emits light to be concentrated in a blue light region. CN119798676 discloses a preparation method of functional polysiloxane with blue-green atypical fluorescence, epoxy polysiloxane and furanyl-containing compound are adopted as raw materials, and through mercapto-epoxy click reaction, the furanyl polysiloxane with beta-hydroxyl is prepared, while the light-emitting band is expanded to blue-green light, the red shift range of the emission wavelength along with the excitation wavelength is limited (< 100 nm), and red light and near infrared light-emitting bands are not involved. However, research on realizing significant red shift of a siloxane-based atypical fluorescent material by introducing an acetal bond and a heteroatom coordinate bond through polycondensation reaction has not been reported systematically at present. Therefore, development of atypical fluorescent materials based on siloxane groups is urgently needed to break through the limitation of the emission band of the existing materials, widen the emission band to longer bands (such as red light and even near infrared light), and expand the application scenes of the atypical fluorescent materials in the biomedical fields such as photoelectric device multicolor display systems and phototherapy and imaging of deep tissues. Disclosure of Invention The invention provides a preparation method of a polyacetal-siloxane copolymer with a wide emission band, which aims to overcome the defects that the emission band of the traditional siloxane-based atypical fluorescent material is narrow and the near infrared is difficult to cover. The invention takes heteroatom-containing hydroxyalkyl siloxane and aldehyde compound as raw materials, and the copolymer is prepared by polycondensation reaction under the condition of an acidic catalyst and temperature. The acetal oxygen atoms are aggregated to form oxygen clusters, and the Si-O-Si flexible chain segments promote the molecular aggregation and the synergistic effect of the coordination effect of X-Si (X is O, S and the like) to realize the coverage of an emission spectrum(Blue light-near infrared) and excitation wavelength dependent red shift (. Gtoreq.150 nm). The method is simple and convenient to operate and high in selectivity, breaks through the limitation of the light-emitting wave band of the existing material, and has application potential in the fields of fluorescence sensing and biological imaging. According to the invention, the method preferably comprises the steps of: Adding hydroxyalkyl siloxane containing hetero atoms, aldehyde compounds and a catalyst into a reactor together, stirring and reacting for