A silane-modified esterified polyether and its preparation method and application

Abstract

The present invention provides a silane-modified esterified polyether and a preparation method and application thereof. The preparation method of the silane-modified esterified polyether comprises the following steps: S1, reacting single-end allyl polypropylene glycol with trimethoxyhydrogen-containing silane under the protection of an organic acid to obtain a single-end alkoxy-terminated silane-modified polyether through a hydrosilylation reaction; S2, reacting the single-end alkoxy-terminated silane-modified polyether obtained in S1 with an ester compound through a dealcoholization chain extension reaction to obtain a silane-modified esterified polyether; wherein the ester compound contains at least two ester groups. The present invention innovatively uses dibasic esters and polybasic esters in combination with other raw materials to achieve the purpose of polyether chain extension through a simple dealcoholization reaction. The preparation method provided by the present invention can successfully synthesize a silane-modified esterified polyether that can be used to prepare a sealant without introducing an acid-binding agent.

Description

Technical Field

[0001] The invention relates to the technical field of synthesis of silane-modified polyether polymers, and more specifically to a silane-modified esterified polyether and a preparation method and application thereof. Background Art

[0002] Silane-modified polyether sealants are prepared with polyether polyols as raw materials. The molecular weight of polyether polyols on the domestic market is concentrated between 400 and 4000. Polyether polyols with a molecular weight greater than 8000 are difficult to prepare. As a result, in order to obtain high molecular weight polyethers, it is usually necessary to use low molecular weight polyether polyols to extend the chain in order to meet the requirements of polyether sealants for base rubber molecular weight, strength and other properties during application.

[0003] In the prior art, the commonly used chain extender is dichloromethane. After -OM is formed using alkali metal alcohol salts or sodium / potassium hydroxide, MCl is removed with dichloromethane to achieve the chain extension effect. This method has a darker color of the silane-modified polyether due to the introduction of alkaline substances, and MCl is difficult to be completely removed in the polyether chain system, resulting in a high chloride ion content in the silane-modified polyether and a deviation in the quality of the polyether. Summary of the invention

[0004] In order to solve the shortcomings of the current macromolecular silane-modified polyether chain extension technology, a silane-modified esterified polyether and a preparation method thereof are proposed. The preparation method can be applied to allyl-terminated polyethers of all molecular weights, and the raw materials are easily available and have high industrial feasibility.

[0005] The preparation method of the silane-modified esterified polyether provided by the present invention comprises the following steps:

[0006] S1, reacting single-end allyl polypropylene glycol with trimethoxy hydrosilane under the protection of an organic acid to obtain a single-end alkoxy-terminated silane-modified polyether;

[0007] S2, preparing a silane-modified esterified polyether by subjecting the single-end alkoxy-terminated silane-modified polyether obtained in S1 to a dealcoholization chain extension reaction with an ester compound;

[0008] Wherein, the ester compound contains at least two ester groups.

[0009] In a preferred embodiment of the present invention, in step S1, the organic acid is acetic acid, oxalic acid or citric acid, preferably acetic acid. In step S1, the pH of the reaction system is adjusted to 2-5.

[0010] In a preferred embodiment of the present invention, the molecular weight of the polypropylene glycol in the single-end allyl polypropylene glycol (A-PPG-OH) can be 200, 400, 600 or 1000, preferably 800.

[0011] In a preferred embodiment of the present invention, in the step S1, the molar ratio of the single-end allyl polypropylene glycol to trimethoxy hydrogen-containing silane is 1:(1-1.1), preferably 1:(1.02-1.05).

[0012] In a preferred embodiment of the present invention, in step S1, the catalyst in the hydrosilation reaction is a Speier catalyst, wherein the amount of the Speier catalyst used is such that the amount of Pt in the reaction system is 5 to 100 ppm, preferably 10 to 40 ppm.

[0013] In a preferred embodiment of the present invention, the specific steps of step S1 include: mixing single-end allyl polypropylene glycol, an organic acid and a catalyst for hydrosilylation reaction, activating at 20 to 60° C. for 0.5 to 2 hours, adding trimethoxyhydrogen-containing silane, and keeping warm for 2 to 10 hours. When the iodine value in the system is not higher than 0.5, removing impurities to obtain a single-end alkoxy-terminated silane-modified polyether.

[0014] In a preferred embodiment of the present invention, in step S2, the ester compound is dimethyl terephthalate, dimethyl phthalate or 2,4-toluenedicarbamate, preferably dimethyl phthalate.

[0015] Wherein, in the step S2, the molar ratio of the single-end allyl polypropylene glycol in S1 to the ester compound in S2 is 1:(0.5-0.8), preferably 1:(0.55-0.62). The reaction temperature of the dealcoholization chain extension reaction is preferably 60-180°C, and the reaction time is preferably 2-10h. In a preferred embodiment, the reaction temperature is preferably 80-140°C, and the reaction time is preferably 3-6h. In step S2, the solvent used is a non-protonic polar solvent such as DMF, THF, preferably DMF, and the amount of the solvent is based on the sufficient mixing of the raw materials. In the embodiment of the present invention, the amount is about 50-100mL. When it is necessary to expand production, the amount of solvent is increased accordingly.

[0016] Another object of the present invention is to provide a silane-modified esterified polyether prepared by the above preparation method.

[0017] Another object of the present invention is to provide the above preparation method or the use of the obtained silane-modified esterified polyether in the preparation of sealants.

[0018] The beneficial effects of the present invention are:

[0019] (1) The present invention innovatively uses dibasic esters and polybasic esters in combination with other raw materials to achieve the purpose of polyether chain extension through a simple dealcoholization reaction, and can be chain extended multiple times to prepare polyethers with a molecular weight of more than 18,000. The silane-modified esterified polyether prepared by the present invention has very excellent tensile strength and elongation at break, and can be used in sealants.

[0020] (2) The preparation method provided by the present invention can successfully synthesize the silane-modified esterified polyether that can be used to prepare the sealant without introducing an acid-binding agent. In the entire reaction, no salt by-product is produced, and the produced alcohol has high purity and can be recycled as a raw material for the synthesis of trimethoxyhydrogen-containing silane. DETAILED DESCRIPTION

[0021] The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0022] Example 1

[0023] The embodiment of the present invention provides a method for esterifying polyether modified by silane, comprising the following steps:

[0024] (1) Preparation of single-end alkoxy-terminated silane-modified polyether (TM1)

[0025] 100gA-PPG800-OH and 0.6g acetic acid were added, the pH of the whole system was adjusted to 3.52, Speier catalyst was added (wherein, the amount of Speier catalyst added was such that the content of Pt in the whole reaction system relative to the mixed raw materials was 12ppm), the reaction was activated at 35°C for 0.5h, 14.79g trimethoxyhydrogen-containing silane was added dropwise, the reaction was kept warm for 3h, the iodine value was measured to be 0.32, the unreacted methoxyhydrogen-containing silane and the by-product tetramethoxysilane were recovered by distillation at elevated temperature and reduced pressure to obtain a nearly colorless methoxy-terminated polyether.

[0026] (2) Preparation of silane-modified esterified polyether (TM2)

[0027] The methoxy-terminated polyether obtained in (1) was mixed with 100 mL of THF and 12.71 g of dimethyl phthalate and heated at 80°C for reaction for 5 h until a slight reflux of alcohol occurred. The distillation apparatus was changed to raise the temperature to 120°C while collecting methanol, and the methanol was recovered. The temperature was raised and the pressure was reduced to recover THF and unreacted methyl phthalate, to obtain 114.55 g of silane-modified esterified polyether TM2.

[0028] Example 2

[0029] The embodiment of the present invention provides a method for esterifying polyether modified by silane, comprising the following steps:

[0030] (1) Preparation of single-end alkoxy-terminated silane-modified polyether (TM1)

[0031] 100gA-PPG1000-OH and 0.6g oxalic acid were added, the pH of the whole system was adjusted to 2.34, Speier catalyst was added (wherein, the amount of Speier catalyst added was such that the content of Pt in the whole reaction system relative to the mixed raw materials was 12ppm), the reaction was activated at 35°C for 0.5h, 11.93g trimethoxyhydrogen-containing silane was added dropwise, the reaction was kept warm for 3h, the iodine value was measured to be 0.43, the unreacted methoxyhydrogen-containing silane and the by-product tetramethoxysilane were recovered by distillation at elevated temperature and reduced pressure to obtain a nearly colorless methoxy-terminated polyether.

[0032] (2) Preparation of silane-modified esterified polyether (TM2)

[0033] The methoxy-terminated polyether obtained in (1) was mixed with 100 mL DMF and 10.25 g dimethyl terephthalate and heated at 80° C. for reaction for 5 h until a slight reflux of alcohol occurred. The distillation apparatus was changed to raise the temperature to 120° C. while collecting methanol to recover methanol. The temperature was raised and the reduced pressure was reduced to recover THF and unreacted dimethyl terephthalate to obtain 102.51 g of silane-modified esterified polyether TM2.

[0034] Example 3

[0035] The embodiment of the present invention provides a method for esterifying polyether modified by silane, comprising the following steps:

[0036] (1) Preparation of single-end alkoxy-terminated silane-modified polyether (TM1)

[0037] Acetic acid was added to 100 g of A-PPG800-OH, the pH of the whole system was adjusted to 5, Speier catalyst was added (wherein, the amount of Speier catalyst added was such that the content of Pt in the whole reaction system relative to the mixed raw materials was 35 ppm), the reaction was activated at 25 ° C for 1 hour, 15.27 g of trimethoxyhydrogen-containing silane was added dropwise, the reaction was kept warm for 4 hours, the iodine value was measured to be 0.41, the temperature was increased and the reduced pressure distillation was performed to recover the unreacted methoxyhydrogen-containing silane and the by-product tetramethoxysilane, and a nearly colorless methoxy-terminated polyether was obtained.

[0038] (2) Preparation of silane-modified esterified polyether (TM2)

[0039] The methoxy-terminated polyether obtained in (1) was mixed with 100 mL DMF and 14.33 g dimethyl phthalate and heated to 100° C. for reaction for 3 h. The distillation apparatus was changed to raise the temperature to 120° C. while collecting methanol, and the methanol was recovered. The temperature was raised and the pressure was reduced to recover DMF and unreacted methyl phthalate, to obtain 114.06 g of silane-modified esterified polyether TM2.

[0040] Example 4

[0041] The embodiment of the present invention provides a method for esterifying polyether modified by silane, comprising the following steps:

[0042] (1) Preparation of single-end alkoxy-terminated silane-modified polyether (TM1)

[0043] Acetic acid was added to 100 g of A-PPG800-OH to adjust the pH of the whole system to 3.52, and a Speier catalyst was added (wherein, the amount of Speier catalyst added was such that the content of Pt in the whole reaction system relative to the mixed raw materials was 5 ppm) to activate the reaction at 60°C for 0.5 h, and 14.54 g of trimethoxyhydrogen-containing silane was added dropwise. The reaction was kept warm for 1 h, and the iodine value was measured to be 0.36. The unreacted methoxyhydrogen-containing silane and the by-product tetramethoxysilane were recovered by distillation at increased temperature and reduced pressure to obtain a nearly colorless methoxy-terminated polyether.

[0044] (2) Preparation of silane-modified esterified polyether (TM2)

[0045] The methoxy-terminated polyether obtained in (1) was mixed with 100 mL of THF and 11.55 g of dimethyl phthalate and heated at 60°C for reaction for 10 h until a slight reflux of alcohol occurred. The distillation apparatus was changed to collect methanol while raising the temperature to 120°C to recover the methanol. The temperature was then raised and the pressure was reduced to recover THF and unreacted dimethyl phthalate to obtain 105.55 g of silane-modified esterified polyether TM2.

[0046] Example 5

[0047] The embodiment of the present invention provides a method for esterifying polyether modified by silane, comprising the following steps:

[0048] (1) Preparation of single-end alkoxy-terminated silane-modified polyether (TM1)

[0049] Acetic acid was added to 100 g of A-PPG800-OH to adjust the pH of the whole system to 3.52, and a Speier catalyst was added (wherein, the amount of Speier catalyst added was such that the content of Pt in the whole reaction system relative to the mixed raw materials was 100 ppm) to activate the reaction at 20°C for 2 h, and 16.00 g of trimethoxyhydrogen-containing silane was added dropwise, and the reaction was kept warm for 2 h. The iodine value was measured to be 0.39, and the unreacted methoxyhydrogen-containing silane and the by-product tetramethoxysilane were recovered by distillation at increased temperature and reduced pressure to obtain a nearly colorless methoxy-terminated polyether.

[0050] (2) Preparation of silane-modified esterified polyether (TM2)

[0051] The methoxy-terminated polyether obtained in (1) was mixed with 100 mL DMF and 18.49 g dimethyl phthalate and heated at 150° C. for reaction for 2 h until a slight reflux of alcohol occurred. The methanol was recovered by changing the distillation apparatus. The DMF and unreacted dimethyl phthalate were recovered by increasing the temperature and reducing the pressure to obtain 105.29 g of silane-modified esterified polyether TM2.

[0052] Experimental example

[0053] The silane-modified esterified polyethers provided in the examples and comparative examples of the present invention were used to prepare sealants for performance testing.

[0054] The preparation method of the sealant is as follows: 100 parts by mass of silane-modified esterified polyether, 200 parts by mass of active light calcium carbonate, 60 parts by mass of carbon black (active light calcium carbonate and carbon black are dried at 120°C to remove water for 24 hours in advance), 80 parts by mass of polypropylene glycol plasticizer, and 3 parts by mass of vinyltrimethoxysilane are mixed and stirred evenly, 1 part by mass of salicylate absorbent and 1 part by mass of 2,6-butyl-4-methylphenol are added thereto, stirred until uniformly dispersed, 1 part by mass of dibutyltin dilaurate is added, and stirred evenly to obtain the sealant.

[0055] The sealant prepared by the above method using the silane-modified esterified polyether provided in the examples and comparative examples was tested, wherein the tensile strength and elongation at break were tested according to GB / T528-2009, and the test results are shown in Table 1 below.

[0056] Table 1 Performance results

[0057]

[0058]

[0059] Finally, the method of the present invention is only a preferred embodiment and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a silane-modified esterified polyether, characterized in that: The steps include: S1, mixing single-end allyl polypropylene glycol, organic acid and a catalyst for hydrosilylation reaction, activating at 20-60°C for 0.5-2h, adding trimethoxy hydrosilane, keeping warm for 2-10h, and removing impurities when the iodine value in the system is not higher than 0.5 to obtain a single-end alkoxy-terminated silane-modified polyether; The organic acid is acetic acid, oxalic acid or citric acid; The molar ratio of the single-end allyl polypropylene glycol to trimethoxy hydrosilane is 1: (1-1.1); The catalyst for the hydrosilation reaction is a Speier catalyst; the amount of the Speier catalyst is such that the amount of Pt in the reaction system is 5 to 100 ppm; the pH of the reaction system in step S1 is 2 to 5; The molecular weight of the polypropylene glycol in the single-end allyl polypropylene glycol is 400 to 1000; S2, preparing a silane-modified esterified polyether by a dealcoholization chain extension reaction of the single-end alkoxy-terminated silane-modified polyether obtained in S1 with an ester compound in the presence of a solvent; the solvent is DMF or THF; Wherein, the ester compound is dimethyl terephthalate or dimethyl phthalate; The molar ratio of the single-end allyl polypropylene glycol to the ester compound is 1:(0.5-0.8); The reaction temperature of the dealcoholization chain extension reaction is 60-180° C., and the reaction time is 2-10 hours.

2. The preparation method according to claim 1, characterized in that: In the step S1, the organic acid is acetic acid.

3. The preparation method according to claim 1 or 2, characterized in that: In the step S1, the molecular weight of the polypropylene glycol in the single-end allyl polypropylene glycol is 800.

4. The preparation method according to claim 1 or 2, characterized in that: In the step S1, the molar ratio of the single-end allyl polypropylene glycol to trimethoxy hydrogen-containing silane is 1:(1.02-1.05).

5. The preparation method according to claim 1 or 2, characterized in that: In the step S1, the catalyst in the hydrosilation reaction is a Speier catalyst, wherein the Pt content is 10-40 ppm.

6. The preparation method according to claim 1 or 2, characterized in that: In the step S2, the ester compound is dimethyl phthalate.

7. The preparation method according to claim 1 or 2, characterized in that: In the step S2, the molar ratio of the single-end allyl polypropylene glycol to the ester compound is 1:(0.55-0.62).

8. The preparation method according to claim 1 or 2, characterized in that: In the step S2, the solvent is DMF.

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