CN-121975129-A - Linear nitrogen-sulfur-containing polyborosiloxane and preparation method and application thereof

CN121975129ACN 121975129 ACN121975129 ACN 121975129ACN-121975129-A

Abstract

The invention discloses linear nitrogen-sulfur-containing polyborosiloxane and a preparation method and application thereof. The technical scheme innovatively adopts a two-step method to accurately regulate and control the polymerization process, namely, firstly, constructing a functional flame-retardant unit through the directional reaction of boric acid and phenyl sulfonic acid compound with amino, then, using the functional flame-retardant unit as an active intermediate to polymerize with hydroxyl-terminated silicone oil, realizing the controllable growth of a molecular chain, and finally, preparing the linear nitrogen-sulfur-containing polyborosiloxane. The nitrogen-sulfur-containing polyborosiloxane prepared by the invention only needs to be added in an amount of 0.2-0.4wt%, has the excellent effects of promoting PC to form charcoal and resisting molten drops, ensures that the polycarbonate composite material has good thermal stability and high carbon residue, passes the UL-94 V0 level test and the S2 needle flame test, and simultaneously maintains excellent impact resistance.

Inventors

PENG LI
DAI JINFENG
JIANG BAIYU
XIE DAN
WANG DAN

Assignees

长三角物理研究中心有限公司
深圳华烯创科技有限公司
中国科学院物理研究所

Dates

Publication Date: 20260505
Application Date: 20260212

Claims (10)

1. A linear nitrogen-sulfur-containing polyborosiloxane is characterized in that a molecular main chain is formed by alternately copolymerizing x siloxane units and boron units, wherein the repeating structural units are (-Si (R1) (R2) -O-B (-R3) -O-) X , the siloxane units are provided with substituent groups R1 and R2, the boron units are-B (OH) 3 -, wherein R1 and R2 are independently selected from benzene rings, methyl, ethyl or vinyl, x is greater than 5, two hydroxyl groups of the boron units are respectively dehydrated and condensed with hydroxyl groups of the siloxane units, a boron atom in the main chain is connected with a silicon-oxygen bond by a-B (O-) bond to form a Si-O-B covalent bond, R3 is (MSO 3 -Ph-NH-or MSO 3 -NH-), the metal ion M is K + 、Na + 、Li + , and Ph is a benzene ring structure.
2. The linear nitrogen-sulfur containing polyborosiloxane according to claim 1, wherein the number average molecular weight M n is (5 x10 3 ～8×10 4 ).
3. A method for preparing linear nitrogen-sulfur-containing polyborosiloxane according to claim 1, which is characterized by comprising the following steps of (1) carrying out solid-phase polycondensation reaction on boric acid compounds and sulfamate under the conditions of 150-200 ℃ and-0.1-0.05 MPa to obtain an intermediate, wherein the molar ratio of hydroxyl groups of the boric acid compounds to amino groups of the sulfamic acid compounds is 1:0.1-1; (2) And cooling the intermediate to 80-120 ℃, adding hydroxyl-terminated silicone oil and a catalyst, and performing polycondensation reaction to obtain the linear nitrogen-sulfur-containing polyborosiloxane, wherein the molar ratio of the hydroxyl groups of the hydroxyl-terminated silicone oil to the hydroxyl groups of the boric acid compound is 1:0.3-1.5.
4. The method according to claim 3, wherein the boric acid compound in the step 1 is boric acid, and the aminophenylsulfonic acid compound is one or more of potassium sulfanilic acid, sodium sulfanilic acid, lithium sulfanilic acid, potassium 3, 4-diaminobenzenesulfonate, sodium 3, 4-diaminobenzenesulfonate, potassium 2, 5-diaminobenzenesulfonate and sodium 2, 4-diaminobenzenesulfonate.
5. The method according to claim 3, wherein the molecular weight of the hydroxyl-terminated silicone oil in the step 2 is 500-20000, the substituent is benzene ring or methyl or ethyl or vinyl or a combination of four, and the catalyst is concentrated sulfuric acid, phosphoric acid containing 5 to 20 phosphoric acid units or a mixture thereof.
6. The method according to claim 3, wherein the sulfamic acid compound in step 1 is added to the boric acid compound by dropping at a dropping speed of 1-5 mL/min.
7. The method according to claim 3, wherein the reaction time of the polycondensation reaction in step 2 is 0.5 to 4 hours.
8. The use of the linear nitrogen-sulfur-containing polyborosiloxane according to claim 1 as a flame retardant, wherein the nitrogen-sulfur-containing polyborosiloxane is prepared by heating, melting and blending the linear nitrogen-sulfur-containing polyborosiloxane with polycarbonate, and then hot-press molding the mixture to obtain a polycarbonate composite material, wherein the content of the nitrogen-sulfur-containing polyborosiloxane in the polycarbonate composite material is 0.2-1.0wt%.
9. The method according to claim 8, wherein the heating and melting blending is performed by a torque rheometer, the processing temperature is 260 ℃, the processing time is 8-15 minutes, the rotating speed is 50 r/min, the hot press forming is performed by a flat vulcanizing machine, the hot press temperature is 260 ℃, and the pressure is 10MPa.
10. The use according to claim 8, wherein the polycarbonate composite has a UL-94 vertical fire rating of V-0.

Description

Linear nitrogen-sulfur-containing polyborosiloxane and preparation method and application thereof Technical Field The invention belongs to the technical field of flame retardants, and particularly relates to linear nitrogen-sulfur-containing polyborosiloxane, and a preparation method and application thereof. Background The Polycarbonate (PC) shows certain flame retardant property (LOI is 24 percent and reaches V-2 grade) in the UL-94 vertical burning test, but with the improvement of fire safety requirements, the problems of flammability, serious dripping during burning, large smoke release amount and the like greatly limit the application in high-end fields such as aerospace, electronics and the like, so the development of the high-performance flame retardant PC material has important significance and broad prospect. The PC releases a large amount of CO 2, phenol derivatives and ether gases in the combustion process, and the melt viscosity of the PC is low, so that the pure PC has insufficient carbon forming capability in the combustion process, and the PC has a molten drop phenomenon and cannot self-quench. The polycarbonate flame retardant commonly used at present comprises halogen series, silicon series, boron series, sulfonate series, phosphorus series and the like. The halogen flame retardant has good flame retardant effect, can achieve better flame retardant property with relatively small addition amount, and can effectively reduce the combustion speed and flame propagation of the material. But release a large amount of toxic gases and smoke during combustion, which is not friendly to the environment and human health, and is gradually prohibited at present. The sulfonate flame retardant has the greatest advantages of high flame retardant efficiency and small addition amount, and can basically maintain the mechanical strength and other properties of the polycarbonate substrate while improving the flame retardant property. However, when the flame retardant is used alone, the flame retardant efficiency of the flame retardant cannot completely meet the requirement of a PC thin-wall part for realizing UL-94V-0 grade or the phenomenon of molten drops exists, and the flame retardant is usually required to be compounded with other flame retardants for use. Moreover, the conventional sulfonate flame retardant is easy to precipitate in PC base materials due to low molecular weight, so that the durability of the material is poor. In addition, the silicon flame retardant has the characteristics of no halogen, no phosphorus, no smoke and no toxicity, is easy to migrate to the surface of the material at high temperature, forms a-Si-O-or-Si-C-structure, plays roles in heat insulation and flame retardance, can adsorb smoke and toxic gas in the combustion process, has the characteristics of environmental protection flame retardant, and is widely favored by industry. However, the organic silicon is also generally required to be compounded to achieve a synergistic flame-retardant effect, the flame-retardant efficiency is limited when the organic silicon is used alone, and the addition amount is required to be increased to achieve the flame-retardant effect. And the addition amount is increased, so that the cost is increased, and the mechanical property of the material is easily deteriorated. While boron compounds promote char formation, they tend to migrate and have poor dispersibility. The flame retardant can not realize high-efficiency flame retardance of polycarbonate when being added independently in a small amount, and more important problems are that PC molten drop phenomenon still exists during combustion, and the flame retardant is often required to be compounded with the anti-molten drop agent, so that flame retardance and anti-molten drop effect are realized. The research shows that if Si-O-B copolymerization skeletons can be simultaneously introduced into the same polymer molecule, and the polarity and the compatibility are regulated through the nitrogenous sulfonate groups, the balance of efficient synergistic flame retardance and thermal stability can be expected to be realized. Therefore, the development of the nitrogen-sulfur-containing polyborosiloxane flame retardant with definite structure, controllable molecular weight and good processing compatibility has important significance. Disclosure of Invention Aiming at the technical bottlenecks that the flame retardant in the prior art has poor flame retardant effect and is difficult to solve the problem of molten drops in compounding, the invention provides linear nitrogen-sulfur-containing polyborosiloxane, and a preparation method and application thereof. The technical scheme innovatively adopts a two-step method to accurately regulate and control the polymerization process, namely, firstly, constructing a functional flame-retardant unit through the directional reaction of boric acid and phenyl sulfonic acid compound with amino, then, using the function