RX-971 Bromianted SBS

Chemical Name: Brominated butadiene/styrene block copolymer

Alternative Name: Brominated styrene butadiene styrene block copolymer

Brand Name: RX-971

Equivalent Grade: Emerald Innovation 3000，FR-122P

CAS NO.: 1195978-93-8

Chemical Structure:

Application:

RX-971 is s a highly effective, sustainable brominated polymeric flame retardant offering a variety of enhanced performance properties. This innovative flame retardant is an excellent replacement for Hexabromocyclododecane (HBCD) in both expanded polystyrene (EPS) and extruded polystyrene (XPS) foam products.

 

Technical Data Sheet

 

Packing：

RX-971 is packed in 20kg paper bag,20bags on pallet.Total 8MT per 20’FCL

Advantages of Brominated SBS Replacing HBCD in Applying EPS and XPS as Exterior Wall Insulation Materials

The comprehensive prohibition of HBCD both domestically and internationally has made it a new hot topic for researchers to search for alternatives to HBCD and put them into production. Through the demonstration and performance testing organized by experts from the China Flame retardancy Society, as well as the trial use and certification issued by relevant manufacturers, it has been verified that brominated SBS can not only be used as a broad-spectrum flame retardant, but also a perfect substitute for HBCD. The various performance requirements of HBCD substitutes can be perfectly matched with brominated SBS. In terms of environment, health, and safety, brominated SBS has low toxicity and is not classified as a persistent organic pollutant (POP) or toxic (PBT) substance; In terms of flame retardant performance, it is similar to HBCD and meets the regulations of flame retardant standards worldwide (such as the European Union, the United States, Canada, etc.); In terms of foam characteristics, it can effectively maintain the physical characteristics of EPS and XPS foam; In terms of production process, meet the requirements for EPS and XPS stability; Economically adaptable in terms of cost, it can achieve industrial production, and its mechanical properties are improved compared to HBCD.

As a high-quality flame retardant specifically designed to reduce the harm of existing flame retardants, brominated SBS has undergone rigorous environmental, health, and safety assessments and testing, and the results show that this flame retardant has extremely low environmental hazards, toxicity to organisms, and bioaccumulation. Compared with HBCD, its unique macromolecular properties prevent brominated SBS from penetrating the cell membrane and entering the organism. At present, the technology of brominated SBS has been commercialized, laying the foundation for the sustainable development of brominated SBS. Research has shown that products containing brominated SBS have effectively maintained people's expectations for external wall insulation materials in the market, meeting market requirements in density, compressive strength, fire resistance, water absorption performance, flexural strength, thermal stability, and zero VOC emissions. They can be widely used in buildings such as walls, roofs, underground, and cold storage. Nowadays, many companies have commercialized the use of brominated SBS. The FUDAXPSeco insulation board containing brominated SBS produced by Guangzhou Fuda Insulation Materials Co., Ltd. has successfully passed the China B1 combustion performance grading test.

Since the development and promotion of alternative flame retardant brominated SBS, more and more researchers have devoted themselves to the study of brominated SBS. Wang Liangmin et al. proposed a method for preparing brominated SBS products with narrow molecular weight distribution and high thermal stability. This method involves multiple steps such as mixing, dissolving, and reacting TBAB and Br2 with a molar weight of 1:1 to prepare a low-cost brominated SBS. This preparation method is not only cheap and stable in raw material price, but also simple in process, Greatly improving the purity of brominated SBS, while reducing the high polymer content in its copolymer, it also improves the mechanical properties of brominated SBS. Guo Anpeng et al. proposed multiple production processes for the preparation of brominated SBS, with the first one being the direct bromination method, which is a relatively mild reaction process. This method improves the preparation amount and thermal stability of brominated SBS. Subsequently, a one-step production process for preparing brominated SBS was proposed, which further improved the thermal stability of brominated SBS and greatly improved production efficiency due to its one-step production process. In 2022, a method for preparing brominated SBS with high thermal decomposition temperature was proposed. This method only uses one catalyst and can be reused multiple times, thereby saving costs. The organic solvent used in the process is dichloromethane, which can also be distilled and recycled for reuse. Guo Anpeng et al. not only studied and explored the preparation methods of brominated SBS, but also continuously improved the preparation machinery. In 2020, a refining system for preparing brominated SBS was disclosed. By recombining various parts of the bromination kettle and using a series of post-treatment processes to refine the centrifugal separator, water washing kettle, crystallization kettle, decolorization kettle, filtration device, and dryer inside the bromination kettle, the purity and quality of brominated SBS products were improved.

With the improvement of people's environmental awareness, all substances that pose a threat to the ecological environment will not be accepted by people. Therefore, it is necessary and necessary to replace HBCD with environmentally friendly flame retardants. Brominated SBS, regardless of its physical properties, production process, and specific applications, fully conforms to the international definition and understanding of green environmental protection and energy conservation. With the development of China's industry and the pursuit of energy conservation and environmental protection, The development of new environmentally friendly flame retardants such as brominated SBS will also usher in a new future.

Prodcution Process:

A synthesis method for high thermal stability Brominated SBS, comprising the following steps:

(1) Dissolve SBS in an organic solvent, add it to a 50% hydrogen peroxide solution, add a catalyst, raise the temperature to 35-60 ℃, add 48% hydrobromic acid dropwise, keep it warm for 2-6 hours after dropwise addition, cool it to room temperature, and let it stand still for layering;

(2) Add peroxides and alkali metal alkoxides to the organic layer in the lower layer after layering, raise the temperature to 35-60 ℃, keep it warm for 1-2 hours to remove impurities, then wash the organic layer with water and dry it with calcium chloride solid;

(3) Add the dried organic layer to the composite catalyst, dropwise add an organic solution containing bromine chloride at a temperature of 5 ℃ -8 ℃, keep it warm at a temperature of 15-20 ℃, then neutralize free bromine with an alkaline substance, distill under the action of water and emulsifier to remove the solvent, and filter and dry to obtain Brominated SBS product.

The organic solvent used for dissolving SBS in step (1) and the organic solvent used for the organic solution containing bromine chloride in step (3) are either one or more of dichloroethane, chloroform, carbon tetrachloride, or toluene. The mass ratio of the organic solvent to SBS is 10-1:1, and the mass ratio of bromine chloride to the organic solvent is 1:1-10

The mass ratio of hydrobromic acid to hydrogen peroxide solution in step (1) is 4.8-6:1, and the mass ratio of hydrobromic acid to SBS is 2:1.

The catalyst in step (1) consists of a phase transfer catalyst and a methyl bromide inhibitor. The phase transfer catalyst is one or more of tetraethylammonium bromide, tetrabutylammonium bromide, and benzyltriethylammonium chloride. The dosage of the phase transfer catalyst is 1wt% -10wt% of the SBS, and the methyl bromide inhibitor is any one or two of tin tetrachloride and titanium tetrachloride, The dosage of the methyl bromide inhibitor is 0.1wt% -1wt% of the SBS.

The peroxide in step (2) is hydrogen peroxide, and the alkali metal alkoxide is sodium methoxide. The dosage of both hydrogen peroxide and alkali metal alkoxide is 1wt% -5wt% of the SBS.

The composite catalyst in step (3) is composed of a metal chloride and iodine, and the metal chloride is any one or more of titanium tetrachloride, tin tetrachloride, iron trichloride, and antimony trichloride. The mass ratio of the metal chloride to the amount of iodine is 3:1, and the total amount of the composite catalyst is 2wt% -5wt% of the SBS.

The mass ratio of bromine chloride to SBS in step (3) is 1.5-2:1.

The alkaline substance in step (3) is any one or more of sodium thiosulfate, sodium hydroxide, sodium methoxide, sodium ethanol, sodium sulfite, hydrazine hydrate, or ammonia water

The emulsifier in step (3) is any one or more of 2% -5% aqueous solutions of hydroxyethyl cellulose or polyvinyl alcohol.

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