## 3 Material Preparation
### Selection and Preparation of Modifiers
It is a soluble solid that is white or yellowish, flaky or powdery, hard to volatilize, and, when dissolved in water, it forms a transparent solution [14]. It is chemically stable to alkalis, dilute acids, and hard water, and is slightly toxic. In applications, SDBS has excellent detergency. It has significant decontamination effect on particulate dirt, protein dirt and oily dirt, especially on the washing effect of particulate dirt on natural fibers. Its detergency increases with the increase of washing temperature, its effect on protein dirt is higher than that of nonionic surfactants, and it has rich foam. Experimentally, SDBS was prepared using three propylene zwitterionization method. First, propylene undergoes a zwitterionic reaction in the presence of a catalyst to produce tetrap polypropylene. Then, the tetrap polypropylene is subjected to an alkylation reaction with benzene to introduce alkyl side chains to produce an alkylated product. In the third step, the alkylated product is subjected to a sulfonation reaction to introduce sulfonic acid groups to produce a sulfonated product. Finally, the sulfonated product is neutralized with a suitable base to generate SDBS. Through this synthetic method, highly branched SDBS can be obtained, and this compound has excellent surface activity and emulsifying properties. The chemistry of the preparation of SDBS is shown in Figure 3.  
The preparation of TPS (trisulfated melamine formaldehyde resin) involves two key steps: the condensation reaction of melamine and formaldehyde and the sulfation process. Initially, melamine and formaldehyde react under appropriate conditions to produce melamine formaldehyde resin (MF resin). Subsequently, the sulfonic acid group can be introduced through the sulfation reaction using different sulfation agents. When using concentrated sulfuric acid as a sulfonation agent, the sulfuric acid molecules react with the amino or amino groups in the resin to form sulfonic acid groups. It is important to control the temperature and stirring conditions to prevent side reactions, such as resin degradation or crosslinking. If smoked sulfuric acid is used as a sulfonation agent, its highly reactive SO3 molecules quickly react with amino or amino groups in the resin to form a sulfonic acid group. However, this may also cause excessive oxidation, leading to carbonization due to the strong oxidation and dehydration of smoked sulfuric acid. Additionally, using SO3 as a  
Figure 2: Schematic diagram of the preparation process for Sipan 40.  
sulfonation agent is a viable method. SO\({}_{3}\) reacts directly with the amino or imino group in the resin to form a sulfonic acid group. However, it is crucial to control the amount of SO\({}_{3}\) and the reaction temperature precisely to prevent undesired side reactions, such as cross-linking or resin degradation. The chemical components utilized in TPS preparation pose potential hazards. Long-term exposure or inhalation of melamine dust can have adverse effects on health, such as respiratory tract irritation and skin sensitivity. Additionally, it may decompose and produce harmful gases under high temperatures. Formaldehyde has a strong irritant effect on the human body, and long-term exposure may increase the risk of cancer. Concentrated sulfuric acid and fuming sulfuric acid are highly corrosive and oxidizing. Contact with the skin and eyes can cause serious burns, while inhaling vapors can seriously damage the respiratory tract. Additionally, sulfur trioxide is highly irritating and toxic. During the preparation process, it is essential to strictly adhere to safety operating procedures, wear appropriate protective equipment, carry out the process in a closed and well-ventilated environment, and be prepared to handle potential chemical accidents. Particular attention should be paid to the treatment of waste and exhaust gases to prevent harm to the environment and personnel.