Hydroxyethyl methacrylate (HEMA) is a non-toxic, harmless, and widely used reagent, commonly used for soft lens materials, lens materials, or as a monomer for preparing dense ceramics and glass. Polyhydroxyethyl methacrylate (PHEMA) is a promising biopolymer with significant inertness, biocompatibility, and insolubility. Method 1: Place 100 ml of toluene, 62.1 (1 mol) parts of ethylene glycol, and enzymes (Novozym 435, 0.04 parts, 0.01 parts of sodium carbonate, and 0.01 parts of hydroquinone manufactured by Novo) into a 1-liter glass flask connected to a cooling tube receiver (for measuring moisture) and a reflux side tube, and heat to 40 ° C. 72.1 parts (1mol) of acrylic acid were added in batches within 10 minutes, while stirring step by step. After completing the total addition, the mixture was stirred at the same temperature under reduced pressure of 10mPa. After the reaction, the target acrylate was obtained by filtering and separating the catalyst and additives. The time required for the reaction is approximately 6 hours. The yield and composition of the obtained acrylate were determined by gas chromatography (hereinafter abbreviated as GC). [0044] [Example 2] [0045] Except for changing 72.1 parts (1 mol) of acrylic acid to 86.1 parts (1 mol) of methacrylic acid in Example 1, the target compound was obtained in a similar manner to Example 1. The time required for the reaction is approximately 5 hours. The yield of hydroxyethyl methacrylate (HEMA) was 98.5% by gas chromatography. The synthesis is continuous as shown in Figure 1. Method 2: Add 31.05g ethylene glycol (EG, 0.5mol), 47.35g (0.55mol) methacrylic acid, 40g (inside, 22g water in the catalyst before use, 18g dry weight) strong acid ion exchange resin (Amberlite IR124: gel type, 12% cross-linking degree, no pore), 0.086g HO-TEMPO, 0.086g hydroquinone and 200g toluene into a 500ml glass flask equipped with Dean Stark device, cooling pipe, thermometer and air inlet pipe, Then heat and stir at 100 ℃, while using a pump to add water at a rate of 2g/h. The water formed in the reaction is azeotropic with toluene and removed through the Dean Stark device. After 5 hours, the conversion rate of hydroxyethyl methacrylate was 87.3%. The synthesis is continuous as shown in Figure 1. purpose Hydroxyethyl methacrylate is mainly used for modifying resins and coatings. Copolymerization with other acrylic monomers can produce acrylic resins with active hydroxyl groups in the side chains, which can undergo esterification and crosslinking reactions, synthesize insoluble resins, improve adhesion, and can be used as fiber treatment agents. It reacts with melamine formaldehyde (or urea formaldehyde) resin, epoxy resin, etc. to manufacture two component coatings. Adding it to high-end car paint can maintain the mirror gloss for a long time. It can also be used as an adhesive for synthetic textiles and as a medical polymer monomer

Product Name：prothioconazole CAS NO. 178928-70-6 Payment:T/T Min order:1000kg Lead time:7-15 days

Name: Silicon(IV) Chloride CAS No.: 10026-04-7 Appearance: Colorless transparent liquid Molecular weight: 169.9 Relative density: 1.483 Purity: ≥ 99.0% Flash point: No data available Boiling point: 57 ℃ Melting point: -70 ℃ Refractive index nD20:1.412

Name: 1,1,1,3-Tetrachloropropane CAS No.: 1070-78-6 Molecular formula: CCl3CH2CH2Cl Molecular weight: 182 Physical property constant: b. p.159 ℃ Appearance: Colorless or light yellow transparent liquid Purity: ≥ 99% Packaging: 250 kg/barrel Moisture content: ≤ 0.1%

Introduction:  Hexamethyldisiloxane (silicone ether, MM sealing agent) is a colorless and transparent liquid that is prone to deliquescence. Insoluble in water, soluble in various organic solvents. Used as silicone oil, silicone rubber, pharmaceuticals, gas chromatography stationary liquids, analytical reagents, hydrophobic agents, etc. Obtained by hydrolysis of trimethylchlorosilane.  The physical properties of hexamethyldisiloxane  colorless and transparent liquids. Easily deliquescent, flammable, and in contact with high heat, open flames, and strong oxidizing agents, there is a risk of combustion. Boiling point 99.5 ℃. Flash point -1.1 ℃. Relative density (d2525) 0.7606. The refractive index is 1.3750. Insoluble in water, soluble in various organic solvents.  Hexamethyldisiloxane is an important primary organic silicon raw material, often used as a capping agent in the production of silicone oil, or as a cleaning agent for silicone rubber, pharmaceuticals, gas chromatography stationary liquids, analytical reagents, hydrophobic agents, and medical electronic components. The Si O-Si bond in the molecular chain structure of hexamethyldisiloxane has a high chemical bond energy (460 5 kJ/mol), the polysiloxane prepared from it as a sealing agent has good thermal and chemical stability.

Name: Chlorotrimethylsilane CAS number: 75-77-4 Molecular formula: C3H9ClSi Molecular weight: 108.64 EINECS number: 200-900-5 Mol file: 75-77-4.mol

Name: Sodium bis (trimethylsilyl) amide CAS number: 1070-89-9 Molecular formula: C6H18NNaSi2 Molecular weight: 183.37 EINECS number: 213 983-8 Mol file: 1070-89-9.mol

Name: paracetamol CAS No.: 103-90-2 Appearance: Colorless crystalline powder Molecular formula: C8H9NO2 Molecular Weight: 151.163 Melting point:168°C-172℃  PACKAGE:25KGS/BAG

Name: Cefuroxime axetil CAS No.: 64544-07-6 Appearance: White to light yellow powder Molecular formula: C20H22N4O10S Molecular Weight: 510.474 Melting point:175-180 °C PACKAGE:25KG/DRUM

Name: Lysine Hcl CAS No.: 10098-89-2 Appearance: White crystalline or crystalline powder Molecular formula: C6H15ClN2O2 Molecular Weight: 182.648 Melting point:263℃-264 °C Stardands：CP2020 PACKAGE:25KG/BAG

Name: DL-Pantolactone CAS No.: 79-50-5 Appearance: White needle  Molecular formula: C6H10O3 Molecular Weight: 132.1343 Melting point:74-78 °C(lit.) PACKAGE:35KG/drum

Name: Zinc Pyrithione CAS No.: 13463-41-7 Appearance: Grayish white to yellowish brown powder Molecular formula: C10H8N2O2S2Zn Molecular Weight: 317.722 Melting point:262ºC PACKAGE:25KG/BAG