1, The full name of polyurethane is "polyurethane", usually refers to isocyanate (MDI, TDI, PMDI...) With hydroxyl compounds containing active hydrogen, such as small polyols (ethylene glycol, butanediol, glycerol, diethanolamine, triethanolamine... , and macromolecular polyether polyols, polyester polyols, polycondensation reaction under catalyst and/or thermal excitation conditions, to produce linear and/or cross-linked polymer with carbamate as the characteristic chain segment;

2, And isocyanate isocyanate base group (-NCO) and hydroxyl group containing active hydrogen (-OH) will occur condensation reaction to generate carbamate chain segment, because the typical isocyanate-NCO group conjugated double bond structure -N=C=O in the C atom electron cloud density is low, Therefore, it tends to react with hydroxyl (-OH) and amine (-NH2) compounds with high electron cloud density.

3, Alkali metal catalyst, and organic tin catalyst is the principle of the metal ion can and isocyanate - NCO group coordination and makes the - NCO group polarization, so that the isocyanate with positive electrical carbon atoms in the molecule is more lively, more vulnerable to containing active hydrogen compounds (- OH, -nh2) group, nucleophilic attack caused by nucleophilic reaction to generate carbamic acid ester;

3-1 In general, the weak acid salts of potassium and sodium elements in the alkali metal group, such as potassium acetate (KAC), potassium isoctanoate (K-15), potassium oleate, sodium methanol, and the weak acid salts of tin, lead, mercury and bismuth in non-ferrous metals, such as stannous octanoate (T-9), dibutyltin diloctanoate (T-12), tin mercaptocarboxylate (T-120) lead isoctanoate. Mercuric acetate, bismuth isoctanoate and bismuth naphthenate (MB-20) can catalyze the polycondensation reaction between isocyanate-NCO and hydroxy-OH groups to form carbamate.

3-2 Specifically pointed out that potassium acetate and potassium isoctanoate are stronger for the trimerization of isocyanate catalysis, potassium isoctanoate is the strongest trimerization catalyst.

The non-ferrous metal catalysts such as tin and bismuth catalysts are the strongest gel catalysts, which strongly catalyze the polymerization of carbamate;

3-4 Lead and mercury group catalysts are highly efficient and insensitive to water reaction. They were widely used in polyurethane coating, adhesives, and elastomer industries in the past, but have been banned due to heavy metal toxicity.

4. The principle of tertiary ammonia catalyst is that when the three H atoms of NH3 are replaced by the electron group and the alkyl group with larger steric hindrance, the electron cloud density on the N atom will increase and the alkalinity will be improved. The isocyanate has the ability to form an unstable complex with the electropositive isocyanate of the C atom, leading to the continuous nucleophilic reaction.

4-1,Polyurethane elastomers, adhesives, coatings, fibers and other non-foaming applications mainly use tin group, bismuth group metal catalysts to avoid the tertiary ammonia catalyst caused by isocyanate base group (-NCO) and water vapor bubbling reaction between the quality of products;

4-2, Applied in the field of polyurethane rigid foam catalyst choice surface is very wide: N 'n-dimethylcyclohexylamine (DMCHA, PC-8), pentamethyldiethylenetriamine (PMDETA, PC-5), double - (dimethyl aminoethyl) ether (DMAEE, A-1) are promoting isocyanate and water to produce carbon dioxide foaming catalyst;

4-2-1, And triethylene diamine (DETDA, A-33), N, N-dimethylcyclohexylamine (DMCHA, PC-8) is also A typical foaming/gel balance catalyst, the former A-33 heavy gel, the latter DMCHA heavy foaming, both together with A-1 and KAC is the choice of the hard foam insulation industry basis;

4-2-2. In the actual application of polyurethane, the isocyanate (-NCO) reaction group of rigid polyurethane is usually designed to be isocyanate, which is slightly excessive compared with the active hydrohydroxyl group and amine group (-OH, -NH2), so that the excess -NCO group continues to react with the H atom of the secondary amine on the link segment of carbamate. The synthesis of urea-formate ester makes polyurethane resin stronger; And more excess isocyanate (-NCO) will be in the trimerization catalyst (alkali metal weak acid salts: potassium acetate (KAC), potassium isoctanoate (K-15); Ammonia catalyst: three - (dimethyl amino) phenol (DMP-30), double - (dimethyl amino propyl) hexahydrotriazine (PC-41) under the action of trimerization reaction to generate highly cross-linked isocyanurate structure, making polyurethane resin harder, more brittle, more thermal stability.

Another tertiary ammonia catalyst N 'N-dimethylbenzylamine (BDMA) has a unique application in the rigid polyurethane foam industry. It can promote the surface maturation of the rigid foam system with high water content, improve the fragility of the skin, and improve the adhesion between the foam body and other substrates.

4-3, Polyurethane soft foam applications, double - (dimethyl aminoethyl) ether (DMAEE, A-1) and triethylene diamine (DETDA, A-33) has been the standard catalyst combination: With A-1 as the main catalyst, A-33 as the auxiliary, catalyze the inspired foaming reaction between isocyanate and water, and then A-33 as the main catalyst to promote polyurethane gel, maturation reaction, the catalytic process is stable and efficient. However, the volatile and unpleasant odor characteristics of these two typical tertiary ammonia catalysts increasingly limit their application in the field of soft foam home and automotive interior decoration.

4-4. A new generation of high boiling point macromolecular tertiary amine catalysts, as well as reactive catalysts embedded with reactive hydroxyl (-OH) groups and secondary amine groups (-NH-) have emerged in the field of home and automobile interior parts with strict requirements for odor /VOC volatilization: Low odor gel reaction catalyst N, n-bis (3-dimethylaminopropyl) -N-diisopropyl amine, can replace the typical equilibrium catalyst A-33 foaming/gel balance reaction catalyst N- (dimethylaminopropyl) diisopropyl amine (Jeffcat DPA) and tetramethyldipropyl triamine (Jeffcat Z-130), N 'n-dimethyl-1, 3-malenediamine (DMAPA)

5, For the application of polyurethane foam, foaming reaction is very important. Isocyanate reacts with water to form carbon dioxide, which is the basic foaming reaction. At the same time, it exothermic and generates urea, and the urea group will continue to react with isocyanate to form biurea. This series of reactions for soft, high rebound and semi-hard polyurethane foam, in addition to the formation of gas bubble network, rigid biuret bond also plays a role in improving the hardness of soft foam.

For the foaming reaction of rigid polyurethane foam, in addition to the reaction of isocyanate and water to generate carbon dioxide foaming, there will be additional physical foaming agent, early dichloromethane, chlorofluorocarbons (F-11), hydrochlorofluorocarbons (H-141b), hydrofluorocarbons (HFC-365mfc), HFC-245fa, The aforementioned physical blowing agents have been phased out or are being phased out over the past 30 years due to the greenhouse effect and ozone layer depletion effect, and the current mainstream pentane blowing agents (cyclopentane, isopentane, n-pentane). The main characteristics of this kind of physical foaming agent are low boiling point, non-toxic, low thermal conductivity, and the formation of bubble structure under the action of polyurethane chemical reaction heat gasification;

6, Silicone surfactant commonly known as silicone oil, it is through the siloxane - propylene oxide - ethylene oxide copolymerization formed with oil hydrophilic characteristics of the surface force regulation of a polymer. The siloxane chain segment reduces polarity between different substances and promotes night fusion; The cyclopropyl chain segment on the branch chain of organosilicon surfactant has hydrophilic, cycloethyl chain segment has hydrophilic, can promote the water-borne polyether polyol and oily isocyanate in the external shear force (mechanical agitation, high pressure impact mixing) under the action of easy to fully emulsified and form a macroscopic phase stable emulsion, In this way, the bubble seeds produced by the foaming reaction are stable and nucleated and expanded to become regular bubble pores. The higher the proportion of cyclo-B chain, the stronger the hydrophilicity, the higher the tendency of foam opening, which is mostly used in soft polyurethane foam; The higher the proportion of cyclopropyl chain segment, the stronger the lipophilicity, the higher the tendency of foam closure, which is mostly used for thermal insulation of rigid polyurethane foam;


Wuhan Zhongpeng Chemical Technology Co., Ltd. is located in Wuhan Chemical Industry Park, the only national chemical industry park in Wuhan, covering an area of 100 mu. The company has a long history. It originated from Wuhan United Petrochemical Co., Ltd. established in 1978. It is the only comprehensive service provider in Central China that integrates the R & D, production and sales of high-performance water reducer with an annual output of 260000 tons and polyether with an annual output of 100000 tons.

Polycarboxylic water reducing agent series products are necessary building materials for various concrete construction projects. The company ranks among the top three in China and the first in Central China. It has won dozens of honors such as "national famous trademark", "China's green building products", "the most influential brand in China's concrete admixture industry", and passed the ISO quality management system and CRCC product certification.

Polyether series products are the main raw materials of polycarboxylic acid high-performance water reducer, which are widely used in coatings, rubber resins, plastics, building materials and other fields.

With the new pace of the construction of the national Yangtze River economic belt, the company plans a cross regional, diversified and "one China, two wings" business strategy. With Wuhan as the group headquarters, the company wholly controls more than 10 subsidiaries in Hainan, Xiangyang, Xiaogan, etc., seizes the opportunity, deeply cultivates the Hubei Free Trade Zone, radiates the Hainan free trade port and the ASEAN Free Trade Zone, resonates with the same frequency, strives to forge ahead, and cooperates with customers, partners and other sectors of society with a more open mind, Join hands to create a win-win situation and participate in the grand event!

Our company pass ISO9001:2008 QS certificate,GB/T19001-2008 quality management.We know well of technical inspection, marketing, transportation...And we will give you 100% support anytime in any way.


Q1. What is your terms of payment?
A: T/T 30% as deposit, and 70% before delivery. We'll show you the photos of the products and packages
before you pay the balance.

Q2. What is your terms of delivery?
A: EXW, FOB, CFR, CIF, DDU.

Q3. How about your delivery time?
A: Most of our products have stock,But, it will take 7 to 15 days after receiving your advance payment. The specific delivery time dependson the items and the quantity of your order.

Q4. Can you produce according to the samples?
A: Yes, we can produce by your samples or detailed requirement.

Q5. What is your sample policy?
A: We can supply the sample for testing, but the customers have to pay the sample cost and
the courier cost.

Q6. Do you test all your goods before delivery?
A: Yes, we have 100% test before delivery

Q7: How do you make our business long-term and good relationship?
1. We keep good quality and competitive price to ensure our customers benefit ;
2. We respect every customer as our friend and we sincerely do business and make friends with them, no matter where they come from.


Pls feel free to contact us at Anytime:
Ms. Emma Peng