TDI polyurethane prepolymers have excellent mechanical performance and chemical resistance in various applications.

TDI polyurethane prepolymers are formed by partially reacting TDI with different types of polyols (such as polyester or polyether polyols), resulting in a product with a certain amount of free isocyanate (NCO) content. This allows further cross-linking or reactions during subsequent processing. TDI prepolymers are usually in liquid or viscous form, and their specific physical properties depend on the NCO content and the type of polyol used.

Characteristics

1. High Reactivity : The isocyanate groups in TDI polyurethane prepolymer can react with water, alcohols, and other chemicals to form a polyurethane network.
2. Excellent Wear Resistance and Elasticity : TDI polyurethane prepolymer has outstanding wear resistance, tear strength, and elasticity, making it suitable for demanding mechanical applications.
3. Adjustable Hardness : By adjusting the NCO content in the prepolymer and the type of polyol reacted, the final product's hardness and other mechanical properties can be tailored.
4. Chemical Resistance : TDI polyurethane prepolymer exhibits good resistance to oils, fuels, and various chemicals.

Properties

NO.	1	2	3	4	5	6	7	8	9	10	11
Type	Polyester/TDI system					Polyether/TDI system			PTMEG/TDI system
Model	BQ8341	BQ8026	BQ8315	BQ8035	BQ8317	BQ8308	BQ8311	BQ8306	BQ8319	BQ8235	1260
NCO content %	2.1±0.2	2.6±0.2	3.0±0.2	3.5±0.2	5.0±0.2	4.5±0.2	6.5±0.2	3.0±0.2	3.0±0.2	3.5±0.2	6.0±0.2
State of matter at 20°C	White Soild	White Soild	White Soild	White Soild	White Soild	Colorless transparent liquid	Colorless transparent liquid	Colorless transparent liquid	White waxy solid	White waxy solid	white waxy solid
Hardener	MOCA	MOCA	MOCA	MOCA	MOCA	MOCA	MOCA	MOCA	MOCA	MOCA	MOCA
100g prepolymer curing agent dosage (g)	6.2	7.7	8.8	10.3	14.8	13.3	19.2	8.8	8.8	10.3	17.7
Prepolymer/curing agent mixing temperature (°C)	85/120	85/120	85/120	80/120	80/120	80/120	75/120	80/120	80/120	80/120	75/120
Viscosity at 85°C (mpa·s)	3000	2600	2000	1600	1100	350	270	350	1200	800	500
Gel time (min)	13-18	13-17	12-16	10-15	6-10	12	8	6-10	12-17	11-15	7-10
Post curing time (100℃/h)	16	16	16	16	16	16	16	16	16	16	16
Hardness (Shore A)	70±2	75±2	80±2	87±2	94±2	85±2	95±2	73±2	80±2	85±2	95±2
Tensile strength (mpa)	42	43	45	46	47	25	35	8	28	32	45
100% modulus stress (mpa)	2.5	3.5	3.7	4.1	8	6	10	2	5	6	11
300% modulus stress (mpa)	4	5.5	7	8	16	10	16	5	8	10	23
Elongation at break (%)	850	720	680	660	500	500	380	650	580	550	400
Right Angle Tear Strength (kN/m)	50	58	72	80	105	60	95	45	63	70	110
Pants tear strength (kN/m)	18	22	32	40	46	18	25	12	20	25	35
Rebound (%)	43	40	38	35	32	27	22	48	55	50	43
Density at 25°C (g/cm3)	1.2	1.23	1.25	1.25	1.25	1.1	1.18	1.08	1.08	1.1	1.13
DIN wear (mm3)	50	48	45	43	45	120	110	130	45	44	44

Application

TDI polyurethane prepolymers are widely used in many industrial fields:

1. Elastomers: TDI prepolymers are often used in the production of polyurethane elastomers, such as industrial rollers, conveyor belts, and shock absorbers, where high wear resistance and strong mechanical properties are required.

2. Coatings and Adhesives: TDI polyurethane prepolymers are commonly used as a base material in industrial coatings and adhesives, particularly in areas requiring chemical resistance and wear resistance. They are suitable for coating and bonding metals, wood, plastics, and other materials.

3. Sealants: TDI prepolymers are frequently used in polyurethane sealant formulations, ideal for applications in construction, automotive, and other fields where weather resistance and sealing properties are critical.

4. Footwear Materials: Due to its wear resistance and elasticity, TDI prepolymers are often used in shoe sole materials, especially in high-performance athletic shoes.

5. Foams: While MDI (Methylene Diphenyl Diisocyanate) prepolymers are more commonly used in flexible foam materials, TDI prepolymers are also utilized in producing some high-density foam products, particularly in certain rigid foam applications.