Polyurethane raw materials

Diafor Company is the manufacturer of MDI and TDI based polyurethane raw materials for elastomers. All the components for elastomers production by means of hot casting are developed and manufactured according to the requirements of individual client. Great experience in compounding, technology and application of different additives as well as in different process methods – all these offer exciting opportunities for ready-to-use elastomers based on PUR. An experienced staff of Diafor Company provides a continuous technical backup concerning the use of components of raw polyurethane materials. Diafor Company produces polyesters DIATEK (see Table 1 for main properties). Polyesters production is based on adypic acid and different glycols. Polyesters are used as feedstock for MDI and TDI prepolymers production.

Table 1

Polyesters DIATEK

Grade	Polyester composition	% - OH,	Molecular weigh	Acid-value, mgKOH/g	Viscosity, 75 ºС cps
5359	E glycol / 1.4 BD / Adypic acid	70-77	1500	>0.5	400-500
5458	E glycol / 1.4 BD / Adypic acid	54-58	2000	>0.5	500-800
3541	E glycol / 1.4 BD / Adypic acid	35-41	3000	>0.5	1300-1700
2531	E glycol / 1.4 BD / Adypic acid	25-31	4000	>0.5

MDI and TDI prepolymers production is based on use of polyesters (see Table 2 and 3 for main properties)

Table 2

Prepolymers DIAFOR based on TDI polyesters

Grade	NCO , %	Shelf life, min	Hardness
5055	5 ± 5.5	3	90 ± 3
4548	4.5 ± 4.8	6	85 ± 2
3035	3.0 ± 3.5	8	75 ± 2

Table 3

Prepolymers DIAFOR based on MDI polyesters

Grade	NCO, %
DIAFOR 4050- MDI	4.0-5.0
DIAFOR 7080- MDI	7.0-8.0
DIAFOR 1011- MDI	10-11

Diafor Company is also producing prepolymers based on polyethers PTMEG (see Table 4, 5 and 6 for main properties)

Table 4

Prepolymers DIAFOR based on polyethers PTMEG TDI

Grade	NCO , %	Shelf life, min	Max. Hardness
83А	3 ± 0.3	15	83 ± 3
90А	4.2 ± 0.3	12	90 ± 3
93А	5.2 ± 0.3	10	93 ± 3
95А	6.25 ± 0.2	4-5	95 ± 3

Prepolymers DIAFOR of high hardness based on polyethers PTMEG TDI

Table 5

Grade	NCO , %	Shelf life, min	Max. Hardness
60D	7.5 ± 0.2	3	60 ± 3
70D	9.2 ± 0.2	1-2	73 ± 3
85D	12 ± 0.2	1.5	84 ± 3

Prepolymers DIAFOR based on polyethers PTMEG MDI

Table 6

Grade	NCO , %	Shelf life, min	Max. Hardness
75А	4.0 ± 0.2	10-11	75 ± 2
85А	6.9 ± 0.2	6	85 ± 2
95А	8.5 ± 0.2	3	95 ± 2

Diafor Company is also producing quasi-prepolymers MDI (see Table 7 for main properties)

Table 7

QUASI-POLYMER SYSTEMS:

Quasi-prepolymers DIAFOR		Quasi-prepolymers DIAFOR
Grade	NCO, %	Grade	NCO, %
DIAFOR QUASI 1417- MDI	14-17	DIAFOR QUASI 2427- MDI	24-27

THE COMPONENTS FOR PRODUCTION OF PUR-BASED ELASTOMERS WITHOUT FOLLOWING THERMAL TREATMENT Quasi-prepolymers are the products based on diisocyanates and polyols having NCO end groups. They contain NCO-groups in the range of 16-27%. These products are liquids under room temperatures. They are suitable for PUR-elastomers production by one-shot method. These quasi-prepolymers are processed with polyols and glycol crosslinkers. Processing temperature depends on the melting point of polyols and is about 50-80 °C, which is significantly lower than prepolymers systems have. In this case, we don’t need an additional thermal treatment which is necessary for prepolymers systems. Such elastomers are characterized by high strength and wear resistance. Quasi-prepolymers were specially developed for well-disposed production by technology simplification. The advantages of quasi-prepolymers over traditional hot-casting systems: • Liquid components already under room temperature • Decreased components ratio in the mixture • Decreased processing temperatures • Lack of additional thermal treatment

SYSTEM DIATEK QUASI-MDI FOR PROCESSING under 80 °C

DIATEK 5458 MDI	Mass ratio.	100	100	100	100	100
DIATEK processing temperature	° С	80	80	80	80	80
1,4-BUTANEDIOL	Mass ratio.	2.0	3.5	5.8	8.5	14.2
Catalyzed	Mass ratio.	2.0	1.5	1.2	1.0	0.8
Temperature 1,4-BD	° С	23	23	23	23	23
DIAFOR QUASI 2427 MDI	Mass ratio.	29.75	33.5	41.0	50.5	71.0
DIAFOR QUASI 2427 MDI temperature	° С	23	23	23	23	23
Casting mold temperature	° С	110	110	110	110	110
Mold exposure	мин	25	25	20	18	10
Tempering	° С/h	no	no	no	no	no

PHYSICAL PROPERTIES

Shore А/D hardness		65/-	75/-	82/-	87/34	93/45
100% tension stress, mPa	mPa	2.5	3.3	4.5	6.6	11
300% tension stress, mPa	mPa	5.0	7.5	11	19	25
Tensile at break, mPa	mPa	25	42	42	42	40
Breaking elongation, %	%	475	440	440	410	375
Tear strength of cut sample (Graves)	kN/m	10	15	20	30	55
Rebound, %	%	68	55	53	50	41
Erosion	mm³	25	25	25	25	30

Compounding and properties of DIATEK TDI system based on polyesters

DIAFOR 4548 TDI	Mass ratio.	100	100	100
DIAFOR processing temperature	° С	90	90	70
Crosslinking agent		MOCA	DIBUTEK Т	DIBUTEK М
Crosslinking agent temperature	° С	110	90	25
Cast time	min	18	8	3
Casting mold temperature	° С	110	110	110
Mold exposure	min	15	13	3
Tempering	° С/h	24/110	24/110	24/110

PHYSICAL PROPERTIES

		MOCA	DIBUTEK Т	DIBUTEK М
Shore А/D hardness	mPa	87/32	85/30	85/30
100% tension stress, mPa	mPa	5.9	4.9	5.8
300% tension stress, mPa	mPa	8.4	8.2	7.8
Tensile at break, mPa	mPa	57	44	56
Breaking elongation, %	%	594	580	578
Tear strength of cut sample (Graves)		41	26	38
Rebound, %	%	39	47	53
Erosion		52	55	36