TomLong Techstile Corp.

Tear Strength

Tear strength is the term which defines the resistance of a notched test specimen ( TPU Elastomers ) to tear propagation. Tear strength is generally regarded as the critical indication of the physical strength to external force. In this respect, TPU is superior to most of other plastics.

Properties	TPU		PVC		NBR	CR	NR
Hardness Shore A	96	90	94	87	78	70	77
Tear Strength (kN/m)
Right Angle Cut	129	80	70	70	37	36	65
Line Cut	137	63	38	48	19	25	40

Abrasion Resistance

TPU can withstand a lot of physical abuse including scratch, friction, corrosion forced upon the surface of the materials. With over three times the durability of rubber, TPU provides excellent abrasion resistance, functioning well across a broad range of end-applications. (Taber Method， Load 1000g，23℃,5000Times)

TPU	Rubber		Nylon		PVC		PE		Other Plastic
Abrasion (mg)	Item	Abrasion (mg)	Item	Abrasion (mg)	Item	Abrasion (mg)	Item	Abrasion (mg)	Item	Abrasion (mg)
0.5 ~ 3.5	SBR	177	NYLON6	366	General	160	HDPE	29	PS	324
	NBR	205	NYLON66	49	Soft Grade	187	LDPE	70	PBS	545
	CR	280	NYLON610	16	Hi-Strength	122			PET	18
	NR	146	NYLON11	24					ABS	275

Hydrolysis Resistance

At normal temperatures, TPU exhibits outstanding resistance to hydrolysis for 1-2 years without undergoing any changes (decomposition) while its mechanical properties are still maintained. In particular, TPU Ether grade demonstrates superior hydrolysis resistance to Ester grade. If Polyester based TPU series is exposed for six months to hot water at 50℃ ( or at 70℃ for three weeks, or 100℃ for 3 to 4 days ), an irreversible break down of the Polyester chains will occur through hydrolysis ( decomposed ) ; and as the consequences, the mechanical properties of the film will deteriorate. In this respect, TPU is regarded as environmentally friendly materials. For end applications that constant contact with water is inevitable, TPU Ether grade is certainly the ideal candidate to be taken into consideration.

Resistance to oil, chemicals and greases

The excellent resistance to greases and pure mineral oils (such as lubricating, fuel, and diesel oils) provided by TPU make them well suited for many industrial and food contact applications. TPU does not react chemically to the oil contamination and usually results in higher tensile strength than the initial properties detected. While the response of other plastics materials to oil contamination appears to be poor, TPU has once again proved to be superior to other plastics materials. However, in the case of contamination of water identified in mineral oils, the reduction in TPU physical properties is inevitable.

Properties

ASTM No.1 oil

ASTM No.3 oil

TPU

NBR

TPU

NBR

Hardness

Tensile Strength ﹪

Elongation ﹪

Volume

+5.5

+15.5

-0.5

+15

+20.1

-21.5

-3.8

-2

-10.2

-13.2

+1.5

-1

-6.5

-6.8

+3.7

-6

-5.6

-17.6

-12.7

-20

-27.3

-33.3

+56.2

Heat Resistance and Ageing (Weather Durability)

Plastics are chemically degraded by the effect of UV-radiation and heat. For outdoor applications, weather stability is an important criteria in material selection. For use in high temperature ( above 70℃, for example ), various grades are available that can provide additional protection against degradation ( oxidized, aging) under any severe climates. TPU can be used over a wide range of temperatures. While Ester grade can withstand temperatures up to 130℃, Ether grade can withstand up to 90℃. The table below shows the comparison of TPU to other plastics to other plastics in respect to degradation.

Properties	TPU Ester Base		PVC		NBR	CR	NR
Properties	95A	85A	85 PHR	80 PHR	NBR	CR	NR
Tensile /MPa initial	34.3	25.3	16.0	16.3	11.6	10.3	16.3
after aged**	51.3	42.4	14.6	18.1	9.8	9.6	5.6
variation ﹪	150	168	91	111	85	93	34
Elongation﹪ initial	700	517	308	350	400	400	450
after aged	460	600	213	238	188	238	450
variation ﹪	66	116	69	68	47	60	0

**Test Time：35 days

Low Temperature Flexibility

TPU can withstand temperature down to -30℃ while mechanical and physical properties are still maintained. Most importantly, TPU will not become brittle and can thus be utilized as a replacement for PVC. In this respect, TPU can be used for applications that require superior low temperature flexibility.

Microbiological Resistance

Polyether-based thermoplastic Polyurethane exhibits excellent resistance to microbiological attack. The table below shows some comparative results of microbial degradation from various elastomers materials.

Microbe

TPU

Ether base

PVC

NBR

95A

85A

Mildew (1)

Other Microbe

>30﹪

>60﹪

>30﹪

>60﹪

>30﹪

>60﹪

<10﹪

>10﹪

<10﹪

Gas Permeability

TPU can be easily processed by high frequency or hot plate welding and has been widely used in inflatable end-applications. The diffusion coefficient is a material constant which specifies the volume of gas that will pass through a test specimen of known surface area and thickness in a fixed time, with a given partial pressure difference. The diffusion coefficient varies to certain extent depending on the type of gas in questions. Generally speaking, TPU Ester series has superior gas permeability to Ether grade.

Biocompatibility

TPU exhibits superior biocompatibility. With the characteristics of sterilization, anti- allergic, without creating the source of heat and agitation to parts, TPU are widely utilized in medical, sanitary, sport, or protective devices.