Performance Properties

ACE 1055 delivers excellent performance for intermediate automotive and similar applications. In aging tests, a typical compound made from ACE 1055 has good heat resistance in air and in typical automotive transmission fluids or automotive engine oils for 1 week at 150°C and for six weeks at 135°C. The low temperature rating for an ACE compound can vary from –30 to –40°C.

Compounds made from ACE 1055 have a relatively low density which contributes to a low cost per unit volume, and weight reduction possibilities for parts. A typical density for a compound with 60 phr of carbon black is 1.20 g/cc. This compares favorably to the higher compound densities of chlorinated products like ECO and CPE. Thus cost comparisons should be done on a cost per volume basis.

ACE 1055 co-polymer is halogen free and does not require a lead stabilizer.

Applications

The combination of properties of ACE 1055 compounds allow them to be used in many automotive applications. The product should be considered as a material of choice for applications requiring heat resistance and exposure to transmission fluid or engine oil, with intermediate performance between Vamac® and lower performance materials such as ECO and CPE. Key applications include the following: Turbo Hose – Cold Side, Transmission Oil Cooler Hoses, Power Steering Hoses, Molded Air Ducts, Fuel Hose Cover and other performance applications.

Polymer Information

ACE 1055 has a Mooney viscosity (ML [1+4 at 100°C]) of 16 and a density of 1.03 g/cc. The polymer is clear to white in color and it has a mild acrylic odor. It is available in 25 kilogram bales. Total volatiles content is less than 0.7%.

Handling Precautions

ACE 1055 contains small amounts of residual acrylate monomer; adequate ventilation should be provided during mixing and processing to prevent worker exposure. Additional information may be obtained in DuPont Material Safety Data Sheet (MSDS).

Heat Resistance

Heat resistance in air is a very important property for elastomeric compounds. There are several guidelines for defi ning acceptable heat resistance in air using the heat aging tests as outlined in ASTM D 573. Three of the main failure criteria are increase in hardness of 15 points, decrease in elongation to 50% of original value and decrease in tensile strength by 30% or more.

The results of the testing are very much a function of the time and temperature of the tests. A typical compound made from ACE 1055 will meet the following heat aging requirements in air.

• One week at 150°C (302°F)
• Six weeks at 135°C (275°F)

Fluid Resistance

Several different ACE 1055 compounds were evaluated in different fluids for different times and temperatures using ASTM D 471. In general, the results shown in the next table are based on ACE compounds that were cured with diamine and that had about 55 phr of black and 10 phr of plasticizer. All of the results were based on fluid aging at 150°C with the exception of one test that was run at 135°C. The test duration was either one week or six weeks. See Table 1. The compounds aged well in all of the above fluids. The compounds aged better in the fluids than in air probably because the oxygen concentration was lower in the fluids versus the oxygen concentration in air.

Table 1

Compression Set

Compression set performance is generally better for ACE 1055 than for chlorinated products such as ECO and CPE. The compounds made from ACE 1055 were tested for compression set using ASTM D 395. Typical values are 70 hours/135°C — 20% set, 168 hours/150°C — 30% set which compares favorably with the 90% obtained for 168 hours/150°C for ECO*.

Low Temperature Properties

A differential scanning calorimeter (DSC) was used to measure the low temperature properties of ACE 1055 compounds. The Tg values ranged from about –30°C (no plasticizer) down to about –40°C (10 phr of plasticizer), meeting most automotive application requirements.

Compound Properties and Formulations

Compound properties and formulation are shown in Table 2.

Table 2

The basic formulation used for the ACE 1055 compound is shown in Table 3.

Table 3

The compounds were mixed on a laboratory internal mixer, sheeted off on a roll mill, then press cured for 5 minutes at 175°C and subsequently post cured for 4 hours at 175°C.

ACE 1055 is also peroxide curable (no diamine is required). This has particular utility for compounds which are designed for hoses where a polyester reinforcement is used. Polyester fibers will degrade in the presence of heat and amines with commensurate loss of properties.

Bin Stability

A study was done on a 70 and an 80 Shore A hardness ACE 1055 compound where the uncured compounds were allowed to age for three months at 50% RH and 23°C (CTCH). In summary there was only a small increase in viscosity with time — i.e., the product demonstrates excellent bin stability which gives clear advantages over lead-free ECO compounds.