ISSN:
0021-8995
Schlagwort(e):
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Maschinenbau
,
Physik
Notizen:
Various dip films with different amounts of F/R resins, polybutadiene latex, styrene/butadiene/vinyl pyridine terpolymer latex, and/or with carboxylated butadiene latex were prepared on a Teflon-coated hot plate by spraying the properly formulated dip mixes using a Binks air gun. These dip films were cured at 300°F in hot air oven between two Teflon plates. A DDV-IIC Rheovibron instrument was used to measure elastic modulus (E′), loss modulus (E″), and tan δ (E′′/E′) of different dip films. Dip films with higher F/R resin (11 vs. 7%) concentration gave higher tan δ values which peaked between -20 and -30°C. Films with higher resin concentrations were also found stiffer (higher E′), if all other ingredients of the films were identical. Dip films, where more than 40% of the film ingredient was polybutadiene, showed a phase-separated glass transition temperature for polybutadiene between -60 and -90°C. Films, with 40% polybutadiene and 7.0% F/R resin and the rest of the ingredients being styrene/butadiene/vinyl pyridine and other additives such as wax, silanes, etc., gave two distinct glass transition temperatures: one between -60 and -80°C for polybutadiene and the other for complex between F/R resin and vinyl pyridine around -20 and -30°C. Tire cords coated with dip mixtures of lower tan δ values in the -20 to +20°C range gave better fatigue performance in the Gristmill tire test at room temperature. Tire cords coated with dip mixtures containing 40% polybutadiene and 7.0% F/R resin exhibited phase separated two distinct glass transition peaks in the temperature ranges of -60--90°C and -20--30°C. Films of the above formulations showed low modulus and high elongations. Cords coated with the above dip mixtures gave good fatigue performance in the Firestone cold wheel test at -50°C. It so happens that, in this temperature range of -30--60°C, the above phase-separated dip films go through a minimum damping value and, therefore, give superior tire performance.
Zusätzliches Material:
5 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/app.1990.070400723
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