Physical and chemical properties of aramid 1313

Aramid 1313 is a high-tech special fiber, which has excellent heat resistance and mechanical properties, not only good breathability and wetness, but also long heat resistance life, wear resistance, good resistance to multiple bending, and resistance to various chemical reagents, and is an important material for making flame retardant and heat insulation protective clothing.

Aramid 1313 has high breaking strength and high elongation, thus good abrasion resistance, durable and wearable. Low stiffness and high elongation characteristics make it have the same spinnability as ordinary fibers, soft hand feel and comfortable to wear.

(1) Heat resistance performance. In the crystal of aramid 1313, hydrogen bonds are arranged in two planes, thus forming a three-dimensional structure of hydrogen bonds. Due to the extremely strong hydrogen bonding, it has a stable structure and can maintain a high strength in the general high temperature state. In 177 ~ 200 ℃ working temperature, time up to 20000h can still maintain the original strength of 65% ~ 70%.

(2) Flame retardant performance. Aramid 1313 due to its own inherent structural characteristics, in the flame is not extended combustion, limited oxygen index of 29% ~ 32%. It is a flame-retardant fiber, will not burn in the air, and does not contribute to combustion, has self-extinguishing, no molten drops. When the temperature exceeds 400 ℃, the fiber gradually brittle, carbonization, until decomposition, and will not produce molten droplets. Aramid 1313 smoke density and toxic gases emitted during combustion are less than other fibers.

(3) Thermal and wet comfort. The so-called thermal and humid comfort refers to the conditions under which people are more satisfied with the thermal environment. The more basic condition of human thermal comfort is to maintain the body's thermal balance, that is, the balance of energy exchange between the body's own heat production and heat dissipation to the environment. In the case of high ambient temperature (33 ℃ or more), the temperature difference between the human body and the environment is very small, and there is even an inverse temperature difference, which can be adjusted by the human body independently, and then the permeability of clothing is particularly important. Through the moisture absorption of several fireproof fabrics and clothing comfort test, it can be concluded that the heat and moisture comfort performance of aramid due to other fabrics.

(4) Chemical resistance. Aramid 1313 good chemical resistance, can resist most acids, long-term impregnation in hydrochloric acid, nitric acid and sulfuric acid, strength slightly decreased; good alkaline resistance, but long-term in sodium hydroxide, strength decreased; it can resist most bleaching agents and solvents, in sodium hypochlorite, a slight loss of strength; stable to oxides, in 250 ℃ under the action of corrosive gases, strength still maintain 60% of room temperature; in the dew point of acid Above the temperature with antioxidant effect, but below the dew point, due to the concentration of sulfuric acid gathered on the fiber, the strength tends to decline.

(5) radiation resistance. Aramid 1313 has strong radiation resistance, and still has high residual strength under the irradiation of β-rays and γ-rays. Such as in 50kV of X-ray radiation 100h, its strength to maintain the original 73%, and at this time the polyester and nylon has become powder. Therefore, aramid 1313 is suitable for making work clothes in flammable and explosive environment and materials used under high temperature.