D)Antioxidants 13.Which of the following is not the requirement for matrix used in composites? A)Ability to adhere to the fibers B)Higher stiffness compared with reinforcement C)No significant chemical reaction between the two phases D)Thermochemical compatibility between the fibers and matrix material 14 is not a structural adhesive. A)casein B)urea-formaldehyde C)phenol-resorcinol-formaldehyde D)poly (vinyl acetate) 15.Which advantage do smart polymeric materials offer designers? A)Eliminate selection problems B)Reduce raw materials costs C)Adapt to environmental changes D)Reduce processing 16.Which of the following comparison is not correct? A)Thermal conductivity:metal <plastics B)Thermal expansion:metal>plastics C)Density:metal plastics D)Thermal conductivity:metal>plastics 17.Which of the following polymers can not be selected when high dimensional accuracy must be maintained? A)high-density polyethylene B)nylon 6/6 C)fluorocarbons D)polyester 18.An elastomer with great resistance to gas permeation can serve as inner tubes,gas hoses,tubing. diaphragms anr B)Butyl rubber(IIR) C)Neoprene D)EPR and EPDM 19.An elastomer has physical cross-links in the"network"structure. 箱4而 第 4 页 D) Antioxidants 13. Which of the following is not the requirement for matrix used in composites? A) Ability to adhere to the fibers B) Higher stiffness compared with reinforcement C) No significant chemical reaction between the two phases D) Thermochemical compatibility between the fibers and matrix material 14. _____________is not a structural adhesive. A) casein B) urea-formaldehyde C) phenol-resorcinol-formaldehyde D) poly (vinyl acetate) 15. Which advantage do smart polymeric materials offer designers? A) Eliminate selection problems B) Reduce raw materials costs C) Adapt to environmental changes D) Reduce processing 16. Which of the following comparison is not correct? A) Thermal conductivity: metal < plastics B) Thermal expansion: metal > plastics C) Density: metal > plastics D) Thermal conductivity: metal > plastics 17. Which of the following polymers can not be selected when high dimensional accuracy must be maintained? A) high-density polyethylene B) nylon 6/6 C) fluorocarbons D) polyester 18. An elastomer with great resistance to gas permeation can serve as inner tubes, gas hoses, tubing, diaphragms A) NR B) Butyl rubber (IIR) C) Neoprene D) EPR and EPDM 19. An elastomer has physical cross-links in the “network” structure