Which statement is correct regarding the structure of polymers? Oa. Degree of crystallinity and elongation at break have an inverse relationship Ob. Strength increases at higher temperatures as the material softens O c. The tendency of a polymer to crystallize increases with increasing molecular weight O d. Semi-crystalline polymers are heat treated to increase the crystallinity and improve polymer strength Oe. Amorphous & semi-crystalline polymers have lower strength than crystalline polymers Of. Increasing the degree of crystallinity generally increases polymer strength, elastic modulus, and ductility in semi-crystalline Og. It is desirable to have a ductile-to-brittle transition temperature below room temperature

Which statement is correct regarding the structure of polymers? Oa. Degree of crystallinity and elongation at break have an inverse relationship Ob. Strength increases at higher temperatures as the material softens O c. The tendency of a polymer to crystallize increases with increasing molecular weight O d. Semi-crystalline polymers are heat treated to increase the crystallinity and improve polymer strength Oe. Amorphous & semi-crystalline polymers have lower strength than crystalline polymers Of. Increasing the degree of crystallinity generally increases polymer strength, elastic modulus, and ductility in semi-crystalline Og. It is desirable to have a ductile-to-brittle transition temperature below room temperature

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

See similar textbooks

Similar questions

* ..In silicates, oxygen atoms which are bonded to two silicon atoms are Nonbridging oxygen (NBOS). Bridging oxygen (BOs). * ..Nonbridging oxygen (NBOS) are formed by Faster cooling of liquid glass. O the addition of either alkali or alkaline earth metal oxides to silica. Ceramics are ........ Organic, nonmetallic, crystalline solids. Inorganic, nonmetallic, crystalline solids Inorganic, nonmetallic, noncrystalline solids.
Plastics may exhibit a change in properties as they age, particularly when subjected to elevated temperatures. Material properties such as tensile strength will increase with an increasing temperature as a function of increasing time. True or false.
Question 5: The graph below gives a plot of force versus total sample length in a tensile test of a polymer. The sample is cylindrical, with an initial diameter of 1 cm and an initial length of 10 cm. From the data below, calculate the modulus, yield stress, yield strain, tensile strength, and % elongation. 1200 800 10 12 13 14 15 Lensth (cm) Force (N)
Silica gels are a form of SiO2 characterized by: (This question has more than one correct answer) a. Crystalline lattice b. High internal surface area c. Presence of OH ions d. Can be used as a catalyst support
What is the difference between thermoplastics and thermosets? A)Thermosets are cross-linked, thermoplastics are linear polymers. B)There is no significant difference. C)Thermoplastics cannot be melted, while thermosets can be. D)Thermoplastics are more elastic then thermosets.
1) Assume that a lamina is made using glass fiber and epoxy with the following properties: Er = 74 GPa, v, = 0.27 Em = 6.3 GPa, vm = 0.31 a) Using Rule of Mixtures, calculate and plot the elastic properties of the lamina (E1, E2, G12, v12 ,V21) as a function of fiber volume fraction. b) Comment on the observed trends and maximum values of these properties as a function of volume fraction
Which of the following is correct regarding the degree of crystallinity of semi-crystalline polymers? Semi-crystalline polymers are heat treated to increase the crystallinity and improve polymer strength The tendency of a polymer to crystallize increases with increasing molecular weight Degree of crystallinity and tendency to creep have an inverse relationship Increasing the degree of crystallinity generally increases polymer strength, elastic modulus and ductility in semi-crystalline polymers
8- Which one of the following is not the disadvantages of polymers a. Low strength b. Low softening temperature c. High Elastic modulus d. Low Elastic modulus values
2. Plot the effect of glass temperature on phase transition (Vitrification) in amorphous polymers.
Molecular weight data for some polymer are tabulated here. Compute (a) the number-average molecular weight, (b) the weight-average molecular weight. (c) If it is known that this material's degree of polymerization is 710, which one of the polymers listed in Table 14.3 is this polymer? Why? Molecular Weight Range g/mol 15,000-30,000 Xi Wi 0.04 0.01 30,000-45,000 0.07 0.04 45,000-60,000 0.16 0.11 60,000-75,000 0.26 0.24 75,000-90,000 0.24 0.27 90,000 105,000 0.12 0.16 105,000-120,000 0.08 0.12 120,000-135,000 0.03 0.05
1. The rocker or roller support is commonly used for supporting one end for trusses to allows freedom for expansion or contraction of the members due to a change in temperature or application of loads. 2. Many of the polymer based composites are subject to attack by chemicals or solvents, just as the polymers themselves are susceptible to attack and absorb moisture. 3. If the biological material is produced from toxic substances, it is not compatible with the tissues of the body and may lead to side reactions. 4. Advanced nanomaterials are characterized by their small size and high performance. 5. Without support reactions, the body can move in any direction or wrap around itself. advantages disadvantages. O O O O O O O O