历年真题4（Over the years 4）.doc

历年真题4（Over the years 4） Chapter 1 Structure of polymer chain 1. explain nouns and concepts Equivalent freely jointed chain segments. The mean square end-to-end distance Junfang radius of configuration and conformation 2., two kinds of polymers are known as PE. How do you identify which one is HDPE and which one is LDPE? Give three methods and explain the basis. 3., the average polymerization degree of poly alpha olefin is 500, and the mean square end-to-end distance is 625 Nm2. (1) the rigidity factor sigma of molecular chain rotation is blocked. (2) as a unit of independent motion of macromolecules - chain length B. (3) a large molecule containing the number of segments Z. (4) the number of structural units in each segment. 4. it is assumed that the average polymerization degree of PP is 2000, the bond length is 1.54, and the bond angle is 109.5o. In the theta solvent, the chain length of the equivalent free link chain is B. 5. write the various possible configurations of polyisoprene (excluding bonding isomerism). 6. what is the configuration of a chain? Isotactic polypropylene can through chemical bond (C-C bond) in the same rotation into between, why? 7. what is the structural difference between natural rubber and Guta rubber? Painting structure. 8., if the mean end distance of a free link chain (Dan Xilei) is increased by 10 times, how many times must the polymerization degree be increased? What is the fundamental reason for the flexibility of the 9. molecular chains? What are the physical parameters that characterize the flexibility of polymer chains? How are they defined? (11., PE, PS, II, PP, PAN, PVC, PP, PIB (polyisobutylene) PE and cis 1, 4 polybutadiene, poly (ethylene glycol adipate) polypropylene (Quan Tong) poly two siloxane 10 assuming that PP is in toluene solution at 30 DEG C, the unperturbed dimension (h02/M), =8.35 * 10-4nm, sigma = (h02/hfr2), =1.76, and (1) the chain length of the equivalent free orientation chain of this polypropylene is measu