פולימרים

if the concentration of initiator in a free radical polymerization reaction is decreased and at the same time the rate constant of propagation is increased theaverage kinetic chain length and average degree of polymerization DP is affected on the follow way

1

מיין לפי

natural rubber, Hevea is sticky,elastic and mechanically weak polymer while Gutta0percha is harder and more non elastic.Both are made of exactly the same monomer material(isoprene) and have the same primary chemical structure. what is the best explanation for their different properties

1

מיין לפי

Two polymers have similar solubility parameters,and can interact strongly by hydrogen bonding interaction. They are mixed together to form a blend. The blend may be described by which of the following statement?

1

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A narrow polymer molecular weight distribution can be achieved in which of the following ways?

1

מיין לפי

A number of extreme changes occur upon chemical crosslinking of polymers. Which one of the statements is not true?

1

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A number of extreme changes occur upon covalent chemical crosslinking of polymers. Which one of the statements is true? (Choose from the following four possibilities)

1

מיין לפי

A number of extreme changes occur upon chemical crosslinking of polymers. Which one of the statements is not correct: (Choose from the following four possibilities)

1

מיין לפי

A polyamide Nylon 7, can be made from the ring opening polymerization of the cycloactam of 7-aminoheptanoic acid or by its direct condensation polymerization of 7- aminoheptanoic acid. If 7-aminoheptanoic acid has a number average molecular weight of 145 and if in both cases the nylon 6 has a number average molecular weight of 25,400 what is the average degree of polymerization DP of each polymer?

1

מיין לפי

If a condensation polymerization is carried out with a mixture of 1 mole of trifunctional carboxylic acid monomer, and 2 moles of a difunctional carboxylic acid monomer, and 4 moles of a difunctional alcohol monomer, what will be the approximate reaction conversion, p, of the polymerization reaction at the gelation point?

1

מיין לפי

Though both cellulose and starch are both made from glucose monomers they have very different mechanical and solubility properties. This difference is due to which of the following?

1

מיין לפי

Discuss, Learn and be Happy דיון בשאלות

if the concentration of initiator in a free radical polymerization reaction is decreased and at the same time the rate constant of propagation is increased theaverage kinetic chain length and average degree of polymerization DP is affected on the follow way

natural rubber, Hevea is sticky,elastic and mechanically weak polymer while Gutta0percha is harder and more non elastic.Both are made of exactly the same monomer material(isoprene) and have the same primary chemical structure. what is the best explanation for their different properties

Two polymers have similar solubility parameters,and can interact strongly by hydrogen bonding interaction. They are mixed together to form a blend. The blend may be described by which of the following statement?

A narrow polymer molecular weight distribution can be achieved in which of the following ways?

A number of extreme changes occur upon chemical crosslinking of polymers. Which one of the statements is not true?

A number of extreme changes occur upon covalent chemical crosslinking of polymers. Which one of the statements is true? (Choose from the following four possibilities)

A number of extreme changes occur upon chemical crosslinking of polymers. Which one of the statements is not correct: (Choose from the following four possibilities)

Though both cellulose and starch are both made from glucose monomers they have very different mechanical and solubility properties. This difference is due to which of the following?