Thermoplastic polymers transform into a rigid structure on cooling from a heated plastic condition. True or False

What polymer derived from acetylene gas is called polychloroprene (neoprene)?

In engineering, ceramic, metallic and polymeric materials are used; select their order based on the intensity of their intermolecular bonding forces: a. Ceramic > metallic > polymericb. Polymeric > metallic > ceramicc. Ceramic < metallic < polymericd. Metallic > ceramic > polymeric

Q4:- Compare between thermoplastic and thermosetting polymers.

An unknown polymer sample was found to have the following molecular weight distribution: Molecular weight range 8,000 - 20,000 20,000 - 32,000 32,000 - 44,000 44,000 - 56,000 56,000 -68,000 68,000 -80,000 80,000 - 92,000 Having a DP=763, which of the following common polymers is this sample? Xi 0.05 0.15 0.21 0.28 0.18 0.10 0.03 Wi 0.02 0.08 0.17 0.29 0.23 0.16 0.05 Select one: O a. Polymethylmethacrylate with a monomer molecular weight of 100.121 g/mol O b. Polystyrene with a monomer molecular weight of 104.15 g/mol Polycarbonate with a monomer molecular weight of 61.0168 g/mol O c. O d. Polyvinyl chloride with a monomer molecular weight of 62.498 g/mol Polypropylene with a monomer molecular weight of 42.08 g/mol O e.

Which of the statements below are accurate regarding the stress-strain behavior of polymers: (This question has more than one correct answer) а. Strain softening happens in elastomers where the deformation gradually leads to a decrease in stress under constant strain rate b. As temperature is reduced, the necking behavior of plastic tensile bars completely disappears С. The slope of the stress-strain curve for totally elastic and brittle polymers is always positive d. The stress-strain curve for vulcanized elastomers has a greater slope than unvulcanized polymers throughout

Compression molding is a manufacturing process in which the molding material is preheated then placed in an open mold cavity where the compressive action of the punch forces the polymer into the desired shape as shown in the figure below. Based on your understanding of the behavior of polymers, which of the statements below regarding compression molding of polymers are accurate? Punch Cavity C. -Upper mold half Charge 41 (1) -Lower mold half Knock-out pin V, F |x.F (2) and (3) Molded part a. Lower operating temperatures are more desirable as they reduce viscosity making it easier to fill the cavity b. This process can only be used for thermosets as they can thermally cure from monomer state This process can be used for both thermosets and thermoplastics as they can both be thermally shaped d. This process is suitable for rubber, PVC and polymethyl methacrylate

The 3d printing approach shown below is fused deposition modelling (FDM), where feedstock polymer is fed into the heated printer nozzle and deposited onto the platform to form the final object in the desired geometry. Which of the polymers below are suitable for this process and what nozzle temperature should be used for that material? (This question has more than one correct answer) Material spool Heater element Object/Model * Nozzle Build platform

what are the advantages and disadvantages of making a leaf-spring for a commercial vehicle using pultruded Kevlar-fibre reinforced polyester resin?  please do not answer with short sentences, I am looking for more in depth and academic answer.  can you please mention the references

The answer is one of the options below please solve carefully and circle the correct option Please write clear .