งานนำเสนอกำลังจะดาวน์โหลด โปรดรอ

งานนำเสนอกำลังจะดาวน์โหลด โปรดรอ

Part II: Classification of polymer. Classification of Polymers (ref. 4 p.8-23) 1.By origin: natural polymers, semi-synthetic polymers, synthetic polymers.

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งานนำเสนอเรื่อง: "Part II: Classification of polymer. Classification of Polymers (ref. 4 p.8-23) 1.By origin: natural polymers, semi-synthetic polymers, synthetic polymers."— ใบสำเนางานนำเสนอ:

1 Part II: Classification of polymer

2 Classification of Polymers (ref. 4 p.8-23) 1.By origin: natural polymers, semi-synthetic polymers, synthetic polymers 2.By response to temperature: thermoplastics, thermosets 3.By polymerization methods: addition(chainwise), condensation (stepwise) 4.By architecture of chain: linear, crosslink, branched, dendritic 5.By no. of monomer types in polymer: homopolymer (PE, PP, PS, PVC, PMMA, PC, PET), copolymer (SBR, NBR), terpolymer (ABS) 6.By orientation of polymer chains: amorphous, semi- crystalline

3 Classification(1) : By origin Ref: พิชิต เลี่ยมพิพัฒน์ พ. ศ polymer inorga nic orga nic synthe tic natura l Natura l synthe tic soil san d adhesivefiber pain ts plasticrubbe r glass brickscement ceramics โพลิซักกา ไรด์ (polysaccha rides) protein โพลิไอโซพรีนในรูปของ ยางธรรมชาติ (polyisoprene) collage n Kesine (from milk) starch celluloseChitin, Chitosan - silicone rubber - boron nitrile

4 Examples of some natural polymers

5 Examples of some synthetic polymers -Polymers originated from ethylene -Polymers with O in molecules -Polymers with O and N in molecules -Thermosetting Polymers

6 Ref: พิชิต เลี่ยมพิพัฒน์ พ. ศ Polymers Originated from Ethylene

7 Polymers Originated from Ethylene (cont.) Ref: พิชิต เลี่ยมพิพัฒน์ พ. ศ Polyvinylidine chloride

8 Ref: พิชิต เลี่ยม พิพัฒน์ พ. ศ.2542 Polymers with O in molecules

9 Polymers with O and N in molecules The 3 most important are: polyester, polyamide, polyurethane

10 Ref: พิชิต เลี่ยมพิพัฒน์ พ. ศ Polymers with O and N in molecules

11 Ref: พิชิต เลี่ยมพิพัฒน์ พ. ศ Thermosetting Polymers Phenol-formaldehyde Urea-formaldehyde

12 Thermosetting Polymers (cont.) Melamine-formaldehyde

13 Classification(2): Response to temperature Thermoplastic - ex. linear and branched polymers Polymers held together by 2 nd bonds. When T 2 nd bonds break lose polymer flow Thermoset - Polymer chains held together with primary bond (crosslink) bond btw. polymers and inside polymers break at same temp. polymer degrade special case ex. Cellulose held by several 2 nd bonds(hydrogen bonding) but exhibit thermoset behavior  modified to thermoplastic by making “cellulose acetate” ex. Polytetrafluoroethylene(teflon, PTFE) held by several 2 nd bonds (van der Waal force btw. F-F) but exhibit thermoset behavior

14 Polymer Thermoplastic Elastomer Thermoset Crystalline Amorphous ( lightly cross linked) (heavily cross linked ) Network Cross linked polymers Linear/branched polymers (no cross linked)

15 Bonding in polymers Type of bonds –Primary covalent –Hydrogen bond ex. (-CO-NH-) –Dipole interaction –van der Waals (special case: PTFE(Teflon) has very strong van der Waals force that Teflon cannot melt) –ionic secondary bond (Ref:S.L. Rosen, John Wiley & Sons 1993) Bonding in polymers is relevant to characteristic thermal response of the polymers

16 Bonding in polymers - Primary Bonds: - Secondary Bonds: covalent Type of bonds Dipole interaction van der Waals interaction Hydrogen bond ionic bond

17 Bond distances and strengths  = depth of potential energy required to break the bond ref.:S.L. Roson,John Wiley &Sons 1993

18 Bond Parameters Approximate bond strength and interatomic distances of the bond - note that primary covalent bond is much stronger than secondary bond. ดังนั้น primary covalent bond dissociate last when kT reach its activation energy) ref.:S.L. Roson,John Wiley &Sons 1993

19 Ref: พิชิต เลี่ยมพิพัฒน์ พ. ศ Model structures of thermoplastic vs. thermoset thermoplastic thermoset

20 Common Thermosetting Polymers (Ref: พิชิต เลี่ยมพิพัฒน์ พ. ศ. 2542) -Amino (have N in structure) - Urea - Melamine -Epoxy -Phenolic -Unsat. Polyester -Silicone -Polyurethane Urea-formaldehyde


ดาวน์โหลด ppt Part II: Classification of polymer. Classification of Polymers (ref. 4 p.8-23) 1.By origin: natural polymers, semi-synthetic polymers, synthetic polymers.

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