Speaker: Dr. Lu, Chu-Hua Chang’s Lab 10/26/2009 Reference: Ring-Opening Polymerization Mechanisms, Catalysts, Structure, Utility (1993), edited by Daniel J. Brunelle RING OPENING POLYMERIZATION - A SMART WAY TO IMPROVE CONDENSATION POLYMERIZATION 1

Outline ROP: ring opening polymerization Importance of ROP Nylon (polyamide) (Cyclic amide monomers) Character of ROP Monomer 1: Oxirane Monomer 2: Acetal Monomer 3: Cyclic ester Monomer 4: phosphazenes Monomer 5: siloxane Summary 2 Conventional Radical Polymerization

Importance of ROP 3 conversion 0% 100% Mn Living Radical Polymerization and ring-opening polymerization Condensation Polymerization High Mn  high viscosity and low solubility High Mn  high viscosity and low solubility Low Mn  low mechanical properties and easy leaching Low Mn  low mechanical properties and easy leaching Conventional Radical Polymerization High Mw/Mn for condensation polymerization

Importance of ROP 4 Condensation Polymerization of Nylon 6, 6 ROP of Nylon 6 Nylon 66 Bed Pictures from wikipedia.org Nylon 66 Bag Nylon 6 Yard

Nylon (Polyamide) 5 Nylon ( 尼龍 ) 與其他熱可塑性塑膠相比，在強度、延展性、耐磨性及耐熱 性上提供了卓越的平衡，並有很好的流動性及寬廣的加工成型範圍，使其 成為最普遍被使用的工程塑膠之一。目前市場上有多種商品化 Nylon 材料 可供選擇，如 : Nylon 6/6 、 Nylon 6 、 Nylon 6/10 、 Nylon 6/12 、 Nylon11 、 Nylon 12 、非結晶性 Nylon 及耐衝擊改質 Nylon 6/6… 等。 在各種商品化 Nylon 中， Nylon 6 具有堅韌、耐摩擦的特性，使其成為是 最普遍使用的 Nylon 之一。與 Nylon 6/6 相比，其成型品外觀、耐潛變性 及加工成型性均更加優異 ( Nylon 6 之溫度成型比 Nylon 6/6 大約低 27 ℃ ) ， 此情況使其有較低的模收縮率 ) ，但相對的 Nylon 6/6 比 Nylon 6 有較低的 模數，且吸濕速度較 Nylon 6/6 快 。與其他熱可塑性塑膠相比， Nylon 6 會從空氣中吸收較多的濕氣， 此現象對可加工性、尺寸穩定性和物理特性 造成影響。對 Nylon 6 而言，吸收濕氣會提升其延伸率及韌性但相對會使 其抗拉強度和剛性降低。

Characteristics of ROP 6 Using cyclic monomers Using “ionic” imitator Polymerization: transformation from intra-chain bonds to inter-chain bonds and enthalpy from the ring strain of cyclic monomers. Polymerization without releasing small molecules (cf. condensation polymerization). Polymerization with low activation energy (cf. covalent bond for condensation polymerization). Some cyclic monomers are prepared by chemical modification of α, ω –difunctional monomers for condensation polymerization. Living polymerization (pseudo ionic polymerization): controllable and high molecular-mass polymers (cf. condensation polymerization (equivalent feeding ratios)). R: alkyl chain; Z: O, S, N, P, Si, or -CONH- ， -COO- ， -CH=CH-, and so on.

Monomers, Catalysts and Polymerization 7 continued

Monomers, Catalysts and Polymerization 8

Monomers 1 9 Oxirane: O-cyclic monomers & using alcohol initiator EO  PEO PO  PPO THF  PTHF PU 的軟鏈段組成 ( 保溼化粧品主要成份 )

PEO (PEG) Application 10 Spenco 2nd Skin is a hydrogel sheet, consisting of cross- linked polyethylene oxide, and containing 96% water, supported upon a net of low density polyethylene, which provides strength. The gel, which is capable of absorbing approximately its own weight of wound exudate, is permeable to water vapor and oxygen, but impermeable to water and bacteria. The dressing provides a moist environment upon the surface of the wound and provided that it is not allowed to dry out, the dressing will not adhere to the underlying tissue upon removal. moosejaw.com 氨基酸洗面皂 全 成 份 Dis Water 、 Sodium Lauroyl Glutamate 、 Polyethylene Glycol 400 、 Potassium Laurate 、 1-3Butylene Glycol 、 Methyl Paraben 、 Propyl Paraben 、 Perfume 成份說明 ◎ 聚乙二醇 400(Polyethylene Glycol 400) ：界面活性劑， 防止水分過度流失。 Compete-cosmetic.com

PPO Application 11 PEO-b-PPO-b-PEO triblock copolymer micelles in water because of hydrophilic PEO and hydrophobic PPO Mesoporous silica as a catalyst substrate From. myoops.org

PTHF Application 12 PU Chemistry: PU Structures: Hard domain (aggregation of urethane units via Hydrogen bonding) and soft domain (chain entanglement of alkoxide chains (PTHF) between urethane). PU Elastomers: Hard domains are used to keep the shape of elastomers and soft domains are used to extend when external force is applied. diisocyanate diol Urethane linkages From wikipedia.org Foaming

Monomer 2 13 Imine & sulfide: N- & S-cyclic monomers Cationic ROP polymerization only for cyclic imine monomers Acetal: O&C-alternate cyclic monomers Cationic ROP polymerization only for cyclic acetal monomers

Polyacetal Application 14 Polyoxymethylene (POM): engineering thermoplastic, high stiffness, low friction and excellent dimensional stability. Five engineering thermoplastic: Polyamide (PA, i.e., Nylon 6), POM, polycarbonate (PC, CD substrate), polyphenylene oxide (PPO), Polybutylene terephthalate (PBT). From wikipedia.org Used for guitar picks

Monomer 3 15 Cyclic ester monomers: PLA cupsPLA bags Corn Fermentation From wikipedia.org PCL scaffold for tissue engineering

Monomer 4 16 Polyphosphazenes: A flame retardant Materials ROP 50wt% Char Yield !! 1000 o C flame black char From research.chem.psu.edu

Monomer 5 17 Silicon ( 矽利康 ) Silicon Oil: Polydimethylsiloxane (PDMS) Silicon Oil (PDMS) Lubrication Viscosity of PDMS depends on Mn !! Silicon Ruber Hose

Summary 18 Polymerization without new bonds: cyclic monomers to linear polymer. Ionic initiator or using metal catalyst (coordination) The ring opening polymerization is developed to improve the condensation polymerization by combination of radical polymerization behavior--- initiation. Common ROP polymers: Nylon 6, PEO, PPO, PTHF, POM, PCL, PLA, Polyphosphazenes, PDMS. A chemist should remember the chemical names and the chemical structures of common ROP polymers. Thanks for Your attention