Speaker: Dr. Lu, Chu-Hua Chang’s Lab 10/26/2009 Reference: Ring-Opening Polymerization Mechanisms,...
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Transcript of Speaker: Dr. Lu, Chu-Hua Chang’s Lab 10/26/2009 Reference: Ring-Opening Polymerization Mechanisms,...
Speaker: Dr. Lu, Chu-HuaChang’s Lab10/26/2009
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
OutlineROP: ring opening polymerizationImportance of ROPNylon (polyamide) (Cyclic amide monomers)Character of ROPMonomer 1: OxiraneMonomer 2: AcetalMonomer 3: Cyclic esterMonomer 4: phosphazenesMonomer 5: siloxaneSummary
2Conventional Radical Polymerization
Importance of ROP
3
conversion0% 100%M n
Living Radical Polymerization and ring-opening polymerization
Condensation Polymerization
High Mn high
viscosity and low
solubilityLow 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 BedPictures from wikipedia.org
Nylon 66 BagNylon 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。 www.asiateck.com.tw
Characteristics of ROP
6
Using cyclic monomersUsing “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 Z ]nn RZ
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 initiatorCH2 CH2
OCH2 CH CH3
OCH2Cl
CCH2
CH2
OCH2Cl
CH2
CH2
CH2
O
EOPEO POPPOCH2 CH2
CH2 CH2
O
CH2 CH2
CH2 CH2
CH2
CH2O
CH2
CH2 CH2
CH2
CH2
OCH2
CH2THFPTHFPU 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 (Pluronic@): micelles in water because of hydrophilic PEO and hydrophobic PPO
O
EO units
HO
H
Hydrogen bonding
O
PO units
HO
methyl screening
H
CHH
H
Mesoporous silica as a catalyst substrateFrom. 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 monomersCationic ROP polymerization only for cyclic
imine monomers
Acetal: O&C-alternate cyclic monomers Cationic ROP polymerization only for cyclic
acetal monomers
NH
CH2 CH2
CH2 CH2
CH2 N H
CH2 CH2S
CH2 CH CH3S
CH2
CH2 CH2
S
RC
R
CH2
CH2S
CH2 OCH2O
CH2
CH2
OO
CH2 CH2
O
CH2
O O
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.orgUsed for guitar picks
Monomer 3
15
Cyclic ester monomers:
O
O
R OH +
Sn(Oct)2or AlEt3/Toluene
R OO
OHn
OO
O
O
e-caprolactone
R OH +
Sn(Oct)2or AlEt3/Toluene
R OO
O
Hn
lactide
PCL
PLAO
O
PLA cups PLA bags
OH
O
OH
lactic acidCorn Fermentation
From wikipedia.org
PCL scaffold for tissue engineering
Monomer 4
16
Polyphosphazenes:A flame retardant Materials
PN P
NPNR R
RR
RR R
O COOH
:
ROP
50wt% Char Yield !!
1000 oC flameblack 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
OSiO
SiOSi O
Si n
PDMS
crosslinkingSilicon Rubbers
ROP
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