GB2257975A - Polymerisation method - Google Patents
Polymerisation method Download PDFInfo
- Publication number
- GB2257975A GB2257975A GB9211995A GB9211995A GB2257975A GB 2257975 A GB2257975 A GB 2257975A GB 9211995 A GB9211995 A GB 9211995A GB 9211995 A GB9211995 A GB 9211995A GB 2257975 A GB2257975 A GB 2257975A
- Authority
- GB
- United Kingdom
- Prior art keywords
- monomer
- solvent
- polymerisation
- initiator
- molecular weight
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K19/00—Liquid crystal materials
- C09K19/04—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit
- C09K19/38—Polymers
- C09K19/3833—Polymers with mesogenic groups in the side chain
- C09K19/3842—Polyvinyl derivatives
- C09K19/3852—Poly(meth)acrylate derivatives
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F2/00—Processes of polymerisation
- C08F2/04—Polymerisation in solution
- C08F2/06—Organic solvent
Abstract
A method of controlling molecular weight of acrylate type liquid crystal polymers during polymerisation where the appropriate monomer is dissolved in a suitable solvent followed by addition of an initiator and heating of the mixture. Control of the molecular weight is achieved by use of appropriate concentration of monomer in the solvent. Typically, initiators such as AIBN and benzoyl peroxide can be used with solvents such as dichloroethane, dichloromethane, dimethylsulphoxide and toluene. A calibration chart can be constructed of degree of polymerisation against concentration of monomer in the solvent, with the result that for a given desired degree of polymerisation of an acrylate type liquid crystal polymer the corresponding required concentration of monomer in solvent can be determined.
Description
POLYMERISATION METHOD.
This invention relates to a method of polymerisation, and more particularly to a method of free radical polymerisation of acrylate type liquid crystal polymers.
Liquid crystal polymers (LCP) are well known and are used in the electro-optical device industry, for example in optical storage devices, in non-linear optical devices and in pyroelectric devices, see for example GB 2146787A and Makromol Chem h pp2639-47 1985.
It is well documented in the relevant literature (eg Sagane and Lenz,
Polymer Vol RO pp2269-2278 1989 and Portugall et al, Makromol Chem 183 pp2311-2321 1982) that molecular weight is an influencing factor in thermal properties of LCPs. There are numerous instances in the literature of LCPs synthesized with varying molecular weights, eg Zentel & Ringsdorf, Makromol. Chem. Rapid Commun 5 pp393-398 1984 and Fischer & Eisenbach, Makromol. Chem. Rapid Commun. 9 pp503-511 1988, but there is no method by which control of molecular weight during synthesis can be achieved.
It is the aim of this invention to provide a method for control of molecular weight during polymerisation of acrylate type monomers, where acrylate type polymers include such polymers as polyacrylates, polymethacrylates, polychloroacrylates and polyfluoroacrylates.
According to this invention a method of controlling molecular weight of acrylate type liquid crystal polymers during polymerisation comprises:
1. taking required amount of appropriate monomer,
2. dissolving the monomer in a suitable solvent,
3. addition of an initiator to the monomer and the solvent,
4. heating the initiator, monomer and solvent,
characterised in that
control of molecular weight is achieved by use of appropriate
concentration of monomer in the solvent.
Typical methods of polymerisation will be apparent to those skilled in the art, and include those detailed in GB Application No 9014688 and standard texts such as Portugall, Ringsdorf & Zentel, Makromol.
Chem. 183 pp2311-2321 1982 and also Guglieminetti, Decobert & Dubois,
Polymer Bulletin 16 pp411-418 1986.
Typical suitable solvents include Dichloroethane (DCE), Dichloromethane (DCM), Dimethylsulphoxide (DMSO) and Toluene. Care must be taken to inhibit evaporation of the solvent during polymerisation in order that monomer concentration in the solvent is maintained as constant as is possible.
Suitable initiators include thermally promoted free radical initiators, typically such as azo-iso-butyronitrile (AIBN) and benzoyl peroxide.
During polymerisation typical optimum temperatures for polymerisation container holding environment (eg an oil or water bath) will depend upon the initiator chosen. Where the initiator used is AIBN, then optimum temperatures are typically between about 50"C and 60"C, although higher temperatures, eg up to 800C, can also be used where applicable.
Maximum solubilities of monomer in solvent will be apparent to those skilled in the art, and will depend upon such factors as the type of monomer and the solvent used.
The invention will now be described by way of example only, and with reference to the following figures
Figure 1 is a graph of degree of polymerisation against concentration of monomer of Formula I.
Figure 2 is a graph of degree of polymerisation against concentration of monomer of Formula II.
Monomer of formula I was dissolved in DCE at varying concentrations.
The initiator used is lwt% AIBN and bath temperature was 55 C.
Formula I
Table 1 gives the results for such polymerisations. Mw is the weight average molecular weight and Mn is the number average molecular weight.
MW/Mn is the polydispersity of the polymer. The degree of polymerisation (DP) is defined as the average number of repeat units in the polymer derived from
Molecular weights were measured by Gel Permeation Chromatography (GPC), using Merck LiChrogel PS400 and Polymer Laboratories PLGel lOm columns in series, and calibrated against Polymer Labs polystyrene standards with molecular weights ranging from 800 to 3040000. Samples were run in
THF at room temperature, with a flow rate of 1.0 ml/min., and with an internal standard of Toluene.
Table 1
Conc. (g cm-3) Mn Mw ; (DP) Units 0.050 6810 8170 1.20 13 0.075 7760 10160 1.31 15 0.100 8810 13020 1.48 17 0.150 11260 18630 1.65 22 0.200 14160 32790 2.31 28 0.300 23500 106600 4.53 46 0.400 40900 198700 4.86 80 Figure 1 is a graphical representation of DP against concentration of monomer of the data of Table 1.
Figure 2 is also a graphical representation of DP against concentration of monomer, where monomer of Formula II is polymerised under the same conditions as described above for the polymerisation of monomer of
Formula I.
Formula II
Table 2 gives Mn, Mw, MW/Mn and DP data measured for monomer of Formula
II for varying concentrations of AIBN.
Table 2
Conc. (g cm-3) Mn Mw iWMn (DP) Units 0.050 7830 10260 1.31 18 0.067 9660 15150 1.56 22 0.100 17460 35600 1.48 17
Claims (8)
1. taking required amount of appropriate monomer,
2. dissolving the monomer in a suitable solvent,
3. addition of an initiator to the monomer and the solvent,
4. heating the initiator, monomer and solvent,
characterised in that
control of molecular weight is achieved by use of appropriate
concentration of monomer in the solvent.
2. A method according to claim 1 wherein the the solvent is inhibited
from evaporation.
3. A method according to any of the preceeding claims where the
initiator is azo-iso-butyronitrile.
4. A method according to claim 1 or claim 2 wherein the initiator is
benzoyl peroxide.
5. A method according to claim 3 wherein polymerisation is within a
container having a temperature of between about 50"C and about 60"C.
6. A method according to any of the previous claims wherein the solvent
is dichloroethane.
7. A method as substantially hereinbefore described and with reference
to figure 1.
8. A method as substantially hereinbefore described and with reference
to figure 2.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB919116340A GB9116340D0 (en) | 1991-07-26 | 1991-07-26 | Polymerization method |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB9211995D0 GB9211995D0 (en) | 1992-07-15 |
| GB2257975A true GB2257975A (en) | 1993-01-27 |
| GB2257975B GB2257975B (en) | 1995-04-12 |
Family
ID=10699160
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB919116340A Pending GB9116340D0 (en) | 1991-07-26 | 1991-07-26 | Polymerization method |
| GB9211995A Expired - Fee Related GB2257975B (en) | 1991-07-26 | 1992-06-05 | Polymerisation method |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB919116340A Pending GB9116340D0 (en) | 1991-07-26 | 1991-07-26 | Polymerization method |
Country Status (1)
| Country | Link |
|---|---|
| GB (2) | GB9116340D0 (en) |
-
1991
- 1991-07-26 GB GB919116340A patent/GB9116340D0/en active Pending
-
1992
- 1992-06-05 GB GB9211995A patent/GB2257975B/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| GB2257975B (en) | 1995-04-12 |
| GB9211995D0 (en) | 1992-07-15 |
| GB9116340D0 (en) | 1991-09-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5637646A (en) | Bulk radical polymerization using a batch reactor | |
| Catala et al. | Living radical polymerization: kinetic results | |
| US5057560A (en) | Thermotropic copolymer hydrogels from N,N-dimethylacrylamide and methoxy-ethyl (meth) acrylate | |
| Higaki et al. | Dynamic formation of graft polymers via radical crossover reaction of alkoxyamines | |
| Kröger et al. | Light controlled solubility change of polymers: Copolymers of N, N‐dimethylacrylamide and 4‐phenylazophenyl acrylate | |
| CA2147331A1 (en) | Gels with thermotropic properties | |
| Cameron et al. | Effects of poor solvents on radical-radical termination of polymerization | |
| CN111440279B (en) | Preparation method of block polymer with adjustable molecular weight distribution | |
| GB2257975A (en) | Polymerisation method | |
| JPS6372784A (en) | Ferroelectric polymer liquid crystal | |
| JPS557855A (en) | Preparation of non-aqueous polymer dispersion | |
| Bressers et al. | Thermally and light-induced polymerization of ethyl acrylate and methyl methacrylate, studied by DSC | |
| Grignard et al. | Controlled synthesis of carboxylic acid end‐capped poly (heptadecafluorodecyl acrylate) and copolymers with 2‐hydroxyethyl acrylate | |
| Schwabe et al. | Relaxation Processes of Poly (tert‐butyl acrylate) Chemically Confined via Hydrogen Bonds | |
| Thakur et al. | Studies on the kinetics of free‐radical bulk polymerization of multifunctional acrylates by dynamic differential scanning calorimetry | |
| Biasutti et al. | Substituent effects in the catalytic chain transfer polymerization of 2-hydroxyethyl methacrylate | |
| Hou et al. | A copper‐based reverse atom‐transfer radical polymerization process for the living radical polymerization of polyacrylonitrile | |
| Baruah et al. | Experimental investigation on high conversion free‐radical polymerization of behenyl acrylate | |
| Rzayev et al. | Polymerization of sterically congested α‐alkylacrylates under high pressure | |
| Bhadani et al. | Kinetics of nitrogen dioxide initiated polymerization of acrylamide | |
| Fanood et al. | Aqueous solution polymerization of acrylamide at low conversions: 1. Kinetics and transfer studies | |
| Cuervo‐Rodriguez et al. | Free‐radical copolymerization of ethyl α‐hydroxymethylacrylate with methyl methacrylate by reversible addition–fragmentation chain transfer | |
| JPS5536230A (en) | Antifouling coating compound | |
| Ito | Evaluation of Termination Rate by the Free Volume Thoery in Radical Polymerization | |
| Yamada et al. | Preparation and polymerization behavior of 2‐[2, 2, 2‐tris‐(alkoxycarbonyl) ethyl] acrylic ester as a sterically congested monomer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732E | Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977) | ||
| 732E | Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977) | ||
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20040605 |