Title of Invention

PROCESS FOR PREPARATION OF CARBONIC ACID ESTERS FROM DIETHANOLAMINE AND POLYMERS THEREOF

Abstract

A novel allyl carbonate monomer called (N-Allyloxycarbonyldiethanolamine bis (allylcarbonate) i.e., NADAC was synthesised from diethanolamine. Thin (200-800 microns) films of the novel homopolymer called Poly (N-Allyloxycarbonyldiethanolaminebis(allylcarbonate)) i.e, PNADAC and correspond¬ing copolymer with allyl diglycol carbonate i.e., poly [PNADAC-co-ADC] were prepared from this novel monomer by its free radical cast polymerisation and ex¬posed to a fission fragment /alpha particle source. The sensitivity of these films to alpha particles was found out as given in literature and compared with that of com¬mercially available CR-39 polymer, poly [PNADAC-co-ADC] copolymer was found to be more sensitive than CR-39 polymer.

Full Text

FORM-2 THE PATENTS ACT, 1970 (39 of 1970) COMPLETE SPECIFICATION (SEE SECTION 10, rule 13) PROCESS FOR PREPARATION OF CARBONIC ACID ESTERS FROM DIETHANOLAMINE AND POLYMERS THEREOF NAME : ADDRESS : Registrar, Goa University. Goa University Campus, Taleigao Plateau, GOA 403 206. NATIONALITY : INDIAN The following specification particularly describes the nature of this invention and the manner in which it is to be performed. GRANTED 23 JUL 2004 30 -11-2004 This invention relates to novel allylic monomer, polymers from this monomer, meth¬ods of preparation of such polymers and use of such polymers for detecting ion¬izing radiations. In accordance to the present invention we have prepared a novel unsaturated carbonic acid ester from diethanolamine by reacting it with unsatur¬ated haloformate. This invention is particularly related to production of allyl carbonic acid esters from amino alcohols like diethanolamine. In production of such monomer, various amino alcohols like ethanolamine, diethanolamine, triethanolamine, 1-amino-2,3-propanediol, 2-amino-1,3-propanediol etc. may be used. Such compounds may be treated with chloroformates of unsaturated alcohols like allyl alcohol or methallyl alcohol to form corresponding unsaturated carbonic acid esters of the amino alcohol type compounds. This reaction is generally carried out in two steps, (a) Preparation of chloroformate of unsaturated alcohol using Triphosgene i.e bis(trichoromethyl)carbonate (b) reaction of the chloroformate with amino alco¬hol compound in presence of suitable basic reagents like Pyridine, dimethylamine, carbonates, hydroxides of alkali or alkaline earth metals such as Na,K Ca, Ba Mg etc. The temperature of the reaction in the first step may be between -5 to 0° C or it may be even lower as maintained by artificial cooling. Thus triphosgene is dis¬solved in suitable organic solvent and decomposed in presence of basic reagents as per the known procedures in literature [Reference may be made to L Cotarca et a/., in Synthesis, p.553, (1996) ] and unsaturated alcohol is added to it at such rates that phosgene generated is always in excess compared to the unsaturated alcohol present in the reaction flask. Subsequently, the chloroformate of unsaturated alcohol so prepared may be re¬acted with required amino alcohol specified above in presence of alkaline agents as mentioned in the first step. A suitable low boiling organic solvent like acetone, benzene, methylene chloride, chloroform etc., may be used. The temperature of the reaction may be room temperature (20-30 °C). The reaction mixture may be stirred for about 1-2 hours. The final product may be recovered by removal of solvent followed by washings by water followed by drying over molecular sieves for about 2-8 days. The structure of compound so formed particularly from diethanolamine and allyl chloroformate has been confirmed from the spectral data given in Example 1. CH2=CH-CH2-OCO-N(CH2-CH2-0-CO-0-CH2.CH=CH2)2 Thus, according to the present invention there is provided a process for the preparation of allylic carbonate monomer from diethanolamine by reacting it with allyl chloroformate at low temperature, in presence of basic reagents. Examples of basic reagents are pyridine, sodium hydroxide, potassium hydroxide. The reaction preferably takes place at low temperaure upto 15°C and over a time period of 2.5 hours. It has been found that it is possible to polymerize the above compound alone in presence of suitable polymerization catalyst/initiators to get a novel homopoiy-mer. It has also been found that the mixture of above novel monomer with other allylic monomer in suitable weight ratio may also be polymerized using suitable cata¬lyst to get a novel mixed/copolymer. Such a polymerization can be carried out by Cast polymerization by filling the mixture of monomeric compound and initiator in a mold prepared using polished glasses and a gasket of inert material like Teflon and a suitable adhesive that is used to bolt the parts of the mold in place. The initiator used for this purpose may be peroxides like Benzoyl peroxide , ditert-butyl peroxide, methyl ethyl peroxide or peroxydicarbonates like isopropyl peroxidicarbonate, Cyclohexylperoxydicarbonates or tert butyl isopropylperoxy carbonate these compounds are to be used in 1 to 5% by weight of monomer or mixture of monomers. It is a known prior art that such unsaturated monomers containing allylic groups can be polymerized to get thin films.lt is also known that during polymerization such allylic monomers suffer from shrinkage and cracks produced due to local overheating. Such problems could be overcome by applying proper pressure to the mold and by using a slow heating process over a period of 4 to 36 hours. Reference may be made to U.S.P 2,379,218 or an article published by W R Dial and his collaborators : Ind. Engg. Chem., 1955, (47), p. 2447. The novel polymers so prepared may be used for detection of ionizing radiations, as Track detectors. It is known that various polymers like polyesters, polycarbon¬ate etc.undergo degradation when irradiated with ionizing particles, alpha par¬ticles, recoil protons , fission products while remaining substantially insensitive to electromagnetic rays (light, UV, X and gamma) and beta radiations. It is also "known that chemical reagents such as strongly basic aqueous solutions attack the degraded parts and non-degraded parts of such irradiated materials differentially. Reference may be made regarding this subject to an article by R L Flischer and his collaborators: Physical Review., 1964, (5A),133, p. A1443. Thus according to prior art methods for detection of ionizing radiations using poly¬mers, a thin (200-700 microns) film of polymer is exposed to and selectively de¬graded by ionizing radiations and then attacked in the degraded parts by warm basic solution like 5-7 N aqueous Sodium or Potassium Hydroxide at tempera¬tures from 50-80°C. By examining the film with effectively collimated light , it is possible to count particle tracks. Various automated techniques like image analysis have also been used for counting the ionizing particle tracks. The sensitivity of such polymers to alpha /fission tracks is determined by fission fragment diameter method for which reference may be made to ; Solid State Nuclear Track detection : Principles, methods & applications by S A Durrani, R K Bull, Pergamon Press, 1987. It is also known from the prior art that homopolymer of ally! diglycol carbonate and its copolymer with diethylene glycol bis(allyl sulphonate) are best sensitive materials to various ionizing radiations , more particularly alpha and fission frag¬ments. Reference may be made to an article by IVI Fujii and coworkers: Nucl. Tracks. Radiat. Meas., 1988, 15(1-4),p. 107. According to the known prior art of characterizing a polymer in terms of sensitiv¬ity to ionizing radiations, as substantially described in above mentioned articles,the commercially available polymeric materials are known to have sensitivity values between 1.0 to 1.2 . It is one of the objective, of present invention to provide polymeric materials hav¬ing better detection characteristics for ionizing radiations , more particularly pro¬viding polymeric track detectors which are homo or copolymer having better sen¬sitivity values than the known materials.lt is expected that a polymeric network which has a sufficiently dense 3D network of polymer chains will act as a more sensitive material to charged particles. A formation of denser 3D networks can be expected from monomers or compositions of monomers that have higher func¬tionality. Thus the present NADAC monomer prepared from diethanolamine and its mixture with another monomer like allyl diglycol carbonate are expected to result into a novel homo and copolymer respectively which have a much denser 3D network of polymer chains and thus acting as a more sensitive charged parti¬cle detector. Thus, thin(200-800 microns) films of the novel homopolymer called Poly (N-Allyloxycarbonyldiethanolaminsbis(allylcarbonate)) referred herein after as PNADAC and corresponding copolymer with allyl diglycol carbonate as mentioned above re¬ferred herein after as poly [PNADAC-co-ADC] are exposed to a fission fragment/ alpha particle source of Cl252 such that the ionizing radiations are incident at right angles to the detector film. The tracks of fission fragment and alpha particles are revealed under microscope after treatment in 6-8 N KOH or NaOH for 2-10 hours at 60-80°C and the diameters of alpha particle and fission fragment tracks are noted to determine the sensitivity. Thus, in the present process, it is possible to prepare thin sheets of polymer i.e., either homoplymer of NADAC monomer or its copolymer with other monomers like ADC, of thickness between 200 microns to 800 microns, and of size varying between 1" x 1" to 12" x 12", using suitable peroxy initiators and suitable plasticisers over a time period preferably from 4 hrs to 48 hours. Examples of peroxy initiators that can be used are benzoyl peroxide, isopropylperoxydicarbonate, cyclohexyl peroxy dicarbonate or t-butylisopropyl peroxydicarbonate. Examples of plasticisers that can be used are like di-iso-octylphthalate, di octyl sebacate, dibutly phthalate, di-(2-ethylhexyl) phthalate. The following examples are illustrative and make clear the objects and advan¬tages of this invention. However, it is to be understood that such examples are not to be construed in a restrictive manner in the scope of invention. Example No.1 Synthesis of (N-Allyloxycarbonyldiethanolamine bis (allylcar- bonate) i.e., NADAC In a 3-neck round bottom flask, 6g (0.0571 moles) of diethanolamine was taken with acetone(dry) 100ml, as solvent. The flask was equiped with a thermometer, guard tube(calcium chloride)and addition funnel. Allyl chloroformate prepared above, 21.61 g (0.1771 molss) was added through the addition funnel till the disappearance of the cloudy precipitate. Pyridine (13.8g, 0.1771 moles) was then added at once taking care the temperature does not exceed 10 °C . Remaining allyl chloroformate was then sdded in a drop wise fashion keeping the tempera¬te of the reaction below 1D°c. The whole reaction was earned over 1.5 h. Ex¬cess of solvent was then removed using vacuum and the mixture was taken in ether and washed several times with water followed by dil. HCI , brine and again with water. The product was then recovered from the ether layer and dried over Sr No. Time (hr) Temperature (°C) 1 0 42.56 2 1 43.79 3 2 45.16 4 3 46.69 5 4 48.45 6 5 50.50 7 6 52.95 8 7 56.02 9 8 60.15 10 9 67.00 11 10 73.00 12 11 80.00 13 12 90.00 Example 3. The above mentioned film was cut into small pieces of size 2 cm x 2 cm and any 6 pieces were used for track detection experiments. All these were exposed to a plancheted Cf252 alpha/ fission fragment source in vacuum (0.1 mbar) at a distance of 5 cm from source for 8 hours. All the 6 pieces were then chemi¬cally etched in 6 N NaOH solution at 75°C for 3 hours. The films were then removed, washed with water and dried. The dried films were then viewed under optical microscope in transmitted light and the circular tracks per view of micro¬scope were counted. The alpha tracks were smaller and fission fragment tracks were bigger in diameter. At 40 X magnification, a total of 50 views were counted in each film and number of tracks per view were averaged. The diameter of 50 different alpha and fission tracks respectively was measured using object microme¬ter of the microscope and was averaged. The sensitivity of the film was then calculated as per the literature method. The sensitivity was found to be 1.46. The results are given in Table No.2 A similar experiment was repeated with commercially available track detector films called CR-39 (250 microns) where chemical etching was done using 6 N NaOH at 70°C and the sensitivity was found to be 1.2. Table No. 2 Determination of sensitivity of homopolymer PNADAC. Sr No. Film No. Diameter of tracks (microns) After 8 hours of etching Sensitivity 1 Ex.1 Alpha tracks fission tracks 1.46 16.25 37.50 2 Ex.2 16.25 38.75 1.42 3 Ex.3 16.25 37.50. 1.46 4 Ex.4 16.25 37.50 1.46 5 Ex.5 16.25 38.75 1.42 6 Ex.6 16.25 37.50 1.46 Example 4 : The experiment No. 2 was repeated except that a 1:1 (wt. by wt.) mixture of allyl diglycol carbonate (ADC) and NADAC monomer was taken and mixed with 3 % by wt. of IPP as initiator and 1 % by weight of DOP as piasticiser and heated as per the profile given in Table no.3 for 12 hours. A similar mould, to that in example no. 2 was used. After opening the mold a copolymer of ADC & NADAC called poly [PNADAC-co-ADC] of approx. thickness 500 microns and size 7.5 cm x 7.5 cm was obtained. Table No.3 Temperature-time profile used for polymerisation Sr No. Time (hr) Temperature (°C) 1 0 44.03 2 1 45.85 3 2 47.89 4 3 50.20 5 4 52.87 6 5 56.02 7 6 59.82 8 7 64.82 9 8 72.00 10 9 85.00 11 10 86.50 12 11 87.90 13 12 90.00 Example No.5 The experiment No. 3 was repeated except that 6 pieces of co-polymer poly [PNADAC-co-ADC] were used. The exposure to radiation source was carried out in an essentially similar conditions to that in Experiment no. 3 and the films were etched in 6 N NaOH at 75°C for 7 hours. The diameters of alpha and fission frag¬ment tracks were noted and the sensitivity was determined as per the literature pro¬cedure. The sensitivity of this material was found to be 1. 59 The results are given in Table no.4 Table No. 4 Determination of sensitivity of co-polymer, poly [PNADAC-co-ADC] Sr No. Film No. Diameter of tracks (microns) After 7 hours of etching Sensitivity Alpha tracks fission tracks 1 2 3 4 5 6 Ex.1 Ex.2 Ex.3 Ex.4 Ex.5 Ex.6 16.25 16.25 16.25 16.25 16.25 16.25 33.75 35.00 33.75 33.75 35.00 33.75 1.59 1.54 1.59 1.59 1.54 1.59 We Claim : 1. A process for the preparation of polymers of N-Allyloxycarbonyldiethanolaminebis (ally! carbonate) comprising of - (a) preparation of monomer, i.e., N-Allyloxycarbonyidiethanolaminebis (allyl carbonate) by reacting allyl chloroformate with diethanolamine in presence of basic catalyst at low tem¬perature over a period of two hours and (b)cast polymerization of N-Allyloxycarbonyldiethanolaminebis (ailyl carbonate) to prepare homopolymer (PNADAC) or copolymer poly [PNADAC-co-ADC] that are cast into thin sheets for detecting ionizing radiations. 2. A process for the preparation of N-Allyloxycarbonyldiethanolaminebis (allyl carbonate) as claimed in claim 1 wherein the basic catalyst selected is pyridine or alkali metal hydroxide like sodium hydroxide or potassium hydroxide. 3. A process for the preparation of N-Allyloxycarbonyldiethanolaminebis (allylcarbonate) as claimed in claim 1 wherein the temperature is ranging from 5° to 10°C. 4. A process for the preparation of polymers from N-Allyloxycarbonyldiethanoiaminebis (allyl carbonate) as claimed in claim 1, wherein the cast polymerisation step to get either homopolymer or copolymer is consisting of heating, either N-Allyloxycarbonyidiethanolaminebis (allyl carbonate) monomer alone or its mixture (1:1 w/w) with allyl diglycol carbonate, along with piasticizers like di-isooctyl phthalate, dibutyl phthalate, di-(2ethylhexyl) phthalate, and initiators like benzoyl peroxide, isopropyl peroxydicarbonate, t-butyl isopropyl peroxydicarbonate. Dated this 11th Day of December, 2003. To, The Controller Of Patent; Patent Office, Mumbai.

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1291-mum-2003-cancelled pages(30-11-2004).pdf

1291-mum-2003-claims(granted)-(30-11-2004).doc

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1291-mum-2003-correspondence(ipo)-(05-07-2004).pdf

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