CS273801B1 - Method of isobutylene's grafted copolymers production - Google Patents

Abstract

The invention is a new method of production of grafted copolymers of isobutylene by block polymerisation, based on the fact that the block polymerisation is carried out at -60 to -100 degrees C in the presence of an initiator system, which consists of a component formed by a macromolecular substance containing chorine atoms in the chain bound to secondary and/or tertiary carbons, possibly activated by adjacency of the double bind, the second component is Lewis acid boron chloride, whereas the molar ratio of boron chloride to isobutylene is 50 to 10<-5> with the occurrence of products containing a chemically linked initiator component, corresponding to the used macromolecular substance.<IMAGE>

Description

The invention relates to graft copolymers of isobutylene by block polymerization.

Boron trichloride (BCl-j) together with boron trifluoride (BF-j), titanium tetrachloride (TiClCl), titanium tetrabromide (TiBr ^) and tin tetrachloride (SnCl ^) are included in the group of Lewis acids which require the presence of a protogenic substance, to be able to initiate by the polymerization of isobutylene.

The inactivity of the BCl 3 -isobutylene system in the absence of a protogenic substance has been described by Plesch in 1947 (PH Plesch, M. Polanyi, WA Skinner, 0. Chem. Soc. 257 (1947)) and later by other experts in basic cationic polymerization research. Chmelir, M. Marek, Collect. Czech, Chem. Commun., 32, 3047 (1967), P. Kennedy, SY Huang, C. Freinberg, 3. Polym Sci, Polym Chem Edn. 2801 (1977)). It is apparent from the literature that the polymerization of isobutylene in the absence of a protogenic substance (such as water, hydrogen chloride, hydrogen fluoride) does not occur by BCl 3 alone, both in non-polar, polar and polar environments. In the presence of a protogenic substance (water, hydrogen chloride), the polymerization of isobutylene co-initiated with BCl 3 effectively takes place in a polar medium (e.g. dichloromethane, methyl chloride) only at low temperatures (t <-50 ° C). At low temperatures, however, the polarity of the environment strongly affects the course of the cationic polymerization of isobutylene, and the literature above shows that the isobutylene-BCl 3 -protective system (1? 0 and HCl, respectively) is also unreactive when polymerizing in a non-polar environment. . The inactivity of isobutylene in the block in the presence of the SCl ^ / H ^O system or using BCl ^ alone is demonstrated in Table 1, which summarizes the identical results of our laboratory with the experiments previously described by prof. Kennedy in 1977.

Also the recently discovered BCl 3 / tert -butyl chloride (t-BuCl) initiation system for the polymerization of isobutylene in dichloromethane (L. Toman, S. Pokorny, 0. Singer, 0. Danhelka, Polymer 27, 1121 (1986) is in the absence of dichloromethane unreactive even for a very long period of observation (7 days), as also shown in Table 1.

Probably due to the generally known non-reactivity of isobutylene in the presence of BCl 3 in a non-polar environment (e.g., block polymerization) at temperatures below 40 ° C,

BCl 3 was rejected as a suitable co-initiator for grafting polyvinyl chloride (PVC) with isobutylene. Indeed, the PVC chain contains only very small amounts of constitutional units with allyl-linked chlorine (about 0.02 mol%, which are still referred to in the literature as the only possible reactive groups capable of forming anchored cationic centers in the chain in the presence of BCl-p but only in a polar environment As a result of previous experiments using too low concentrations of the components (2% solution of PVC in dichloromethane [isobutylene] = 0.9 mol / l. [bCIj] = 10 * ⁷ mol / l; 5. N. Gupta Kennedy, P. P., Pol., Bull., 1,253 (1979), the literature has erroneously believed that in the presence of the BClj co-initiator, non-dehydrochlorinated PVC grafting does not occur, and therefore the PVC / BClj initiated isobutylene polymerization has not been demonstrated. PVC grafting, which, however, was subjected to base dehydrochlorination prior to use, as described by Prof. Kennedy (1979)).

Recently, the use of BCl 3 has revealed that commercial, respectively. a laboratory-prepared sample of PVC or a vinyl chloride / 2-chloropropene (VC / 2-CP) copolymer is able to initiate by polymerizing isobutylene in a polar medium in the absence of protogenic substances to form a graft copolymer, e.g. polyvinyl chloride-polyisobutylene. A0 271 Θ61 and MS. A0 271 432 (Process of polymerization and copolymerization of cationic polymerizing monomers - R. Luke, L. Toman, V. Paleckova, V. Kubanek, V. Dolezal; Method of production of graft copolymers - R. Luke, L, Toman, 0. Přádová, V Pacovský, V. Kubanek, V. Dolezal).

It is generally known that the synthesis of polyisobutylene and its copolymers, e.g. with diene monomers, is exclusively carried out in a chlorinated or aliphatic solvent, e.g. methyl chloride, dichloromethane, hexane. In the absence of a co-solvent, i.e. polymerization is carried out in the block, the synthesis of isobutylene poles at C-10 ° C either does not take place, for example, when Lewis acids such as aluminum chloride (AlCl 3), titanium tetrachloride (TiCl ₄ ), titanium tetrabromide ₄ ), tin tetrachloride (SnCl ₄ ),

EN 273 801 81 vanadium chloride (VCl3) and boron trichloride (BCl3), or vice versa, violent uncontrollable to explosive polymerizations take place, for example using aluminum bromide AlBr-j as an initiator or binary initiation system, where one component is aluminum bromide such as AlBr4. TiCl 2, AlBr 1 - VCl 2 or AlBr 1 - SnCl 2 (M. Chmelir, M. Marek, 0. Wichterle, 0. Polym. Sci. Part. C, NO. 16, 833/1977); M. Chmelir, M. Marek, J. Polym. Sci. Part. C,

NO. 22, 177 (1968); Kennedy, J. P., Cationic Polymerization of Olefins; A. Critical Inventory, John Wiley &amp; Sons, A. Wiley - Interscience Publication, New York (1975); J. P.

Kennedy and Maréchal, Carbocationic Polymerization, John Wiley &amp; Sons, A. Wiley - Intersciences Publication, New York (1982)).

Due to the abrupt uncontrolled polymerization, polyisobutylene synthesis (except oil production) is not performed in the block. Only with photoinduced polymerization of isobutylene at ¢ -20 ° C can block polymerization rate of the reaction be controlled, for example by irradiation intensity or by switching the light source on or off (L. Toman, M. Marek, Makromol. Chem. 177, 3325 (1976)) No. 150,797 and No. 150,798 A method of polymerization and copolymerization of monoolefinic monomers capable of polymerizing by a cationic mechanism, in particular isobutylene - M. Marek, L. Toman, J. Pecka;

Process of copolymerization of dienes with monoolefinic monomers capable of polymerizing by a cationic mechanism, in particular with isobutylene (M. Marek, L. Toman, J. Pecka). However, photoinduced syntheses of polyisobutylenes have not found industrial use, probably because of the expensive development of a new type of polymerization photoreactor. Also the power consumption of the lighting equipment and the more expensive Lewis acid (vanadium chloride) adversely affects the economy of block polymerization under the effect of light.

It has now been found that in the presence of BCl-j at a temperature of about -70 ° C, there is no prior art initiation system in which the isobutylene polymerization in the block takes place in which the BCl-j constitutes one component of the initiator system. For example, PVC, vinyl chloride / 2-chloropropene (VC / 2-CP) or PVC- (A) isobutylene grafts are grafted and the polymerization of isobutylene is initiated by these macromolecular substances. PVC- (A) is referred to as PVC which contains about 0.15 mol% in the chain. constitutional units with allyl bonded chlorine. The course of the new block polymerization of isobutylene differs completely from known systems, such as AlBr-1, AlBr-TiCl2, but the polymerizations in the block proceed slowly, at a sufficient rate, but without undesirable overheating of the reaction mixture or explosive polymerization.

According to the invention, after mixing the powdered commercially available resp. laboratory-prepared PVC, PVC- (A) or vinyl chloride / 2-chloropropene (VC / 2-CP) copolymers with isobutylene and BCl 3 at a temperature of about -70 ° C is already visually apparent after a short time, ie about 5 min, polyisobutylene (PIB) increases on solid particles such as PVC. The volume of solid phase increases with time.

(PIB anchored on PVC), while the liquid phase (monomer) is still clear and does not increase its viscosity after several days, allowing kinetic monitoring of PVC isobutylene grafting progress in the absence of a co-solvent even at low temperatures, eg by the dilatometric method It has been shown, see Example 1, Fig. 1, that, for example, using PVC- (A) powder, which was activated by BCl-j before the reaction, after mixing with isobutylene at -78 ° C, polymerization of isobutylene is avoided. even after a very long time, for example 150 h, which is a completely unusual course of the block polymerization of isobutylene. Detected isobutylene inactivity under the same experimental conditions in initiation systems, for example protogenic substances (1 ^ 0 and HCl respectively) / BCl 3, tert-butyl chloride (t-BuCl) / BCl ₃ and CH ₃ CH = CHCH (C1) C ₅ H ₁₁ / BC1 ₃ , see Table 1 and Figure 1, demonstrates that a completely novel polymerization mechanism has been discovered by the present invention, which has not been described so far in the cationic synthesis of polyisobutylene.

SUMMARY OF THE INVENTION The present invention provides a process for the production of graft copolymers in a block comprising the step of polymerizing isobutylene at -60 to -100 ° C in the presence of an initiation system consisting of a macromolecular component of polyvinyl chloride, vinyl chloride / 2- copolymers. chlorpropene, chlorinated polyvinyl chloride,

CS 273 001 B1 of polyvinyl chloride enriched with chlorallyl structures, chlorinated polyolefins, the second component is Lcwis's boron trichloride, wherein the molar ratio of boron trichloride to isobutylene is 50 to 10 to produce products containing a chemically bound initiator component corresponding to the macromolecule used.

The polymerization systems according to the invention can advantageously be used for initiation as polymeric initiators for polymerization, respectively. copolymerization of cationic polymerizing monomers in the absence of a co-solvent or in the presence of a polar solvent such as methyl chloride, methylene chloride, ethyl chloride or mixtures thereof with non-polar solvents such as heptane, carbon tetrachloride, cyclohexane, optionally in admixture with aromatic solvents such as benzene or toluene.

As the initiator system macromolecules, it is preferred to use polychloroprene, polyvinyl chloride, vinyl chloride / 2-chloropropene copolymer, chlorinated polyvinyl chloride, polyvinyl chloride enriched with chlorallyl structures or chlorinated polyolefins, for example chlorinated polyethylene, polypropylene or hydrochlorinated polyisoprene.

An advantage of the process according to the invention is that the block polymerization of isobutylene is conducted in a non-polar environment in the absence of a co-solvent, which makes it possible to prepare, for example, high molecular weight PVC-polyisobutylene graft copolymers. This polymerization system can also be used as a highly active initiator system for the recently discovered type of cationic polymerization according to U.S. Pat. AO 271 432 and MS. 2710 271 861, with the addition of a suitable polar solvent, such as dichloromethane, methyl chloride, ethyl chloride, to the reagent system, which leads to acceleration of polymerization to produce high molecular weight types of graft copolymers having an unusually high molecular weight, i.e. up to several million. According to the invention, different types of graft copolymers can be prepared according to the embodiment, which are widely used as modifiers for the processing properties of polymer mixtures and / or polymer blends. composite.

The process for the preparation of graft copolymers according to the invention is shown in several examples. In all the examples below, the polymerizations were performed in 50 ml glass ampoules fitted with a piercing cap or in a 12 ml glass dilatometer fitted with the same capsule as the ampoules. The initiator, e.g. PVC, PVC- (A), VC / 2-CP copolymer, was mixed with the monomer at a temperature of about -70 ° C and the DCIg co-initiator was added to the system as the last component or the initiator was first mixed at this temperature. the co-initiator and the monomer added as the last component, optionally initiated by the co-initiator at room temperature, after some time the mixture was cooled to a temperature of about -70 ° C and then the monomer was added. The initiator-co-initiator interaction time is generally referred to in the examples as activation time. The polymerizations were carried out under dry conditions under nitrogen. Drying the ampoule, respectively. a dilatometer, nitrogen, isobutylene has been described previously (L. Toman, M. Marek, Makromol. Chem. 177, 3325 (1976)). BCl 3 (FLUKA) was purified by double condensation. The initiators were dried under stirring in ampoules or in a dilatometer under vacuum with occasional flushing with dry nitrogen for several hours. The molecular weights of the products were determined by gel permeation chromatography (GPC) in tetrahydrofuran solution (THF). Polystyrene standards were used to easily compare the molecular weights of the synthesis products. Molecular weights were subtracted from the peaks of the GPC curves, and these values are therefore apparent relative to polystyrene.

Example 1

Polyvinyl chloride- (A) ((PVC- (A)) powder of apparent M - / 160,000 was activated in a dilatometer with boron trichloride at room temperature for 48 h. The dilatometer was then cooled to -78 ° C and condensed with stirring isobutylene to give a mixture containing 0.6 g PVC- (A), 10 ml isobutylene and 4.6.10 mol SClj. The grafting of PVC- (A) isobutylene was monitored at -78 ° C for 150 h. The reaction was quenched by the addition of methanol and the entire dilatometer content was dissolved in tetrahydrofuran

CS 273 801 B1 4 (THF). After evaporation of THF and volatiles on the rotary evaporator, the rubbery product was dried in a vacuum oven at 40 ° C for 48 h. The dilatometric record demonstrates that the polymerization of isobutylene was carried out for a period of time without kinetic termination.

In the absence of PVC- (A) under the same experimental conditions (-78 ° C) at the same concentration of BCl-j (4.6.10 ^-3 mole) and isobutylene volume (10 ml), comparative dilatometric measurements showed no contraction of isobutylene for 150 ha no polymer was found after evaporation of the volatiles. Comparative measurements are shown in Figure 1 (β). Also, under the same experimental conditions, no bulk contraction was observed for the t-BuCl / BCl, / isobuty-3 J-linen system (t-BuCl = 0.6 g, BCl 3 = 4.6.10 mol, isobutylene - 10 mL) for The polymer was not found in the system as shown in the dilatometric record in Fig. 1 (0).

Example 2

VC / 2-CP powder copolymer of apparent molecular weight M < 6060,000 was activated with BCl 3 for 8 h at room temperature. The initiator system was then cooled to -78 ° C and mixed with the monomer at this temperature to form a mixture containing: 30 ml of isobutylene, 1 g of VC / 2-CP copolymers and 6.8. ^-3 mole of BCl 3. Over 3 minutes on VC / 2-CP copolymers, PIBs began to grow and solid particles increased in volume over time. This reacting mixture was maintained at a temperature of about -70 ° C for 48 h. THF was then added to the system and the product was dissolved at room temperature. After evaporation of THF and volatiles first on a rotary evaporator and later in a vacuum oven, a rubbery product having a molecular weight of Μλ? 3,000,000 was obtained with a total conversion of 25%.

Example 3

PVC- (A) powder of M? / 160 000 was activated with BCl? For 24 h at room temperature. The initiator system was then cooled to -78 ° C and mixed with the monomer at this temperature to form a mixture containing: 30 ml isobutylene, 1 g PVC- (A) and 6.1. 10 ^-3 mol of BCl 2. Over 3 minutes on PVC- (A) particles, PIBs began to grow and the reaction system was maintained at a temperature of about -70 ° C for 48 hours. THF was added to the mixture and the product was dissolved at room temperature. Evaporation of THF and volatiles gave a rubbery product having a molecular weight Μλ / 2,000,000 with a total conversion of 30%.

Example 4 ‘Commercial PVC powder of λ / 170,000 was mixed at -78 ° C

a) with BCl 3 and after 10 minutes isobutylene was condensed into the system; or

b) PVC was first mixed with monomer and BCl 3 was added as the last component.

Mixing of both a) and b) resulted in a mixture containing: 25 ml of isobutylene,

6.3. 10 mole of BCl ³ and 1.3 g of PVC. Within 5 minutes, PIBs began to grow on the PVC particles, while the liquid phase (monomer) was clear for several hours and did not change the viscosity. After three days at about -70 ° C, the product with grafted PIB agglomerates on PVC particles was isolated from the system at a conversion of 200% calculated to PVC.

Example 5

The isobutylene grafting of PVC was carried out as in Example 4. After three hours After mixing the PVC reactants with BCl 3 and isobutylene at -7B ° C, 35 ml of dichloromethane, respectively, was slowly added to the system. 40 ml. In both cases, the addition of a polar solvent accelerated the polymerization reaction and after a further 3 hours at -78 ° C a rubbery product having a molecular weight Mn / 2,000,000 was recovered from the system at a total conversion of 38%.

CS 273 801 Bl

Example 6

The grafting of the VC / 2-CP copolymer and PVC- (A) isobutylene was carried out according to Example 4,

After 48 hours, the reaction was terminated as described in Example 2 and the isolated rubber products had a molecular weight of about 2,000,000 at a total conversion / at 25%.

Example 7

The grafting of the VC / 2-CP copolymer with isobutylene was carried out according to Example 4. After 48 hours, dichloromethane according to Example 5 was added to the reaction system and after three hours the reaction was terminated as described in Example 2. The rubbery products had 45% conversion. «2 000 000

Table 1

Comparison of nonsreactivity of isobutylene in the presence of Lewis acid boric chloride in a non-polar environment, ie in a block at about -70 ° C using various initiators such as H ₂ O, HCl, t-BuCl and CH ₃ CH = CHCH (Cl) C ₅ H _n

[initiator] concentration [BClj] concentration (mol / 1x10 ² ) time (h) conversion (%) literature (mol / 1x10 ² ) - 12.4 48 - Kennedy - 35.8 1680 trace of polymer Kennedy ^H 2 ^D 47.8 12.40 48 - Kennedy - 22.0 48 - - 28.4 168 trace of polymer HCl 2B, 4 28.4 72; 150 - t-BuCl 2B, 4 28.4 48 - t-BuCl 45.0 33.3 168 trace of polymer C ₉ H ₁₇ Cl 10.0 25.1 168 trace of polymer

SUBJECT OF THE INVENTION

Claims (4)

Process for the production of graft copolymers of isobutylene, characterized in that the block polymerizations are carried out at a temperature of -60 to -100 ° C in the presence of an initiation system consisting of a macromolecular component containing chlorine atoms attached to secondary and / or tertiary carbons , optionally activated adjacent to the double bond, and the second component is a Lewis boric chloride acid, wherein the molar ratio of boron trichloride to isobutylene is 50 to 10 ^-5 , to produce products containing a chemically coupled initiator component corresponding to the macromolecular substance used. 2. Process according to claim 1, characterized in that a polar and / or polar solvent mixture is added to the isobutylene block polymerization system and the reaction mixture thus formed is advantageously used as an initiation system for the polymerization and copolymerization of known cationic polymerization monomers. 3. Process for the production of graft copolymers according to claim 1, characterized in that polychloroprene, polyvinyl chloride, yinyl chloride / 2-chloropropene chlorinated polyvinyl chloride, polyvinyl chloride, polyvinyl chloride and polyvinyl chloride are preferably used as macromolecules. CS 273 801 B1 6 chloride enriched with chloralyl structures or chlorinated polyolefins, for example chlorinated polyethylene, polypropylene or hydrochlorinated polyisoprene. 4. Process according to claim 1, characterized in that chlorine solvents such as methyl chloride, dichloromethane, ethyl chloride or mixtures thereof with non-polar solvents such as heptane, carbon tetrachloride, optionally in admixture with aromatic solvents such as benzene, toluene, are used as the polar halogen solvent. .