DD289282A5 - PROCESS FOR PREPARING ALPHA, OMEGA DIHYDROXYTRIBLOCKCODIOLS - Google Patents

Abstract

The invention relates to a process for the preparation of α, α-dihydroxytriblock codiols which are applicable, for example, to the hydrophilic preparation of polyurethane materials or as non-ionogenic polymeric surfactants. The object of the invention is to provide in a simple manner novel hydrophilic-equipped a, v block codiols. The object is achieved according to the invention by the fact that a, v-tetrahydrofuran-diols having an average molar mass of 300 to 2000 g / mol and a functionality 1.8 in the ratio 1: 1 to 10: 1 are purposefully copolymerized with * Dihydroxytriblock codiole, a, v-tetrahydrofurandiol; * Stage polymerization; Grenzflaechenaktivitaet; hydrophilicity}

Description

Field of application of the invention

The invention relates to a process for the preparation of σ, ω-dihydroxytriblock codiols which are applicable, for example, to the hydrophilic finish of polyurethane materials or as nonionic polymeric surfactants.

Characteristic of the known state of the art

Since the introduction of the polyaddition principle in the practice of polymer synthesis, especially for the classes of polyurethanes and epoxy resins, the construction of polymers of α, ω-functional oligomers increasingly gaining space as a viable development direction in the field of plastics. Thus, well-defined, α, ω-functional oligomeric products of alkylene oxides, butadiene, 1,3-dioxacyclanes, introduced by alkenes, lactones and lactams products of polymer chemistry today. Functional groups include: -OH, -COOH, -NH ₂ , -halogens, as well as the C = C double bond (macromers). The oligomers can be equipped with one or with different functional groups. While at the beginning of this development direction oligomers were preferably constructed from a monomer type, soon co- and teroligomers were used, the nature of the linkage and the order of the monomer units were initially of minor importance. However, as the analysis technique progressed and the understanding of the relationships between the structure and properties of the polymers and their oligomeric precursors increased, the further development in the field of oligomer synthesis was segmented from tasks to the construction and finally determined by block copolymeric products.

Usually, copolymers and oligomers of tetrahydrofuran are synthesized by copolymerization of the respective monomers. Patents have been filed for such processes since 1981 (US Pat. No. 4,299,993). As comonomers are described, for example: propylene oxide, ethylene oxide, nitroglycidyl ether, epichlorohydrin, 1,3-dioxolane (GB-PS 2022106, GB-PS 2025995). The syntheses are started with initiators such as BF ₃ -etherate, acetic anhydride, perchloric acid, SnCl ₄ and also SO ₃ H- or CFxRySOjH-terminated resins. The aim of the copolymerization are in addition to the general property modification, in particular the formulation of defined functional groups (-OH ₁ -CH ₂ OH ₇ -OR). The processes are carried out at room temperature under an inert atmosphere. The reaction times are 7 to 16 hours. The structure of the oligomers is not uniform. In this case, preference is given to copolymers having a statistical distribution. In this way, certain properties bound to the appearance of finite segments of the particular monomer are not effective or statistically distributed over the oligomer molecule. Significant improvements are achieved when the copolymerization is carried out as a stage polymerization. The reaction is started with a monomer, led to the desired degree of polymerization and then continued with the second monomer (E.Franta et al., Makromelecular Chem., Makromolecu.'ar Symp., 13/14 (1988), 127, St. Penczek et al., Makromolecular Chem., Makromolecular Symp.3 [1986], 203). Such "living" or "quasi-living" polymerization is technically extremely difficult to hear, since the concentration of active sites, especially in the transition from one monomer to another, must not change significantly if the unwanted homopolymer formation is to be prevented , The conventional variants of the reaction of such a stage polymerization are described for example for the synthesis of polyols for use in polyurethane systems (DH-OS 2035134, GB-PS 1120223). Here, after an anionically initiated propylene oxide polymerization, a segment of ethylene oxide units is grafted on. The aim of these processes are block copolymers having hydrophilic properties and, above all, high contents of primary OH end groups in order to ensure a high reactivity of the polyols in the reaction with diisocyanates and polyisocyanates.

A similar structure is shown by tetrahydrofuran-ethylene oxide copolyols described by Y.lkeda et al. in J. Chem. Soc. Jpn. (1986), pp. 699-705. A tetrahydrofi'randiol is converted with alkoxide to the alcoholate and ethylene oxide is grafted in the manner of an anionically initiated alkylene oxide. The reaction is carried out at elevated temperature and under pressure.

Object of the invention The invention aims to provide novel hydrophilic α, ω block codiols in a simple manner. Explanation of the essence of the invention The object of the invention is hydrophilically equipped α, ω-block codiols having relative molecular weights in the range of 1500

to produce up to 3000g / mol.

The object is achieved in that α, ω-Tetrahydrofurandiole with an average molecular weight of 300 to

2000g / mol and a functionality> 1.8 in the ratio 1: 1 to 10: 1 are copolymerized with 1,3,6-trioxocane such that it is first with about one tenth to twentieth of the total amount of the 1,3,6-trioxocane mixed well at temperatures between 30 and 50 ⁰ C, by the Eimragen of 0.05 to 0.1 mol (preferably 0.028 to 0,033mol) initiator per rnol OH Gruppsn the

Block copolymer initiated within 5 to 30 minutes, then quickly added dropwise the residual monomer so

is that the current monomer concentration remains approximately constant at the reaction centers, and after 15 to 60 minutes

Alkali hydroxide solution is added to the neutral point. The inventive method avoids the competition of homopolymeric trioxocane formation, it is possible Target polymerization of trioxocane segments of defined length onto the THF strain. Particularly favorable are trioxocane / OH Ratios up to values of 5: 1. Suitable initiators are protonic or Lewis acids such as HCIO ₄ , CF ₃ SO ₃ H or SbCl ₆ . The

The process according to the invention can also be carried out in solvents such as toluene or halogenated hydrocarbons. After the readily evaporable fractions (solvent and water from the neutralization process) and a filtration have been stripped off, the a.c.-dihydroxytriblockcodiols according to the invention, which are represented by the general formula | (CH ₂ ) jO (CH ₂ ) ₂ O (CHj) _n - [(CHj) 4OJ _in - [(CH,) jO (CH,) 2OCH ₂ O] _n where _n = 1-30 and m = 1-25 are present as viscous, water-light liquids.

Depending on the composition, they are hydrophilic to water-soluble. Due to their segmentation into one

hydrophobic [(CH ₂ J ₄ O _n I-BIoCk and two hydrophilic 1 (CH ₂ I ₂ O (CHj) ₂ OCH ₂ OJn _n -BlOCkO have interface activity.) Molecular weight of the block codiols can be between 1000 and 3000g / mol and the block length ratio can be set between 1: 1 and 10: 1.

The α, ω-Dihydroxytriblockcodiole invention are miscible in any ratio with di- and poly-isocyanate and

are particularly suitable for the production of elastic polyurethanes.

embodiments example 1

40 g (0.042 mol) of tetrahydrofurandiol having a number average Ml mass of 950 g / mol are mixed with 9.9 g (0.084 mol) of 1,3,6-trioxocane (TO) and tempered with stirring to 50 ° C. Initiation of the block copolymer formation occurs with 0.354g of a 70% HCIO ₄ . The start of the reaction is a lc.nperaturanstieg 3 to 5 ⁰ C in less than 5 Minutensignalisiert. To extend the TO segments further 29.7 g (0.252 mol) of TO are added dropwise such that the

Monomer concentration in the mixture remains constant and sufficiently small. Thirty minutes after complete TO addition

is neutralized with 40% KOH solution. After all easily volatile fractions from the polymer mixture by means of

Rotation are carried out in vacuo and the polyol is separated from solid residues by filtration, you get a clear,

moderately viscous liquid with a TO / OH ratio of 4: 1.

OHZ - = 55

M _n = 1930g / mol

Hw-c = 1150mPas

F = -1.89

If, after initiation, no further addition of TO is obtained after the temperature maximum has been reached, but the termination of polymer formation by means of KOH is stopped immediately, a copolydiol having a TO / OH ratio of 1: 1 is obtained.

OHN = 95

M _n = 1200g / mol

Iso'c = 950mPas

F = 2

Example 2

The base polyol used is a tetrahydrofuran diol having a number average molecular weight of 2000 g / mol. There are 84 g (0.042 mol) of diol mixed with 9.9 g (0.042 mol) of TO tempered to 50 ⁰ C and brought analogously to Example 1 for copolymer formation. Thirty minutes after reaching the maximum temperature, a further 9.9 g (0.042 mol) of TO are added dropwise. The demolition is then carried out with 40% KOH and the workup as described above. This gives a codiol with a TO / OH ratio of 2: 1.

OHC - 44.4

M _n = 2400g / mol

F = 1.9

Example 3

For a better distribution of initiator and monomers! in the base polyol, working with solvents in dry form. It is important to ensure that a solvent / polymer ratio of 10: 1 is always respected, d. H. that in the dosage of residual TO after initiation, the required amount of solvent is introduced into the mixture. To this was added 40 g (0.042 mol) of tetrahydrofurandiol having a number average molecular weight of 950 g / mol and 9.9 g (0.084 mol) of TO in 500 g of toluene and starting with 0.354 g of a 70% strength HCIO4. A rise in temperature is not observed here because of the large amount of solvent and thus rapid removal of heat released to a small extent. After 30 minutes, a further 39.6 g (0.335 mol) of TO are added in 400 g of toluene. After stopping the copolymer formation with 40% KOH, the solvent and other volatile components are rotary evaporated on a rotary evaporator and the product is sucked through a frit. A clear, moderately viscous codiol having a TO / OH ratio of 5: 1 is obtained.

OH = 49.4

M _n = 2100g / mol

F = 1.85

Example 4

In addition to HCIO ₄ as an initiator, the system can also bring with other proton acids for copolymer formation.

There were 63g (0.042 mol) of a mixed tetrahydrofurandiol with a number average molecular weight of 1500 g / mol with 9.9 g (0.042 mol) of TO and heated to 50 ⁰ C. The copolymer formation is initiated by means of 0.249 g of CF3SO3H.

Another 19.8 g (0.1676 mol) of TO are metered in 30 minutes after reaching the maximum temperature via a dropping funnel.

Demolition and processing take place as already described. A viscous block copolyol having a TO / OH ratio is obtained

OHN = 49 M _n = 2150g / mol F = 1.88

Claims (6)

1. A process for the preparation of a ^ -Dihydroxytriblockcodiolen, characterized in that α, ω-tetrahydrofuran-diols having an average molecular weight of 300 to 2 OOOg / moi and a functionality> 1.8 in the ratio 1: 1 to 10: 1 in such a way with lAe Trioxocancopolymerisiert that they are first mixed well with about the tenth to twentieth part of the total amount of 1,3,6-trioxocane at temperatures between 30 and 5O ⁰ C, by the entry of 0.05 to 0.1 mol of a proton or Lewis acid as an initiator per mole of OH groups, the block copolymer formation is initiated within 5 to 30 minutes, then rapidly the remaining monomer is added dropwise so that the current monomer concentration at the reaction centers remains approximately constant, and after 15 to 60 minutes alkali hydroxide solution added to the neutral point becomes. 2. The method according to claim 1, characterized in that preferably α, ω-Tetrahydrofurandiole an average molecular weight of 500 to 1500 g / mol are used. 3. The method according to claim 1, characterized in that preferably 0.028 to 0.033 mol of initiator per mole of OH groups are used. 4. The method according to claim 1 and 3, characterized in that as initiator HCIO ₄ , CF ₃ SO ₃ H or SbCI ₅ , are used. 5. The method according to claim 1 to 4, characterized in that the α, ω-tetrahydrofuran-diols having an average molecular weight of 300 to 2000g / mol and a functionality> 1.8 in the ratio 1: 1 to 10: 1 with 1.3, 6-Trioxocan be copolymerized in the presence of a polar solvent. 6. The method according to claim 5, daduich characterized in that are used as the polar solvent toluene or halogenated hydrocarbons.