CN1580081A - Multi-arm star-type thermoplastic elastomer initiating system - Google Patents

Abstract

The invention refers to a new multi-armed starlike thermoplastic elastomer solicitation system and is applied to the high molecular compound produced by the carbon-carbon dangling bond cationic polymerization reaction. The new solicitation system is composed of the initiator, coinitiator and nucleophilic reagent. It is used to initiate the vinyl monomer for the homopolymerization, block copolymerization, star polymerization and graft copolymerization. The raw material of the solicitation system is cheap and familiar chemical reagents. The product has large molecule weight and good performance and can provide the industrialization of the active cationic polymerizations of olefin compounds with favorable conditions.

Description

Initiation system of multi-arm star-shaped thermoplastic elastomer

Technical Field

The invention relates to a novel initiation system which is used for a macromolecular compound obtained by active cationic polymerization reaction of carbon-carbon unsaturated bonds, in particular to a novel initiation system of an active cationic polymerization multi-arm star-shaped thermoplastic elastomer consisting of organic halide, a coinitiator and a nucleophilic reagent.

Background

In the living cationic polymerization, various side reactions are liable to occur in the polymerization reaction due to the high activity of the carbenium ion, so that the realization of the living cationic polymerization is very difficult, and in recent years, the research on the initiation system thereof has realized the living cationic polymerization of different systems.

To date, mainly the following active cationic polymerization systems have been found and reported:

organic peroxide/Lewis acid as initiating system, CH₃Cl or CH₂Cl₂In the case of a solvent, isobutene is initiated at low temperature;

2, 4, 4-trimethyl-2-chloropentane (TMPCl)/TiCl₄To initiate the system, CH₃Cl and methylcyclohexane are used as solvents, and styrene is initiated at low temperature in the presence of N, N-dimethylacetamide;

U.S. p5451647 provides an active cationic polymerization with an organic compound alcohol, ether, ester, or organic halide as initiator, a lewis acid as co-initiator, in the presence of 2, 6-di-tert-butylpyridine to produce a homopolymer, copolymer, or block copolymer;

EP0725095 provides a reactive cationic polymerization system for initiating the polymerization of vinyl monomers in the presence of an initiator, a co-initiator and pyridine or a derivative thereof.

At present, different initiation systems are generally adopted when different monomers are polymerized, and widely applicable initiation systems are lacked.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a stable and novel active cation initiation system for initiating vinyl monomers to perform homopolymerization, block copolymerization, star polymerization and graft copolymerization.

The object of the invention can be achieved by the following measures: the initiating system of the active cation is composed of

(1) Initiator, a compound having the general formula and derivatives thereof

Wherein R is₂、R₃Each represents a hydrogen atom, R₁、R₂、R₃Each represents C₁～C₈Straight or branched alkyl, R₂Represents a five-membered, six-membered saturated or unsaturated ring, R₁And R₂Together with the linking carbon atom to form a five-membered, six-membered saturated or unsaturated ring, X represents halogen;

(2) co-initiator lewis acid: SnCl₄，BCl₃，TiCl₄，SbF₅，SeCl₃，ZnCl₂，FeCl₃，VCl₄，AlRnCl_n-3Wherein R represents C₁～C₈N represents an integer of 0 to 3;

(3) nucleophile lewis base: piperidine or its derivative, aliphatic amine and aromatic amine.

The concentration of the initiator is 1 mol/L-10^-5mol/L, the adding amount of the initiator is determined by the molecular weight of the polymerization product, and the preferred initiator is benzene tetrachloride.

The concentration of the coinitiator is 10 mol/L-10^-4The amount of co-initiator added is determined by the amount of initiator added, preferably the co-initiator is TiCl₄。

The concentration of the nucleophilic reagent is 1 mol/L-10^-5mol/L, the adding amount of the nucleophilic reagent is determined by the water content of the system and the adding amount of the initiator, and the preferable nucleophilic reagent is piperidine.

The mixed solvent is CH₃Cl or CH₂Cl₂Mixing with any one of cyclohexane, n-hexane, and methylcyclohexane at a volume ratio of 40: 60, preferably CH₃And (3) a mixed solvent of Cl and cyclohexane of 40: 60 (V: V), wherein the addition amount of the mixed solvent is 1-50 times of the volume number of the polymerized monomers.

The terminating agent is hydrochloric acid solution of methanol or ethanol.

The organic compound whose monomer mainly contains vinyl can be aliphatic, aromatic, ether, conjugated diene, etc., such as isobutylene, styrene, indene, vinyl ether, isoprene, etc.

The active cation polymerization process comprises the steps of sequentially adding a mixed solvent, an initiator, a coinitiator Lewis acid and a nucleophilic reagent Lewis base into a dry and pure reaction container under the normal pressure and the protection of dry nitrogen at the reaction temperature of 0-90 ℃, firstly aging for 10-60 minutes, adding a vinyl monomer, adding a terminator after reacting for 1 hour, pouring the terminated solution into a large amount of solution, precipitating a product, and filtering or drying.

In the synthesis process, the solvent is added firstly, and then the polymerization is carried out according to a certain feeding sequence. The charging sequence is that mixed solvent, initiator, co-initiator and nucleophilic reagent are added simultaneously, or the initiator, co-initiator and nucleophilic reagent are added first and aged for 10-60 minutes, then monomer is added for polymerization reaction, and the molecular weight of the obtained product is large.

The attached drawing of the initiation system of active cation (using benzene tetrachloride initiation as an example)

Chain initiation:

1. formation of carbonium ions:

compared with the prior art, the invention has the following advantages:

1. the invention provides a stable and relatively consistent initiating system for initiating vinyl monomers to carry out homopolymerization, block copolymerization, star polymerization and graft copolymerization.

2. Using benzenetetracarboxylic acid chloride, TiCl₄Initiation system for piperidine and the resulting polymer molecular weightIs large.

3. The invention utilizes common chemical reagents as an initiator, a coinitiator, a nucleophilic reagent and a mixed solvent, and provides favorable conditions for industrialization of the synthesis method.

Detailed Description

Example 1: living cationic polymerization of polyisobutenes

Adding CH into a dry reaction container under the protection of dry nitrogen at the normal pressure and the reaction temperature of-70 to-90 DEG C₂Cl₂1L of a mixed solvent prepared from cyclohexane in a volume ratio of 40: 60 is added in sequence with 1X 10^-3Benzene tetrachloride in mol/L, TiCl in 0.04mol/L₄，1.2×10^-3Aging for 15 min with piperidine of mol/L, adding 1.14mol/L isobutene, reacting for 1 hr, adding 5% hydrochloric acid in methanol to terminate, pouring the solution into ethanol solution, precipitating, filtering and drying.

The polyisobutylene product had a number average molecular weight of 155000 and a molecular weight distribution of 1.84.

Example 2: multi-arm star-shaped polyisobutylene-polystyrene block thermoplastic elastomer

Adding 1L of mixed solvent and 0L into a dry and pure reaction container under the protection of dry nitrogen at the normal pressure and the reaction temperature of-75 to-80 ℃. 5X 10^-3mol/L benzenetetracarboxylic acid chloride, 0.02mol/L TiCl₄，1.2×10^-3Aging with mol/L piperidine for 15 min, adding isobutylene to maintain its concentration at 2.8mol/L, reacting for 1 hr, adding end capping agent 1, 1-diphenylethylene to obtain 6 × 10 concentration^-3And (3) mol/L, aging for 15 minutes, adding a plastic hard segment monomer or the concentration of the plastic hard segment monomer is 0.6mol/L, continuing to react for 1 hour, adding methanol dissolved with 5% HCl into the system for stopping, pouring the solution after stopping into a large amount of ethanol solution, precipitating to separate out a product, filtering and drying.

Block thermoplastic elastomer product number average molecular weight 2.3X 10⁴The molecular weight distribution is 2.0, the glass transition temperature is 197 ℃, the tensile strength is 20MPa, the elongation is 400 percent, and the Shore hardness is 45.

The invention also claims a patent of the synthesis method of the initiating system for the active cationic polymerization of polyolefin.

Claims (6)

1. A multi-arm star-shaped thermoplastic elastomer initiation system for polyolefin living cationic polymerization is characterized by comprising the following components in percentage by weight:

(1) initiator: compounds having the general formula and derivatives thereof

Wherein R is₂、R₃Each represents a hydrogen atom, R₁、R₂、R₃Each represents C₁～C₈Straight or branched alkyl, R₂Represents a five-membered, six-membered saturated or unsaturated ring, R₁And R₂Together with the linking carbon atom to form a five-membered, six-membered saturated or unsaturated ring, X represents halogen;

(2) a co-initiator lewis acid; SnCl₄，BCl₃，TiCl₄，SbF₅，SeCl₃，ZnCl₂，FeCl₃，VCl₄，AlRnCl_n-3Wherein R represents C₁～C₈N represents an integer of 0 to 3;

(3) nucleophile lewis base: piperidine or its derivatives, aliphatic amines, aromatic amines; the mol numbers of the initiator, the coinitiator and the nucleophilic reagent are respectively 1 mol/L-10^-5mol/L，10mol/L～10^-4mol/L，1mol/L～10^-5And mol/L, in the synthesisprocess, adding a solvent firstly, and then carrying out polymerization according to a certain feeding sequence.

2. The initiating system of claim 1, wherein: the initiator is benzene tetrachloride.

3. The initiating system of claim 1, wherein: the co-initiator is titanium tetrachloride.

4. The initiating system of claim 1, wherein: the nucleophile is piperidine.

5. The initiating system of claim 1, wherein: the concentration of the initiator is 1 mol/L-10^-5mol/L, the concentration of the coinitiator is 10 mol/L-10^-4mol/L, the concentration of the nucleophilic reagent is 1 mol/L-10^-5mol/L。

6. The initiating system of claim 1, wherein: in the polymerization method, the initiator, the co-initiator, the nucleophilic reagent and the monomer are added simultaneously at one time or the initiator, the co-initiator and the nucleophilic reagent are added firstly and aged for 10-60 minutes, and then the monomer is added for polymerization reaction.