CN1966540A

CN1966540A - Method for controlling phenylethene/butadiene block copolymer PB chain 1,2- structural content for hydrogenation

Info

Publication number: CN1966540A
Application number: CN 200510032416
Authority: CN
Inventors: 韩丙勇; 邬智勇; 李望明; 夏金魁; 周立新; 梁红文
Original assignee: Baling Petrochemical Co Ltd
Current assignee: China Petrochemical Corp
Priority date: 2005-11-19
Filing date: 2005-11-19
Publication date: 2007-05-23
Anticipated expiration: 2025-11-19
Also published as: CN100497421C

Abstract

The invention provides a control method for 1, 2-level structure contents in styrene/butadiene block copolymer PB chain, which are used for hydrogenation. The structure regulator system is composed of two polar modifiers, and used to regulate the microstructure of polybutadiene. The regulation system has high efficiency and low consumption, and is not sensitive to temperature. The stability control of Bv content can be realized in the temperature-changing polymerization process.

Description

A kind of control hydrogenation styrene/butadiene block copolymer PB chain 1, the method for 2-structural content

Technical field

The present invention relates to a kind of control hydrogenation styrene/butadiene block copolymer PB chain 1, the method for 2-structural content.

Background technology

Divinyl is initiator with the organolithium, and hydrocarbon compound is that solvent carries out anionoid polymerization, can control Microstructure of Polybutadiene as structure regulator by polar reagent, makes multiple product to adapt to different demands.As: industrialized medium vinyl polybutadiene (MVPB), high vinyl polybutadiene (HVPB), three kinds of rubber of randomly solution polymerized butadiene-styrene rubber with low (S-SBR) contain vinyl (with respect to polyhutadiene) respectively, and promptly 1,2-structure (Bv), be 35%～55%, greater than 70% and 25%～70%, and the S-EB-S thermoplastic elastomer requires the mid-block polyhutadiene B of SBS must contain vinyl (1, the 2-structure) between 35%～55%, to guarantee becoming elastic performance behind the hydrogenation.Therefore, in the homopolymer and multipolymer of divinyl anionic polymerisation, contents of ethylene is a very important index of control one of product performance.

Be initiator with organolithium RLi, hydro carbons is in the butadiene homopolymerization or copolyreaction of solvent, usually utilize one or more polar Lewis base properties-correcting agent, be additive or structure regulator, to the homopolymerization product or the copolymerization product PB chain 1 of divinyl, 2-architecture content Bv controls.The Bv value increases with the molar concentration rate of [conditioning agent]/[RLi], and reduces with the increase of the temperature of reaction under the same ratio.This point has had bibliographical information (T.A.Antkowiak, A.E.Oberster, A.F.Halasa andD.P.Tate, J.Polym.Sci., A-1,10,1319; 1972).

Adopt a kind of polar additive, wait to synthesize S-SBR or SBS,, also have many pieces of documents to make reports to control the wherein contents of ethylene of polyhutadiene B as tetrahydrofuran (THF) (THF) or diglyme (2G), as Heish, H.L., J.Polym.Sci., A3,163,1965; United States Patent (USP) U.S.P.3,496,154,1970; United States Patent (USP) U.S.P.3,506,631,1970; McGrath, J.E.ed., " Anionic Polymerization Kinetics Mechanism and Synthesis ", and ACS Symp.Series 166, Washington D.C.1981, p.389; Xu Ruiqing, Dong Ruxiu, Golden Customs Thailand, Beijing Chemical Engineering College's journal, 1,116,1982; Lu Yi, Xu Ruiqing, Golden Customs Thailand, chemical industry technology, 3,1,1982; Dong Ruxiu, Golden Customs Thailand, chemical industry progress, 1,32,1987; Zhang Xingying, Golden Customs Thailand, China Synthetic Rubber Industry, 6,391,1991.

The method that adopts the mixture of two or more polar additive (Lewis base) to regulate Bv content in the polymerizing butadiene product, as United States Patent (USP) U.S.P.4,022,959, May 10,1977; United States Patent (USP) U.S.P.4,230,841, Oct.28,1980; Chinese patent ZL 92114800.3.The report that Chinese patent ZL 92114800.3 is more detailed use the conditioning agent system of two or more opposed polarity Lewis base, the fit system that comprises strong/strong, strong/weak, weak/low-pole Lewis base, the concentration of earlier fixing a kind of Lewis base, the proportioning rice that changes another kind of Lewis base and organolithium concentration is again controlled 1 in the polyhutadiene, 2-structure.Above-mentioned binary conditioning agent method can reduce polyhutadiene Bv content to regulating the susceptibility of agent content, and promptly conditioning agent content is smaller to the Bv content influence within the specific limits.

In the industrial production, the negative ion living polymerization adopts approximate adiabatic process often, so polymerization temperature is the alternating temperature process, usually between 50 ℃～100 ℃.When adopting polar reagent to be structure regulator, temperature increases Bv content and will reduce, and changes bigger.SEBS is by contents of ethylene is prepared at 30%～55% SBS hydrogenation.Wherein synthetic general the employing as the THF isopolarity of SBS regulated reagent, and its consumption is quite big, and polymeric reaction temperature is also very big to the influence of its regulating power.The Bv content distribution is inhomogeneous on institute's synthetic polymer chain like this, influences the performance of SEBS behind the hydrogenation, as product transparency etc.So (Hall James E, Schulz Donald N.EP98 977A1,1984) appear in existing temperature-resistant at present polarity adjustment reagent.

Summary of the invention

Purpose of the present invention, be, consumption lower at existing polar modifier efficient big, to adjusting function passivation under temperature sensitive, the high temperature etc., can not stablize control polyhutadiene anionic polymerization homopolymer and copolymer p R chain 1,2-structure (1, the 2-structure) defective of content, develop new structure and regulate reagent system, reach the stable control of Bv content in the alternating temperature polymerization process.

Adopt two kinds of polar modifiers to form the structure regulator system, the microtexture of polyhutadiene is regulated.Consisting of of this conditioning agent system: 1. a class amine polar modifier, its structure can be expressed as N=0-2 wherein; R ₁, R ₂And R ₃For containing the alkyl group of 1 to 4 carbon, and the three can be identical, also can be different.Typical reagent such as the pentamethyl-diethylenetriamine (PMDETA) regulated, at this moment, R ₁, R ₂And R ₃Be all methyl, n=1.2. another kind of polar reagent can be the organic compound that contains Sauerstoffatom, as ether, tetrahydrofuran (THF) (THF), dioxane etc.The consumption of amine conditioning agent and the mol ratio of initiator amount are: 10%～100%, be preferably 20%～50%; The consumption of polar reagent such as THF etc. and the mol ratio of initiator amount are: 100%～1500%, be preferably 200%～1000%.

Industrial, anionic polymerization is generally approximate adiabatic process, and polymerization temperature variations is bigger, under these circumstances, prepares the SBS of medium contents of ethylene, and the contents of ethylene product uniformly that distributes on polybutadiene segments relatively, and its method is as follows:

With the organolithium three block SBSs or star-like (SB) that reinforced or reinforced link coupled anionic polymerization method then of two steps of three steps of initiator prepares medium contents of ethylene _nR, polymerization temperature are 50 ℃～90 ℃, and polymerization reaction time is 60 minutes～120 minutes.Polymerization single polymerization monomer is vinylbenzene, divinyl, and the consumption of styrene monomer is 20%～50% of a total monomer weight, is preferably 30%～45%, and monomeric concentration expressed in percentage by weight is 6～20% in the polymeric solution, is preferably 10%～15%.

Above-mentioned used organic lithium initiator is lithium alkylide, phenyl lithium, benzyl lithium, allyl group lithium; The initiator add-on is 0.2mmol/ _{100 gram monomers}～2mmol/ _{100 gram monomers}

The polymerization solvent for use is anionic polymerization alkane, naphthenic hydrocarbon, toluene, benzene or their mixture commonly used in the prior art, and alkane mainly is hexanaphthene, hexane etc.

Use conventional nuclear magnetic resonance nmr or infrared spectra IR to 1 of sample, the 2-structural content is analyzed.

Test-results shows: when the present invention adopts novel polar Lewis base conditioning agent system, temperature fluctuates in a big way, can determine the homopolymer or the copolymer p B chain 1 of divinyl, 2-structural content (1, the 2-structure) content Bv, under comparatively high temps (＞70 ℃), novel polar modifier still has regulating effect preferably simultaneously, product B v value (50 ℃～90 ℃) in the range of reaction temperature than broad changes little, and industrial operation is controlled easily; Can recently regulate Bv value scope according to modifier concentration/spike concentration mole, satisfy the different requirements of variant production to the Bv value, conditioning agent of the present invention is water-soluble, separate with the polymer solvent system easily, at the control dienite with cinnamic multipolymer industrial goods quality and reduce cost, all has realistic meaning.

Embodiment

Enumerate some embodiments of the present invention below, so as to further specifying its characteristics, but scope of the present invention should not be so limited.

Embodiment 1

Adopt the 250ml three-necked bottle as reaction vessel.Pipette the 100ml hexanaphthene with transfer pipet, accurately draw the 6g divinyl, and add PMDETA and THF, its add-on can see Table 1.The single lithium initiator 0.4ml that adds 0.734mol/L concentration, polymerization time 1.5h.Polymerization finishes the back and uses the methyl alcohol stopped reaction, precipitates with the methyl alcohol of solution amount more than 5 times then, makes polymkeric substance and separated from solvent, and dry back characterizes polymkeric substance with gel liquid chromatography (GPC), nuclear-magnetism means of testing such as (NMR).Following table is a polymerization temperature, and polar reagent is to the influence of microtexture Bv content, wherein R ₁Represent the mol ratio of PMDETA and organolithium spike, R ₂Represent the mol ratio of THF and spike.

Polyhutadiene Bv content under table 1 different condition

R ₂	Bv，％
	Bv，％						R ₁＝0.1			R ₁＝0.3
	50℃	70℃	Difference	50℃	70℃	Difference	R ₁＝0.1			R ₁＝0.3
	50℃	70℃	Difference	50℃	70℃	Difference	0	36.8	30.5	6.3	42.3	36.9	5.4
5	37.6	33.4	4.2	44.8	42.3	2.5	0	36.8	30.5	6.3	42.3	36.9	5.4
5	37.6	33.4	4.2	44.8	42.3	2.5	10	37.9	33.5	4.4	45.0	42.6	2.4
15	38.3	34.6	3.7	45.3	43.2	2.1	10	37.9	33.5	4.4	45.0	42.6	2.4

As can be seen from the table, when two kinds of reagent use simultaneously, reduced effectively that Yin Wendu raises and the variation of the Bv content that causes.

Embodiment 2

Add the 3500ml solvent in the 5L reactor, and add 63 gram styrene monomer, 54mmol THF, 0.84mmol PMEDTA and 4.2mmoln-BuLi, polymerization temperature is 50 ℃～70 ℃.Add 294 gram divinyl behind the 30min and carry out polymerization, polymerization temperature is 50 ℃～90 ℃, reaction times 30min～60min.At last, add 63 other gram vinylbenzene and carry out polymerization.The polymkeric substance that takes a morsel is by GPC, H ¹-NMR characterizes, and recording molecular weight is 100,000, molecular weight distribution 1.1, and polyhutadiene PB chain 1, the 2-structural content is 30%, styrene content is 30% in the polymkeric substance.

Polymer fluid is fed hydrogen stop, add an amount of metallocene-titanium catalyst then, the maintenance hydrogen pressure is 1MPa～2MPa, carries out hydrogenation 1 hour～3 hours.Product is through the water vapor desolventizing, and drying under reduced pressure.Iodimetry,iodometry records degree of hydrogenation greater than 98%, and performance test shows: tensile strength is that 29.9MPa, elongation at break are 564%, are permanently deformed to 40%.

Embodiment 3

Add the 3500ml solvent in the 5L reactor, and add 58 gram styrene monomer, 41mmol THF, 0.64mmol PMEDTA and 1.6mmoln-BuLi, polymerization temperature is 50 ℃～70 ℃.Add 234 gram divinyl behind the 30min and carry out polymerization, polymerization temperature is 50 ℃～90 ℃, reaction times 30min～60min.At last, add 57 other gram vinylbenzene and carry out polymerization.The polymkeric substance that takes a morsel is by GPC, H ¹-NMR characterizes, and recording molecular weight is 220,000, molecular weight distribution 1.1, and polyhutadiene PB chain 1, the 2-structural content is 30%, polystyrene content is 33% in the polymkeric substance.

Polymer fluid is fed hydrogen stop, add an amount of metallocene-titanium catalyst then, the maintenance hydrogen pressure is 1MPa～2MPa, carries out hydrogenation 1 hour～3 hours.Product is through the water vapor desolventizing, and drying under reduced pressure.Iodimetry,iodometry records degree of hydrogenation greater than 98%, and performance test shows: tensile strength is that 9MPa, elongation at break are 711%, are permanently deformed to 120%.

Claims

1, a kind of control hydrogenation styrene/butadiene block copolymer PB chain 1, the method of 2-structural content, it is characterized in that: in the preparation process of styrene/butadiene block copolymer, adopt two kinds of polar modifiers to form the structure regulator system, microtexture to polyhutadiene is regulated, consisting of of this conditioning agent system: a class is the amine polar modifier, and its structure can be expressed as N=0-2 wherein; R ₁, R ₂And R ₃For containing the alkyl group of 1 to 4 carbon, and the three can be identical, also can be different; Another kind of is that polar reagent can be the organic compound that contains Sauerstoffatom; The consumption of amine polar modifier and the mol ratio of initiator amount are: 10%～100%; The consumption of polar reagent and the mol ratio of initiator amount are: 100%～1500%.

2, method according to claim 1 is characterized in that the amine polar modifier is a pentamethyl-diethylenetriamine, and polar reagent is a tetrahydrofuran (THF).

3, method according to claim 1 is characterized in that the consumption of amine polar modifier and the mol ratio of initiator amount are 20%～50%, and the consumption of polar reagent and the mol ratio of initiator amount are: 200%～1000%.