阅读说明：本技术 一种可降解阻燃聚苯乙烯塑料及其制备方法 (Degradable flame-retardant polystyrene plastic and preparation method thereof ) 是由 邱元栏 于 2021-01-13 设计创作，主要内容包括：本发明公开一种可降解阻燃聚苯乙烯塑料及其制备方法；可降解阻燃聚苯乙烯塑料由下述组分组成：70～90质量份可降解阻燃聚苯乙烯,1～3质量份抗氧化剂,1～4质量份抗静电剂,2～5质量份抗冲击改性剂,7～10质量份增塑剂,3～8质量份热稳定剂；本发明通过在聚苯乙烯分子链上嵌段二硫代磷酸酯,使聚苯乙烯分子具有阻燃性,同时在分子链中嵌段甲基丙烯酸聚乙二醇酯,聚苯乙烯保持各种优越的性能,同时使聚苯乙烯材料具有可降解性能。(The invention discloses a degradable flame-retardant polystyrene plastic and a preparation method thereof; the degradable flame-retardant polystyrene plastic comprises the following components: 70-90 parts by mass of degradable flame-retardant polystyrene, 1-3 parts by mass of antioxidant, 1-4 parts by mass of antistatic agent, 2-5 parts by mass of impact modifier, 7-10 parts by mass of plasticizer and 3-8 parts by mass of heat stabilizer; according to the invention, the dithiophosphate is blocked on the polystyrene molecular chain, so that the polystyrene molecule has flame retardance, and meanwhile, the polyethylene glycol methacrylate is blocked in the molecular chain, so that the polystyrene keeps various excellent performances, and meanwhile, the polystyrene material has degradability.)

1. The degradable flame-retardant polystyrene plastic is characterized by comprising the following components: 70-90 parts by mass of degradable flame-retardant polystyrene, 1-3 parts by mass of antioxidant, 1-4 parts by mass of antistatic agent, 2-5 parts by mass of impact modifier, 7-10 parts by mass of plasticizer and 3-8 parts by mass of heat stabilizer, wherein the degradable flame-retardant polystyrene has a structure shown in formula (I):

in the formula, n is 23-66, m is 5-10, and p is 10-20.

2. The degradable flame-retardant polystyrene plastic of claim 1, wherein the preparation method of the degradable flame-retardant polystyrene comprises the following steps:

(1) RAFT reagent 4-cyano-4- (thiobenzoic acid) pentanoic acid and SOCl₂Macromolecular chain transfer agent for polystyrene by performing acyl chlorination reaction and then performing esterification reaction with single-terminal hydroxyl polystyrene；

(2) Taking dioxane as a solvent, azodiisobutyronitrile as an initiator, and carrying out polymerization reaction on dithiophosphate on a molecular chain of a polystyrene macromolecular chain transfer agent to obtain a polystyrene block dithiophosphate copolymer;

(3) tetrahydrofuran is used as a solvent, polyethylene glycol methacrylate is used as a monomer, azodiisobutyronitrile is used as an initiator, and a polystyrene block dithiophosphate copolymer is used as a chain transfer agent, the reaction is carried out for 1 to 3 hours at 70 to 80 ℃ under the conditions of no water, no oxygen and nitrogen protection, the reaction is stopped after the reaction is carried out, the product is quenched in liquid nitrogen, and the obtained reaction product is precipitated in a precipitator, so that the degradable flame-retardant polystyrene is obtained.

3. The degradable flame-retardant polystyrene plastic of claim 2, wherein in the step (1), the preparation method of the degradable flame-retardant polystyrene comprises the steps of reacting the single-terminal hydroxy polystyrene, 4-cyano-4- (thiobenzoic acid) valeric acid and SOCl₂In a molar ratio of 1:5: 25.

4. The degradable flame-retardant polystyrene plastic of claim 2, wherein in the step (2) of the preparation method of the degradable flame-retardant polystyrene, the structural formula of the dithiophosphate is as follows:

5. the degradable flame-retardant polystyrene plastic of claim 2, wherein in the step (2), the molar ratio of the azobisisobutyronitrile to the polystyrene macromolecular chain transfer agent to the dithiophosphate is 1:10: 100.

6. The degradable flame-retardant polystyrene plastic of claim 2, wherein in the step (3) of the preparation method of the degradable flame-retardant polystyrene, the molar ratio of the azobisisobutyronitrile to the polystyrene block dithiophosphate copolymer and the polyethylene glycol methacrylate is 1:10: 1000.

7. The degradable flame-retardant polystyrene plastic of claim 2, wherein in the step (3) of the preparation method of the degradable flame-retardant polystyrene, the molar concentration of the polyethylene glycol methacrylate in the polymerization system is 1 mol/L.

8. The degradable flame-retardant polystyrene plastic according to claim 1, wherein the antioxidant is selected from one or two of dilauryl thiodipropionate and 2, 6-di-tert-butyl-4-methylphenol; the antistatic agent is selected from one or more of polyoxyethylene stearate, polyethylene glycol methacrylic acid dimer, ethylene oxide and polyetherimide; the impact modifier is selected from acrylate copolymers; the plasticizer is selected from one or more of pentaerythritol, dibutyl sebacate and diisononyl phthalate; the heat stabilizer is selected from dibutyltin maleate or lead stearate.

9. The degradable flame-retardant polystyrene plastic according to claim 1, which is characterized by comprising the following steps:

mixing 70-90 parts by mass of degradable flame-retardant polystyrene, 1-3 parts by mass of antioxidant, 1-4 parts by mass of antistatic agent, 2-5 parts by mass of impact modifier, 7-10 parts by mass of plasticizer and 3-8 parts by mass of heat stabilizer in a high-speed mixer at normal temperature, extruding, cooling and granulating to prepare the degradable flame-retardant polystyrene plastic.

Technical Field

The invention belongs to the field of high polymer chemical synthesis, and particularly relates to degradable flame-retardant polystyrene plastic and a preparation method thereof.

Background

Polystyrene molecular chains are composed of hydrocarbon elements, are easy to combust and have no flame retardance, and a flame retardant is usually added in the preparation of polystyrene materials, for example, Chinese patent CN 103709431B discloses a polystyrene with high flame retardance and a preparation method thereof, wherein a halogen-free environment-friendly solid flame retardant and a halogen-free liquid flame retardant are compounded, and a solid-phase flame retardant is uniformly dispersed in a liquid-phase flame retardant to achieve the effect of synergistic flame retardance, so that the problem of the flame retardance of the polystyrene materials is solved, and various superior performances of the polystyrene are kept; but the obtained polystyrene has no degradable property; based on the above, the invention provides a degradable flame-retardant polystyrene plastic and a preparation method thereof.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides degradable flame-retardant polystyrene plastic and a preparation method thereof.

The invention aims to provide a degradable flame-retardant polystyrene plastic.

The invention also aims to provide a preparation method of the degradable flame-retardant polystyrene plastic.

The above purpose of the invention is realized by the following technical scheme:

the preparation method of the degradable flame-retardant polystyrene plastic comprises the following steps:

the composition is prepared from the following components in parts by weight: 70-90 parts by mass of degradable flame-retardant polystyrene, 1-3 parts by mass of antioxidant, 1-4 parts by mass of antistatic agent, 2-5 parts by mass of impact modifier, 7-10 parts by mass of plasticizer and 3-8 parts by mass of heat stabilizer are mixed in a high-speed mixer at normal temperature for extrusion, cooling and granulation, and the degradable flame-retardant polystyrene plastic is prepared.

The structural formula of the degradable flame-retardant polystyrene is shown as the following formula (I):

in the formula, n is 23-66, m is 5-10, and p is 10-20.

The preparation method of the degradable flame-retardant polystyrene comprises the following steps:

RAFT reagent 4-cyano-4- (thiobenzoic) pentanoic acid with SOCl₂And (3) carrying out acyl chlorination reaction, and then carrying out esterification reaction with single-end hydroxyl polystyrene to obtain the polystyrene macromolecular chain transfer agent.

The single-terminal hydroxy polystyrene, 4-cyano-4- (thiobenzoic acid) valeric acid and SOCl₂In a molar ratio of 1:5: 25.

2. Taking dioxane as a solvent, azodiisobutyronitrile as an initiator, and carrying out polymerization reaction on dithiophosphate on a molecular chain of a polystyrene macromolecular chain transfer agent to obtain the polystyrene block dithiophosphate copolymer.

The structural formula of the dithiophosphate is shown as follows:

the molar ratio of the azodiisobutyronitrile to the polystyrene macromolecular chain transfer agent to the dithiophosphate is 1:10: 100.

3. Tetrahydrofuran is used as a solvent, polyethylene glycol methacrylate is used as a monomer, azodiisobutyronitrile is used as an initiator, and a polystyrene block dithiophosphate copolymer is used as a chain transfer agent, the reaction is carried out for 1 to 3 hours at 70 to 80 ℃ under the conditions of no water, no oxygen and nitrogen protection, the reaction is stopped after the reaction is carried out, the product is quenched in liquid nitrogen, and the obtained reaction product is precipitated in a precipitator, so that the degradable flame-retardant polystyrene is obtained.

The molar ratio of the azodiisobutyronitrile to the polystyrene block dithiophosphate copolymer to the methacrylic acid polyethylene glycol ester is 1:10: 1000.

The molar concentration of the polyethylene glycol methacrylate in a polymerization system is 1 mol/L.

The antioxidant is selected from one or two of dilauryl thiodipropionate and 2, 6-di-tert-butyl-4-methylphenol.

The antistatic agent is selected from one or more of polyoxyethylene stearate, polyethylene glycol methacrylic acid dimer, ethylene oxide and polyetherimide.

The impact modifier is selected from acrylate copolymers.

The plasticizer is selected from one or more of pentaerythritol, dibutyl sebacate and diisononyl phthalate.

The heat stabilizer is selected from dibutyltin maleate or lead stearate.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) the invention provides a degradable flame-retardant polystyrene plastic, which is characterized in that a dithiophosphate is blocked on a polystyrene molecular chain, so that polystyrene molecules have flame retardance, and the problems that the flame retardant is added into a polystyrene base material by a physical mixing method, and the dispersing uniformity of the flame retardant is not easy to guarantee, the loss of flame-retardant components is difficult to avoid and the long-term flame retardance of products is directly influenced due to the weak bonding effect between the flame retardant molecules and the polystyrene base material are solved.

(2) By blocking polyethylene glycol methacrylate in a molecular chain, the polystyrene material has degradability while maintaining various excellent performances, thereby achieving the purpose of environmental protection.

Drawings

FIG. 1 is a nuclear magnetic hydrogen spectrum of degradable flame-retardant polystyrene.

FIG. 2 is an infrared spectrum of degradable flame-retardant polystyrene.

Detailed Description

The present invention will be described in further detail with reference to specific examples, which are not intended to limit the present invention in any manner. Reagents, methods and apparatus used in the present invention are conventional in the art unless otherwise indicated.

Example 1

4-cyano-4- (thiobenzoic acid) pentanoic acid (5mmol) was added to a 100mL branched flask equipped with a reflux condenser, 30mL of anhydrous THF was injected, and a new distillation was slowly added dropwise with stirringSOCl₂(25mmol), after the addition was complete, the mixture was refluxed for 1.5h, and SOCl was removed under reduced pressure₂And THF to give the product as a yellow oil, which was dissolved by adding a small amount of anhydrous toluene.

N₂Under protection, adding PE-OH (1mmol) into a 100mL flask with a branch mouth, injecting 30mL of anhydrous toluene, heating to 75 ℃ while stirring, adding 1mL of pyridine after the PE-OH is completely dissolved, continuously stirring for 10min, slowly dropwise adding the newly prepared yellow oily product dissolved in the toluene, stirring for 2.5h at 80 ℃ after dropwise adding is finished, pouring the product into methanol for precipitation, and drying to constant weight at 35 ℃ in vacuum after toluene/methanol dissolution/precipitation circulation is carried out twice, thus obtaining the polystyrene macromolecular chain transfer agent.

Example 2

N₂Under protection, AIBN (0.01mmol), polystyrene macromolecular chain transfer agent (0.10mmol), phosphorodithioate (10mmol) and 15ml dioxane are added into a 20ml Schlenk bottle, the Schlenk bottle is placed in a preset oil bath at 75 ℃ for polymerization reaction, the Schlenk bottle is taken out immediately after the reaction is carried out for 0.5h and is immersed in liquid nitrogen for cooling, a product is precipitated in a large amount of diethyl ether, and THF/diethyl ether dissolution/precipitation circulation is carried out twice, so that the polystyrene block phosphorodithioate copolymer is obtained.

Example 3

Dissolving polyethylene glycol methacrylate (15.0mmol), polystyrene block dithiophosphate copolymer (1.5mmol) and azobisisobutyronitrile (0.015mmol) in 15mL of tetrahydrofuran, pumping and charging nitrogen for multiple times, reacting for 2 hours at 70 ℃, putting the mixture into liquid nitrogen to quench the reaction, repeatedly precipitating for 3 times by using methanol/water as a precipitator, and drying at the temperature of 45 ℃ in vacuum to constant weight to obtain the degradable flame-retardant polystyrene with the yield of 70.5%.

Example 4

The composition is prepared from the following components in parts by weight: 70 parts by mass of degradable flame-retardant polystyrene, 4 parts by mass of dilauryl thiodipropionate, 3 parts by mass of polyoxyethylene stearate, 5 parts by mass of acrylate copolymer, 12 parts by mass of diisononyl phthalate and 6 parts by mass of dibutyltin maleate are mixed in a high-speed mixer at normal temperature for extrusion, cooling and granulation, and the degradable flame-retardant polystyrene plastic is prepared.

Example 5

The composition is prepared from the following components in parts by weight: 80 parts by mass of degradable flame-retardant polystyrene, 3 parts by mass of dilauryl thiodipropionate, 3 parts by mass of polyoxyethylene stearate, 4 parts by mass of acrylate copolymer, 5 parts by mass of diisononyl phthalate and 5 parts by mass of dibutyltin maleate are mixed in a high-speed mixer at normal temperature for extrusion, cooling and granulation, and the degradable flame-retardant polystyrene plastic is prepared.

Example 6

The composition is prepared from the following components in parts by weight: 90 parts by mass of polystyrene block dithiophosphate copolymer, 2 parts by mass of dilauryl thiodipropionate, 1 part by mass of polyoxyethylene stearate, 2 parts by mass of acrylate copolymer, 2 parts by mass of diisononyl phthalate and 3 parts by mass of dibutyltin maleate are mixed in a high-speed mixer at normal temperature for extrusion, cooling and granulation, and the degradable flame-retardant polystyrene plastic is prepared.

Comparative example 1

Before processing, polystyrene is dried for 12 hours in vacuum at 80 ℃, 100 wt% of polystyrene is added on an open type heat mixing machine with a double-roller temperature of 130 ℃, after the polystyrene is melted and coated on a roller, the polystyrene is mixed for 10min and then evenly taken out, hot pressing is carried out on a flat vulcanizing machine for 10min at 135 ℃, cold pressing is carried out for 8min at room temperature, the polystyrene is taken out, various standard sample strips are prepared on a universal sampling machine, and the flame retardant property test is carried out.

Limiting oxygen index test: the instrument is FTAII (1600) type limit oxygen index instrument of RS company in UK, test standard GB/T2406.2-2009, spline specification 100mm x 6mm x 3mm, and a group of 5-10, before test, the spline is placed in an environment with temperature 23 + -2 deg.C and humidity 50 + -5% and adjusted for more than 88 h.

UL-94 vertical burning test: the instrument is an CZF-5A horizontal vertical combustion tester of Jiangning analytical instruments factory for carrying out UL-94 vertical combustion test, the specification of the sample bar is 125mm multiplied by 13mm multiplied by 3.2mm, and the test standard is UL94ISBN 0-7629 and 0082-2. Before testing, the sample is put in an environment with the temperature of 23 +/-2 ℃ and the humidity of 50 +/-5% and is adjusted for more than 48 h.

The flame retardant performance of the degradable flame retardant polystyrene plastic is evaluated through a limit oxygen index and a UL-94 vertical combustion test, and the result is shown in Table 1.

Table 1 shows the flame retardant properties of the degradable flame retardant polystyrene plastic.

Sample (I)	Example 4	Example 5	Example 6	Comparative example 1
					LOI(％)	30.7	32.4	35.6	18.1
UL-94	V-1	V-1	V-1	N.R
					Degradation rate (%) for 6 days under the conditions of the buried test	25.6	23.4	21.0	10.2

As can be seen from Table 1, the organic micromolecules with flame retardant effect are blocked on the polystyrene polymer chain, so that the flame retardant property of the polystyrene can be obviously improved. As can be seen from the comparison of the data of the examples 4-6 and the comparative example 1, the LOI of the pure PE is only 18.1%, and when the polystyrene is modified by blocking dithiophosphate with a flame retardant effect on a polystyrene molecular chain, the LOI can reach 35.6%, so that the flame retardant property of the polystyrene is effectively improved.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.