PET is flame retardant method and development trend overview

Published on 2018-08-13

Get together to benzene glycol of 2 formic acid ester is thermoplastic one of the mainest breed in polyester, england made public the patent of PET of the first preparation 1946, american DuPont company realized the industrialized production of PET the earliest 1953. Earlier PET is used at synthetic fibre entirely almost, arrived to go up century 80 time, PET serves as a project plastic had revolutionary progress, become afterwards nylon, polycarbonate, polyformaldehyde, get together the 5th big project after benzene aether is plastic. PET is the plastic breed with very rapid development, the crop of global PET had exceeded 76.7 million tons 2016, predict global PET crop will amount to one hundred and ten million one hundred and seventy thousand tons 2020.

PET can hold good physical performance and mechanical property inside wider temperature range, its fatigue resistance, be able to bear or endure attrition sex and ageing resistance are admirable, insulating property is outstanding, organic to great majority dissolvent and inorganic acid are stable, and manufacturing specific power consumption is low, processability is good, be used extensively at plastic bag bottle, film and synthetic fibre all the time consequently. It is plastic and OK that PET serves as a project use at the following domains, at the same time its wastage is respectively: Electronic electric equipment 26% , car 22% , mechanical 19% , appliance 10% , consumable 10% , other 13% . Because PET applies extensively at the industry such as car, electric equipment, and these industries have firm demand to material combustion and safety performance, accordingly, raising flame retardation is PET plastic one of the mainest demands. No matter regard as plastic still be fiber, the flame retardation demand of this material is higher, because this development is flame retardant,PET is making the research field with PET important material increasingly. Preparation is flame retardant the main method of PET material has 3 kinds as follows:

One, PET adds fire retardant flame retardant law

The method that adds fire retardant is the fire retardant of young member compound that joins proper sort and dosage in PET matrix, use fire retardant and base material the gas phase when combustion or agglomeration photograph are flame retardant the flame retardation that action will come to raise PET. Its advantage is a method simple, cost is inferior, can go to the lavatory to adjust neatly the flame retardation of earning PET and flame retardant level, satisfy the need of all sorts of actual application, because use a kind of more extensive method at present however. The main problem that its exist is great majority of these fire retardant of young member compound flame retardant efficiency is inferior, add a capacity big, in gift PET flame retardation while often can be opposite the treatment function of material and mechanical function produce negative effect. In addition, the chemical composition difference of these fire retardant and PET is bigger, consistence is accordingly poorer, the fire retardant in be being machined and using a process may from inside PET migratory with separate out, the exterior quality that affects product and flame retardant the endurance of the effect.

Graph 1 high temperature from cross-linking copolymerization ester flame retardant sketch map of the drop that fight frit

The compound that can make fire retardant add PET has a variety of, if 10 bromine are joined in PET,2 benzene aether can rise good flame retardant the effect. Because this fire retardant contains bromic amount,this is tall, decompose temperature is more than 350 ℃ , it is a kind of purity the bromine with tall, admirable thermal stability changes fire retardant of scent a group of things with common features. But from 20 centuries since 80 time, people discovery contains much bromine in the child heating up solution of DBDPO 2 benzene and 2 evil alkyl and much bromine 2 benzene and furan two kinds of toxicant are qualitative, among them latter is had cause cancerous effect by force, evaluate about the risk of this one problem still be in research, make multilateral home and did not adopt measure to try to restrict. Home is at present flame retardant PET manufacturer still uses DBDPO extensively to make main fire retardant.

Phosphoric acid is added in PET 3 benzene ester, phosphoric acid 3 toluene ester, phosphoric acid 3 second ester, contain bromine ester of 3 phosphoric acid make flame retardant PET, also was to use the method that adds fire retardant to undertake flame retardant. Among them what TDBPPE suits PET particularly is flame retardant, because TDBPPE contains bromine and phosphor inside same element,this is, have stew in soy sauce – phosphor synergism, and phosphor is in in PET flame retardant efficiency is extremely tall. Make with TDBPPE flame retardant when PET, can with 3 oxidation 2 antimony are used, also can use alone. Make with TDBPPE flame retardant when 30% Bo fine enhances PET, antagonism action exists between antimonial acerbity natrium and TDBPPE, the oxygen index that can lower material apparently reachs anti-flammability. For example, make with 15% TDBPPE and natrium of 5% antimonial acid flame retardant when 30% Bo fine enhances PET, the oxygen index of material is 29.4% , UL is flame retardant grade is V- 2 class, combustion time is 5.1s. But if replace the natrium of 5% antimonial acid in former recipe with the TDBPPE of 5% , criterion the oxygen index of material rises to 36.5% , anti-flammability amounts to V- 0 class, combustion time falls for 0.1s. Flame retardant to PET the oxygen index of material, the effect that adds TDBPPE is better. But as phosphoric acid ester kind add model fire retardant also has inadequacy, basically be phosphoric acid ester kind fire retardant is a liquid mostly, hear resistance is poor, volatile big, consistence is not quite good also, and fire retardant contains phosphor quantity and flame retardant effect cardinal principle becomes direct ratio. Because this development has ester of the admirable hear resistance and consistence, condensation polymerization that uses the solid high polymer that waits for an advantage to measure easily phosphoric acid,becoming phosphor to fasten fire retardant is the trend of development. The Phosgard 2XC-20 that American Monsanto company develops is not fire retardant of ester of volatile phosphoric acid one kind namely, what its use at PET is flame retardant the effect with was obtained better.

Graph 2 but high temperature the monomer of copolymerization ester function from cross-linking

What inorganic phosphor fastens fire retardant to also can be used at PET material is flame retardant, basically have red phosphorus, phosphate, get together ammonium phosphate, belong to the fire retardant that be not bittern, among them red phosphorus is a kind of better PET fire retardant, have add a capacity little, use is extensive wait for an advantage. Contain only as a result of red phosphorus flame retardant element, accordingly its fasten fire retardant efficiency than other phosphor tall, contain material of oxygen high polymer to PET especially relatively effective. But common red phosphorus sucks tide easily, give off phosphine gas, and the consistence with PET is poor, because this is general,use directly as fire retardant hard. And the active that small capsule changed red phosphorus fire retardant to reduce red phosphorus, solved consistence problem, make red phosphorus produced main effect in applying actually thereby. In reborn PET plastic in join quality mark to be the small capsule red phosphorus of 5% , add in coordination with inorganic fire retardant, result limiting oxygen index is achieved 35.5. As the development of red phosphorus fire retardant, whiteness changed the development of fire retardant of small capsule red phosphorus to overcome the color restriction that red phosphorus fire retardant uses in material, because its are had as good as colophony consistence, do not float in use process red, flame retardant efficiency tall, noxiousness is small wait for an advantage, accordingly relatively agree with ecru and flame retardant the production with PET plastic project. In addition, phosphate is in thermoplastic a kind of effective fire retardant also is in polyester. Get together among them ammonium phosphate is to develop the phosphor that rise to fasten inorganic fire retardant in recent years, because it contains phosphor to measure the tall, volume that contain nitrogen much, and have thermal stability good, water-solubility is small, flame retardant the advantage such as effect muscularity, because this received wide application in a lot of domains. But pyrolysis suffers to produce young member compound below APP high temperature, satisfy hard thermoplastic the requirement that machines below higher temperature, accordingly, use small capsule technology to undertake to APP Fu is handled wrapping in recent years, with gifting its taller thermal stability is mixed be able to bear or endure ability in swimming, regard PET project as plastic fire retardant.

What nitrogen fastens fire retardant to also can be used at PET is flame retardant, the fire retardant containing nitrogen that applies at present basically includes 3 kinds big: 3 get together salt of cyanogen amine, double cyanogen amine, guanidine and its ramification. Among them 3 get together cyanogen amine, 3 get together acid of make water of cyanogen amine cyanogen and 3 get together ester of cyanogen amine phosphoric acid is the variety that development latent capacity has most in fire retardant market. What fasten fire retardant about nitrogen is flame retardant mechanism, after thinking nitrogen fastens fire retardant be heated to decompose normally, yi Fang gives the asbestine gas such as oxide of nitrogen of ammoniac gas, nitrogen, deepness, water vapour, of asbestine gas generate and fire retardant decomposes absorption of heat to take away major quantity of heat, drop the exterior temperature of polymer greatly. The action of the flammability gas that asbestine gas removed the oxygen in attenuant air and PET be heated to decompose generation, have the presence of the fire retardant that contain nitrogen as a result of PET at the same time, return when combustion can generate with reaction of the oxygen in air carbon dioxide, water and the oxide that contain nitrogen, consuming material surface oxygen while, achieve good flame retardant the effect. The main good point that nitrogen is fire retardant is efficient and flame retardant, do not contain haloid, without corrode action to wait.

2, PET copolymerization is flame retardant law

Copolymerization is flame retardant the PET that PET is the preparation in participating in process of PET polymerization reaction as the 3rd monomer with reaction fire retardant is flame retardant composite material. Reaction fire retardant contains P, N to wait commonly flame retardant element, the existence of these elements can pass the means such as the hot degradation course that changes polymer matrix to raise the anti-flammability of polymer. When to benzene 2 formic acid and glycol synthesize PET, join in polymeric department can participate in reaction to have flame retardant and characteristic reaction at the same time the 3rd monomer, let its share the synthetic reaction of PET, make its are united in wedlock in the element advocate rise thereby on catenary flame retardant the effect. But this kind of fire retardant that already won industrial application is very few, main reason is his when containing phosphor to measure low, stability to owe beautiful, synthesis easy assemble in change etc.

Graph 3 contain ester of copolymerization of structure of 2 benzene acetylene sketch map of perpendicular combustion process

The PET that the method that uses copolymerization gets having flame retardation also weighs a structure model flame retardant the PET that the law gets. Use at flame retardant the copolymerization of PET is flame retardant there still is phenyl in monomer phosphine of oxidation of 2 carboxyl phenyl, it is a kind of extremely typical copolymerization flame retardant monomer, have exceedingly good flame retardation not only, and can make flame retardant a lot of function of PET get ameliorative. BCPPO is organic oxidation phosphine kind, thermal stability is taller, its pyrolysis temperature is in 350 ℃ above, the biggest the amount that when 650 ℃ in; of 450 ℃ above its disclose odd-come-short amounts to the temperature that decomposes rate correspondence 40% , have taller char effect. The copolymerization that accordingly BCPPO regards PET as is flame retardant monomer won’t be decomposed below aggregate temperature. In addition, BCPPO contains double luscious group, can mix with glycol to benzene copolymerization of 2 formic acid synthesizes copolymerization flame retardant PET. Because organic phosphor is flame retardant,copolymerization of elemental random ground is on macromolecule catenary, consequently of earning flame retardant PET has permanent flame retardation. What copolymerization gets is flame retardant material calls essence flame retardant material, because have special chemical structure, although do not join fire retardant,also have enough flame retardation. Essence is flame retardant high polymer has high fever stability, low combustion speed and good the ability that prevents blaze transmission, although face,also be such when quite tall thermal current.

The scientist is synthesized – Ding Er is acerbity, this is PET new-style copolymerization flame retardant the 3rd monomer. The phosphoric acid ester in DDP element structure and couplet benzene form stable cricoid structure, and be in side catenary position to have good thermal stability and fight hydrolysis sex, it and PET copolymerization hind, can raise the anti-flammability of PET, overcome flame retardant the weakness that PET Yi Shui sees, hold the treatment property with original PET, have wide applied perspective. 2- carboxyl second base phenyl second phosphoric acid also is PET when synthesis flame retardant the 3rd monomer, CEPPA belongs to ramification of second phosphoric acid, acidity is stronger, the hydroxyl on this compound and carboxyl have taller reaction active. Because CEPPA contains phosphorous element, and have taller thermal stability and oxidation stability, because this is a kind of good PET response fire retardant. Somebody uses CEPPA to serve as the 3rd monomer, former add phosphate glass synergism, pass former a PET/P-glass that copolymerization makes P-glass content is different is flame retardant material, experimental result makes clear, the accretion of P-glass can promote a system to become charcoal, in the meantime, add the addition of the quantity as P-glass, of composite material flame retardant function and function of the drop that fight frit all promote somewhat. When P-glass content achieves 1% above, LOI achieves 30% above, level of UL94 perpendicular combustion reachs V-0 level. Additional, discover through be not the research of isothermal crystallization behavior to composite material, p-glass does not have an influence almost to PET crystal structure, but the crystallization rate that can lower PET.

Graph 4 from get together the batten after content oxygen index checks and from get together content is flame retardant sketch map of the drop that fight frit

Additional, hydroxyl of double phenolic A and double phenolic F, 10- – 10 oxygen – 10 hydrogen – Fen evil phosphor – 2, when sylvite of 2 carboxylic acid also can regard 8- as PET synthesis flame retardant the 3rd monomer, somebody parts to regard the 3rd monomer as to participate in PET polymerization double phenolic A and double phenolic F in reaction, make two kinds of PET. PET of opposite Yu Chun all has the thermal stability of two kinds of PET to rise certainly, but flame retardation does not have big promotion. The LOI of double phenolic A PET only from 22% rise 25% , UL94 grade had better reach V2 level, and frit drop is severe; and double phenolic F PET slightly good, LOI is highest for 26% , and can produce not stable charcoal layer, have certain curb smoke effect. Have division researcher serves as with DHPPOK the 3rd monomer and to benzene 2 formic acid, glycol undertakes copolymerization, make so that contain the PET of ion radical group, the PET that synthesizes heterocycle of similar the department that contain phosphor at the same time serves as contrast. Through the experiment contrast discovers, PETIs-K has taller thermal stability, DHPPO-K can promote base material to form stable charcoal layer when the degradation below high temperature, be helpful for raising the flame retardation of material. Although PETPs and PETIs-K have taller LOI, but PETIs-K still is had at the same time taller from extinguish and function of the drop that fight frit. The phosphor in PETPs and PETIs-K is in in material flame retardant action kind is different, the phosphor in PETPs enters gas phase to act well when material degradation, and the phosphor in PETIs-K basically is in agglomeration is effective.

3, PET intelligence is flame retardant law

PET intelligence is flame retardant the scientist puts forward recently, the PET with flame retardant intelligence does not have distinction with common PET when processing, but when this PET is being ignited, its chemistry structure can produce change, if produce fast cross-linking application, make its fuse-element viscosity rapid steep add and quicken char, rise thereby flame retardant the double action with the drop that fight frit, if pursue,1 is shown. Typical PET intelligence is flame retardant it is to pass melt condensation polymerization to introduce in PET element catenary but from cross-linking function group, if the graph is shown 2 times, preparation hands in copolymerization ester oneself. Earning copolymerization ester can be in maintain the circumstance with original and characteristic PET to fall, implementation is flame retardant not frit drips, if pursue,3 are shown. Any traditions are not contained in PET of this kind of copolymerization at the same time flame retardant element, for green flame retardant new technology provided a kind of brand-new means.

Flame retardant to intelligence PET, the scientist still offerred additionally two sort recently model intelligence is flame retardant technology, namely ionic polymer fights frit drop and high temperature to fight frit to drip from recomposition. Compare from the chemical cross-linking photograph of cross-linking with high temperature, ionic polymer the means with reversible physics cross-linking, increase material fuse-element viscosity, realize the drop that fight frit. The scientist designed a series of ion that contain phosphor recently flame retardant monomer, of earning from get together content polyester all is shown relatively of beautiful flame retardant effect of the drop that fight frit. High temperature fights frit to drip from recomposition is introduce through be in PET element catenary but the structure of high temperature recomposition, polymer element recomposition is passed below high temperature, stimulative material becomes carbonization, implementation is flame retardant the drop that fight frit.

4, epilogue

PET of the preparation on industry is at present flame retardant material still is with adding fire retardant the law is given priority to, because,basically be flame retardant the group that the PET material of modified preparation does not transform PET manufactures technology, methodological change is quick, adjust easily. Add PET of preparation of fire retardant law flame retardant material has a variety of advantages, the synergism that passes a variety of fire retardant can raise the flame retardation of composite material effectively. But add model fire retardant is general the consistence with PET is poorer, add a capacity normally taller, meet those who cause the apparent of goods, mechanical function drop. How design fire retardant answer match a recipe, and overcome mix in all flame retardant the problem such as the consistence that modified brings and dispersive sex, below the situation that affects other performance not badly, be material to bring admirable flame retardation is current research heat, also will be henceforth PET is flame retardant the main development direction of material. Copolymerization is flame retardant modified law is relatively mature, but its have limitation, the PET material of preparation of the reaction that serves as the 3rd monomer fire retardant needs to change the technological process that PET polymerization produces, face numerous PET product, this kind flame retardant methodological general comfortable sex is poorer, cost is higher. The copolymerization with new-style development is flame retardant PET, raise its general comfortable sex, it is current PET copolymerization is flame retardant direction of a of modified composite material important research and development. The research with PET flame retardant intelligence just just arisen, but its have infinite development latent capacity.