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