Aliphatic polyamides ntawm ntau cov qauv tau ua lag luam, uas PA6, PA66, PA46, PA11 thiab PA12 yog qhov tseem ceeb tshaj plaws.Oxidative degradation nyob rau hauv PA nyob ntawm qhov degree ntawm crystallinity thiab qhov ceev ntawm amorphous theem.Raws li cov txheej txheem ib txwm muaj, aliphatic polyamides ruaj khov nrog me me ntawm cov ntsev tooj liab (txog 50 ppm) ua ke nrog halogen ions (xws li iodine thiab bromide ions).Qhov ua tau zoo ntawm qhov system stabilizer yog qhov xav tsis thoob vim tias tooj liab ions raug suav hais tias yog kev pabcuam kev laus hauv polyolefins.Lub mechanism ntawm stabilizing nyhuv ntawm tooj liab / halogen composite system tseem tab tom kawm.
Aromatic amines yog cov tshuaj stabilizers uas nce LTTS, tab sis thaum siv hauv PA, lawv tuaj yeem ua rau tsis muaj xim ntawm cov polymers.Phenol antioxidants tuaj yeem txhim kho thawj xim tom qab polycondensation kom ruaj khov aliphatic polyamide.Feem ntau, cov tshuaj antioxidant no ntxiv ua ntej cov tshuaj tiv thaiv polycondensation raug txiav.
Cov lus hauv qab no piv cov khoom ntawm cov stabilizers sib txawv siv rau aliphatic polyamide.
| AO system | Qhov zoo | Tsis muaj zog |
| Tooj ntsev / iodide | Zoo heev nyob rau hauv tsawg concentrations Thaum qhov kub thiab txias siab tshaj 150 ° C, nws muaj txiaj ntsig zoo rau LTTS ntawm polymer | Tsis zoo dispersibility hauv polymers Leaching tshwm sim yooj yim thaum sib cuag nrog dej lossis dej / cov kuab tshuaj Tej zaum yuav ua rau discoloration |
| Cov tshuaj tsw qab amines | Nws muaj txiaj ntsig zoo rau LTTS ntawm polymers | Nyob rau hauv high concentrations kev hloov xim |
| Phenols | Nws muaj txiaj ntsig zoo rau LTTS ntawm polymers Kev ua tau zoo xim Muaj peev xwm ntxiv tau thaum lub sij hawm txheej txheem concentration Tsis muaj kev tawm tsam tshwm sim nrog lwm cov polymers thaum sib xyaw |
Ntawm qhov kub ntawm kev laus (piv txwv li saum 150 ° C), tooj liab / iodide stabilizer tshuab qhia tau zoo tshaj plaws.Txawm li cas los xij, ntawm qhov kub thiab txias qis, phenolic antioxidants ib leeg lossis ua ke nrog phosphites tuaj yeem ua haujlwm zoo dua.Lwm qhov txiaj ntsig ntawm kev siv phenolic antioxidants yog tias lawv khaws cov xim tseem ceeb ntawm polypolymers kom txog thaum tshav kub kub zoo dua tooj liab ntsev stabilizers.
Lub discoloration ntawm lub polymer tom qab tshav kub laus tsis txo nyob rau hauv parallel nrog nws txhua yam khoom.Discoloration tuaj yeem tshwm sim txawm tias lub sijhawm luv luv ntawm lub hnub nyoog, tab sis lub zog tensile elastic thiab elongation ntawm cov polymer yuav tsis cuam tshuam txog tom qab.
Lub cev loj ntawm cov ntaub ntawv piav qhia txog ntau daim ntawv thov ntawm iav fiber reinforced polyamides nyob rau hauv kev lag luam tsheb, xws li cov cav tov, radiator caps thiab grilles, brakes thiab fais fab steering accumulators, lub tes tsho valve, log tsheb, cua nres contactors thiab hoods.Phenolic antioxidants, ib leeg lossis ua ke nrog phosphite, yog qhov zoo tshaj plaws stabilizers rau GFR PA66.
Lub hauv paus mis ntawm phenol + phosphite ua ke yog 1098 + 168, uas tuaj yeem siv rau qhov kub thiab txias tsis zoo, thiab cov xim extrusion zoo dua.Txawm li cas los xij, rau cov tshuab polyamide xws li iav fiber reinforcement, kev ua haujlwm kub yog siab dua (ze li 300 ° C), 168 kub decomposition tsis ua hauj lwm, nyob rau lub sij hawm no, peb feem ntau siv 1098 + S9228 xws li kev sib xyaw ua ke ntawm qhov kub thiab txias, uas kuj yog. feem ntau siv cov mis hauv high-temperature nylon.
Tom qab cov txiaj ntsig tau zoo, nws pom tau tias 1098 + S9228 tseem muaj chaw rau kev txhim kho xim ntawm cov nylon kub kub, thiab Sarex Chemical launched upgraded khoom SARAFOS 2628P5 (phosphorus-based auxiliary resistance) thiab SARANOX PA2624 (hindered pheneol thiab kev sib xyaw ua ke) muaj kev ua tau zoo dua hauv nylon high-temperature yellowing, thiab cov ntaub ntawv ntsuam xyuas muaj xws li hauv qab no:
PA66, 270 ° C ntau extrusion thiab kub ci kev sim
| 0.1% 1098 + 0.2% 9228 | 8.32 ib | 15.5 ib | 21.11 Nws | 33.71 ib |
| 0.1% 109810.2% 2628P5 | 3.85 ib | 10.88 Nws | 17.02 Nws | 21.16 Nws |
| ■ 3% PA2624 | -3.25 | 1.87 ib | 4.94 ib | 12.21 Nws |
Cov ntaub ntawv saum toj no tau txiav txim los ntawm Sarex Chemical Laboratory
Piv nrog rau tib qhov sib ntxiv ntawm SARAFOS 2628P5 thiab S9228, cov xim ntawm ntau yam extrusion thiab 120 ° C thaum tshav kub kub cia rau 12h muaj kev ua tau zoo, thiab hydrolysis tsis kam ntawm cov khoom nws tus kheej kuj zoo dua li ntawm S9228, uas muaj daim ntawv thov zoo. kev cia siab hauv PA hloov kho.
Thaum muaj cov kev xav tau ntau dua rau cov xim thawj zaug, nws raug pom zoo kom ntxiv SARANOX PA2624, ntxiv rau daim ntawv hmoov, peb kuj tuaj yeem muab cov neeg siv khoom nrog PA antioxidant masterbatches thiab cov cab kuj-dawb antioxidant hais, uas yooj yim rau ntxiv thiab tawg, thiab pab. lub rooj cob qhia ntau lawm kom tsis muaj plua plav.
| PA66, ntau yam extrusion ntawm 270 ° C | 0.1% 1098 + 0.2% 9228 | 0.1% 1098 + 0.2% 2628P5 | 0.3% PA 2624 |
| 1 extrusion |  |  |  |
| 3 extrusion |  |  |  |
| 5 extrusion |  |  |  |
| Ci ntawm 120 ° C, 12h
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Cov ntaub ntawv saum toj no tau txiav txim los ntawm Sarex Chemical Laboratory
Post lub sij hawm: Nov-14-2022