Cov Cuab Yeej Sib Txawv Loj Kawg ntawm PA6 thiab PA66 rau Thermal Barrier Applications Yog Twg?

Cov chaw nyob thiab kev ncua: Vim li cas PA66 muaj kev tiv thaiv kheat zoo dua

Cov chaw nyob tshiab: Nylon 66 muaj kab ntsug sib xws thiab kab ntsug ntau dua

Qhov yooj yim hauv cheeb tsheb ntawm PA66 tuaj yeem txheeb xyuas los ntawm lub tsev neeg no nws li cas. Thaum hexamethylenediamine sib puag nrog adipic acid nyob rau hauv kev tsim kho, ob qho ntawd yog ib lub ntsiab lus muaj khoom siv thawj, lawv tsim tau ib lub polymer backbone uas tas li ib txoj kab xwm. Qhov kev arranged no pab tau rau cov hydrogen bond meej dua nyob rau hauv cov amide group ntawm lub tsev neeg kom compared to what we see in PA6. Nws tsim qhov difference tshwj tsis nyob rau hauv kev tiv thaiv kom sov. Qhov melting point ntawm PA66 yog li 260 degrees Celsius, uas yog li 40 degrees ntau dua PA6 ua ntej nws npaj mus rhaub nyob rau 220C. Cov kev sim hauv lab kuj tso cai kom qhov structure no tseem nyob ib siab dua thaum teb chaws nce, yog li qhov khoom yuav tsim nyj dav dua thaum nws raug exposure rau qhov sov ntau.

Crystallinity thiab Hydrogen Bond Density: Quantifying PA66's Thermal Stability Advantage

PA66 txo 50–60% ntawm kev muaj crystallinity—ntsim dua PA6 uas tshwm sim 20–30%—vim muaj kev sib xyuas molecular nyob ncig siab dua.

• Densité hydrogen bond , tsim kev sib sau ua ke ntau dua ntawm sab hauv ntawm molecul
• Zoo li cas, rau siab dua thiab tsis muaj kev cuam tshwv mus txog 240°C , tiv thaiv kev hloov form mus txog 240°C
• Zoo li cas, kev sib ntsaws ntau dua (347 kJ/mol kom rau 295 kJ/mol ntawm PA6), pab ntxiv kev tiv thaiv kev puav tswj hluav taws

Raws theem Polymer Science Journal (2023), PA66 zoo li cas, 85% ntawm nws kev ntsaws hniav nyob rau saum tog vuab ceev nyob rau 180°C—30 lub ntaub pheej yig ntau dua PA6. Kev txo crystallinity no yog tseem ceeb rau thermal barrier uas raug kev ntxhov ntxhua ntau hnub.

Sauv ntsuas kev sib txawv hluv qis: Qhov ua kom ncuv, HDT, thiab kev tso hluv nyob deb ntawm PA66

PA66 Qhov ua kom ncuv (260–265°C) vs PA6 (220–225°C): Kev txheeb xyuas rau kev tswj hluv

PA66 muaj txoj laj hnyav ntawm 260 mus rau 265 degrees Celsius, uas tso nws nyob ib qhov chaw zoo dua PA6 uas hnyav ntawm 220 mus rau 225 degrees. Qhov sib txawv 40 degrees no muaj txiaj ntsig loj thaum siv khoom nyob rau ze pheej zis. PA66 tso kom muaj form thiab ceev tuaj li ntawm qhov kub npaum li combustion chamber thiab exhaust manifold uas feem ntau kub dhau 200 degrees. Thaum kub li no, PA yuav ncaws siab lossis ncaws ceev tas li, ua rau cov khoom yuav hwev los sis sib hwev ib txwm tsis zoo li PA66. Cov kev sim tau pom tias PA muaj feem npua 70% yuav hwev thaum nyob rau saib kub no. Yog vim li cas PA66 tsim nyog dua thaum kub? Lub molecular structure muaj cov amide group sib xws uas tsim cov hydrogen bond zoo dua thiab sau qhov polymer chain tsis txhob rov tav dav. Tus no pab tso kom muaj qhov seal zoo nkauj rau sab nraud thiab tso kom muaj electrical properties zoo. Cov neeg tsim kho tshuab nyob rau hauv tshuab mob lossis tshuab tsev khiav huv yuav tsum xav meej meej txog qhov sib txawv no, vim tias tiv thaiv kev phom sij los ntawm kub yog qhov tseemceeb heev rau kev nyob zoo thiab kev nyob meej nyob rau ntau yam kev siv.

Txoj cai uas kuaj xyuas tiam ntawm ntu ntawm teeb meem (HDT) thiab kev nyiaj ib ncig nyiaj siab nyob rau saum npoo

Txoj cai uas kuaj xyuas tiam ntawm ntu ntawm teeb meem (HDT) kuaj xyuas txog kev nyiaj ib ncig nyiaj siab nyob rau hauv teeb meem—nyob rau qhov chaw tseem ceeb ntawm kev tshwm sim ntawm kev tiam. PA66 muaj HDT ntawm 200–220°C nyob rau 1.82 MPa, zoo dua PA6 los ntawm 20–30°C. Qhov tso tseg no pib mus rau hauv kev nyiaj ib ncig nyiaj siab dhau plua pluas lub sijhawm nyob rau hauv qhov chaw nyob heev:

PA66's crystalline structure txhim kho tiam ntawm chain mobility, txhim kho kev tiv thaiv rau qhov kub dua—tus nqi tseem ceeb nyob rau hauv cov khoom siv rau hauv qab ntawm lub taub hau ntawm lub tshuab nres tsheb uas tiv thaiv kub ntau tshaj 5,000 teev.

Glass-Fiber Reinforced PA66-GF30: Lub tswv yim rau kev tiv thaiv kub zoo tagnrho

Yuav li cas 30% Glass Fiber pab PA66 zoo dua hauv kev tiv thaiv khib thiab kev tiv thaiv rau kub

Thaum cov khaubncaws tsim khoom ntxig ib cheeb meej ntawm 30% ntawm paib thiab ntxig rau hauv PA66, lawv tau txais ib qho khoom siv tshuab kis tshaj plaws. Cov paib no tsim ib qho kev pheej hmliav hauv nruab ntawm khoom siv tshuab uas txo qhov loj ntawm khoom siv tshuab thaum nws raug ntsuab ntau, suav ntau heev txog 60% kom nrog rau PA66 tshaiv. Qhov no txhais tau hais tias cov khoom siv tshuab nyob ib qho chaw zoo ib txwm yog tias muaj kev hlo li cas los xij. Ib qho kev tshwm sim tshiab yog tias cov paib no pab faib tawm qhov tshav kub, yog li tsis tas yuav txhob muaj kev cuam tshwv lossis cov kab ntses leeg leeg tuaj nyob rau hauv kev hlo tshav kub uas peb pom nyob hauv ntau qhov chaw tsim khoom. Tab sis qhov tseem ceeb tshaj plaws yog qhov sib txawv ntawm qhov tshav kub uas PA66 nqus tau. PA66 nqus paib tuaj yeem nyob ib neeg ntau dua li 70 degrees Celsius ua ntej nws hlo li, uas pab rau cov khoom siv tshuab ua haujlwm nyob deb ntawm qhov tshav kub uas PA66 tshaiv thauj nqe tsis pub hlo. Vim tias qhov khoom siv tshuab no tso tseg kev hlo tawm thaum nws muaj nqi, nws tso siab tias nws muaj qhov chaw thiab ceev npaum li 180°C rau tshaj plaws ob txoj lub sijhawm. Qhov no ua rau nws zoo tagnrho rau cov kev siv uas qhov chaw nyob ib txwm yog ib yam tseem ceeb tshaj plaws rau kev saib xyuas tshav kub.

PA66-GF30 nyob rau hauv kev siv nyob ze kab ntsug ntawm lub rooj saub: Tsis meej ntau txog kev tso caij kom sov tshwm sim

Qhov chaw nyiag uar li cas ntawm hauv qab rooj tsho kom muaj kev cim siab rau cov khoom siv PA66-GF30. Cov khoom zoo li rooj tsho kom kuav tshaib thiab rooj tsho huv tshav kub feem ntau nyob ib si saum 220 degrees Celsius thaum twb tso kom meej nkhaus. Yog hais txog yam xe EV, cov rooj tsho battery uas tsim los ntawm PA66-GF30 tuaj yeem txo tshav kub dhau mus rau cov khoom siv sib xyaw nrog peb lub zog ntau tshaj li 40% dua li lwm yam khoom siv nyob hauv zaj. Ke v caij dab neeg thov tau tias cov khoom no yuav tsis muaj kev puas tsuaj ntawm kev ntxuav thiab ntxuav dav dav – xws li 150,000 miles. Ib qhov tseem ceeb ntxiv yog nws tsis ua rau hmov dej. Txawv li lwm yam khoom siv, PA66-GF30 tsis rub dej thiab tsis tshua muaj kev phom sij lossis muaj kev puas tsuaj rau kev tso dej. Tom qab siv ntau xyoo nyob hauv txhua hom chaw, tus neeg tsim khoom tau pab nkaum siab rau PA66-GF30 raws li tus khoom yuav tsum muaj rau kev tso tshav kub.

Kev Cuam Tshwm ntawm Kev Sib Txuas thiab Kev Sib Txuas ntawm Kev Ntxuav Ntsha: Qhov chaw PA66 txuag dua PA6

Yog tias PA66 haus hluv txias li ntawm PA6 (Polymer Degradation Study, 2023) feeb kub dua rau ob npaug, ces nws yooj yim dua rau kev siv hauv qhov chaw uas muaj kev txiav txim siab hluv thiab kub. Ob hom nylon no yuav tsum tau haus hluv txias, tab sis PA6 haus ntau heev thaum li cas los xij, yog li nws hla thiab nyiav siab thaum hluv txias hlo tawg. Tam sim no, puas yog dab tsi tuaj yeem? Thaum ob hom no tau dhau qhov kub thiab hluv txias tshaj tshuj, tag nrho cov cuab yeej no tsim ib qho chaw uas muaj zog tso caij ntau dua, uas tshwm sim cov kab ntsug ncig tas tas. Tab sis PA66 muaj kev txiav txim siab sib txawv vim tias nws tus molecular structure tsis txaus siab thiab muaj cov hydrogen bond nyob sab hauv ntau dua. Qhov kev txiav txim siab no pab tiv thaiv hluv txias kom tsis tau mus, yog li nws tsis hla lossis nyiav siab thaum kub thiab hluv txias hlo tawg. Cov kev caij rau txhim khoj kuj tseem ceeb dua. Tom qab dhau 1,000 zaug kub thiab hluv txias nyob rau 150 degrees Celsius, PA66 tsis pub tshem tawm li 80% ntawm nws tensile strength, tab sis PA6 tsuas muaj 65%. Qhov sib txawv no yog ib qhov loj rau cov khoom siv hauv qhov chaw uas muaj kub thiab hluv txias hlo tawg tshaj tshuj. Qhov kev tiv thaiv hluv txias uas muaj nyob hauv PA66 pab rau cov neeg tsim kho kom paub tias lawv khoom tsis tas yuav tsum raug phom tes los ntawm qhov chaw uas muaj hluv txias thiab kub.