Cov Khoom Siv Xab Npum Hlau Stabilizers hauv PVC Ua Lawv Lub Luag Haujlwm thiab Mechanism

Polyvinyl chloride (PVC) tau txais kev qhuas rau nws qhov kev hloov pauv tau yooj yim, kev siv nyiaj tsim nyog, thiab kev hloov pauv tau rau ntau yam khoom kawg - los ntawm cov ntaub ntawv siv hauv kev tsim kho mus rau cov khoom siv kho mob thiab cov khoom siv rau cov neeg siv khoom. Txawm li cas los xij, cov khoom siv dav dav no muaj qhov tsis zoo: kev tsis ruaj khov ntawm qhov kub thiab txias. Thaum raug rau qhov kub siab (160–200 ° C) uas xav tau rau kev rho tawm, kev txhaj tshuaj molding, lossis calendering, PVC dhau los ntawm cov txheej txheem dehydrochlorination puas tsuaj. Cov tshuaj tiv thaiv no tso tawm hydrochloric acid (HCl), ib qho catalyst uas ua rau muaj kev sib txuas lus ntawm tus kheej, ua rau cov khoom puas tsuaj los ntawm kev hloov pauv, kev tawg, thiab kev poob ntawm lub zog kho tshuab. Txhawm rau txo qhov teeb meem no thiab qhib PVC lub peev xwm tag nrho, cov khoom siv cua sov yog cov khoom ntxiv uas tsis tuaj yeem sib tham tau. Ntawm cov no, Cov Hlau Xab Npum Stabilizers sawv tawm ua qhov kev daws teeb meem tseem ceeb, muaj nqis rau lawv qhov ua tau zoo, kev sib xws, thiab kev siv dav. Hauv cov blog no, peb yuav nkag mus rau hauv lub luag haujlwm thiab cov txheej txheem ntawm Cov Hlau Xab Npum Stabilizers hauv PVC ua, ci lub teeb rau cov piv txwv tseem ceeb xws li Zinc stearate PVC formulations, thiab tshawb nrhiav lawv cov ntawv thov tiag tiag thoob plaws ntau yam kev lag luam.

Ua ntej, cia peb piav qhia meej txog dab tsiCov Khoom Siv Xab Npum Hlauyog. Ntawm lawv lub hauv paus, cov stabilizers no yog cov organic metallic compounds tsim los ntawm cov tshuaj tiv thaiv ntawm fatty acids (xws li stearic, lauric, lossis oleic acid) nrog cov hlau oxides lossis hydroxides. Cov "xab npum" tshwm sim muaj cov hlau cation - feem ntau los ntawm pawg 2 (alkaline earth hlau xws li calcium, barium, lossis magnesium) lossis 12 (zinc, cadmium) ntawm lub rooj periodic - txuas nrog cov roj fatty acid anion ntev. Cov qauv tshuaj lom neeg tshwj xeeb no yog qhov ua rau lawv lub luag haujlwm ob hauv PVC stabilization: scavenging HCl thiab hloov cov chlorine atoms labile hauv PVC polymer saw. Tsis zoo li inorganic stabilizers, Hlau Xab npum Stabilizers yog lipophilic, txhais tau tias lawv sib xyaw seamlessly nrog PVC thiab lwm yam organic additives (xws li plasticizers), xyuas kom meej tias muaj kev ua tau zoo thoob plaws hauv cov khoom siv. Lawv qhov sib xws nrog ob qho tib si rigid thiab flexible PVC formulations ntxiv cement lawv cov xwm txheej ua qhov kev xaiv mus-rau rau cov chaw tsim khoom.

Lub tshuab ua haujlwm ntawm Cov Khoom Siv Xab Npum Hlau yog ib qho txheej txheem ntau kauj ruam uas tsom mus rau cov hauv paus ua rau PVC puas tsuaj. Yuav kom nkag siab txog nws, peb yuav tsum xub rov hais dua vim li cas PVC thiaj puas tsuaj los ntawm cua sov. PVC cov saw hlau muaj "qhov tsis zoo" - cov chlorine atoms uas tsis ruaj khov txuas nrog cov carbon tertiary lossis nyob ib sab ntawm cov bonds ob npaug. Cov qhov tsis zoo no yog cov ntsiab lus pib rau dehydrochlorination thaum cua sov. Thaum HCl raug tso tawm, nws ua rau muaj kev tshem tawm ntau cov HCl molecules, tsim cov bonds ob npaug raws cov saw polymer. Cov bonds ob npaug no nqus lub teeb, ua rau cov khoom siv tig daj, txiv kab ntxwv, lossis txawm tias dub, thaum cov qauv saw hlau tawg txo qhov muaj zog tensile thiab kev ywj pheej.

 

 

Cov Khoom Siv Ua Kom Xab Npum Hlau cuam tshuam rau hauv cov txheej txheem no hauv ob txoj kev tseem ceeb. Ua ntej, lawv ua haujlwm ua HCl scavengers (tseem hu ua acid acceptors). Cov hlau cation hauv xab npum reacts nrog HCl los tsim cov hlau chloride ruaj khov thiab cov roj fatty acid. Piv txwv li, hauv Zinc stearate PVC systems, zinc stearate reacts nrog HCl los tsim zinc chloride thiab stearic acid. Los ntawm kev neutralizing HCl, lub stabilizer nres qhov autocatalytic chain reaction, tiv thaiv kev puas tsuaj ntxiv. Qhov thib ob, ntau cov Khoom Siv Ua Kom Xab Npum Hlau - tshwj xeeb tshaj yog cov uas muaj zinc lossis cadmium - dhau los ntawm kev hloov pauv, hloov cov chlorine atoms labile hauv PVC saw nrog cov roj acid anion. Qhov no tsim cov ester txuas ruaj khov, tshem tawm qhov tsis zoo uas pib ua kom puas tsuaj thiab khaws cia cov polymer lub cev ruaj khov. Qhov kev ua ob npaug no - acid scavenging thiab defect capping - ua rau Cov Khoom Siv Ua Kom Xab Npum Hlau muaj txiaj ntsig zoo ntawm kev tiv thaiv kev hloov pauv thawj zaug thiab tswj kev ruaj khov thermal ntev.

Nws yog ib qho tseem ceeb uas yuav tsum nco ntsoov tias tsis muaj ib qho tshuaj ntxuav tes ua los ntawm hlau uas zoo meej rau txhua daim ntawv thov. Hloov chaw, cov chaw tsim khoom feem ntau siv cov tshuaj ntxuav tes sib xyaw ua ke ntawm ntau hom tshuaj ntxuav tes los ua kom zoo dua. Piv txwv li, cov tshuaj ntxuav tes uas muaj zinc (xws liZinc stearate) zoo heev ntawm kev khaws xim thaum ntxov, teb sai rau cov chlorine atoms uas tsis ruaj khov thiab tiv thaiv kev daj. Txawm li cas los xij, zinc chloride—ib qho khoom seem ntawm lawv cov kev ua haujlwm tshem tawm cov kua qaub—yog Lewis acid me me uas tuaj yeem txhawb kev puas tsuaj ntawm qhov kub siab lossis lub sijhawm ua haujlwm ntev (ib qho xwm txheej hu ua "zinc hlawv"). Txhawm rau tawm tsam qhov no, zinc xab npum feem ntau sib xyaw nrog calcium lossis barium xab npum. Calcium thiab barium xab npum tsis muaj txiaj ntsig zoo ntawm kev khaws xim thaum ntxov tab sis yog cov tshuaj HCl zoo dua, neutralizing zinc chloride thiab lwm yam khoom seem acidic. Qhov sib xyaw no tsim kom muaj kev sib npaug: zinc ua kom muaj xim pib ci, thaum calcium/barium muab kev ruaj khov thermal ntev. Piv txwv li, Zinc stearate PVC formulations feem ntau suav nrog calcium stearate los txo qhov zinc hlawv thiab ntev lub sijhawm ua cov khoom.

Yuav kom nkag siab zoo dua txog ntau yam ntawm Cov Khoom Siv Xab Npum Hlau thiab lawv cov ntawv thov, cia peb tshuaj xyuas cov hom feem ntau, lawv cov khoom, thiab kev siv feem ntau hauv kev ua PVC. Lub rooj hauv qab no qhia txog cov piv txwv tseem ceeb, suav nrog Zinc stearate, thiab lawv lub luag haujlwm hauv PVC tawv thiab yoog tau:

 

 

Raws li lub rooj qhia, Zinc stearate PVC daim ntawv thov dav dav ob qho tib si khov kho thiab yoog raws, ua tsaug rau nws qhov kev hloov pauv thiab kev ua tau zoo thaum ntxov xim. Hauv cov yeeb yaj kiab PVC yoog raws rau kev ntim khoom noj, piv txwv li, Zinc stearate yog sib xyaw nrog calcium stearate kom ntseeg tau tias cov yeeb yaj kiab tseem meej thiab ruaj khov thaum lub sijhawm extrusion, thaum ua raws li cov cai kev nyab xeeb khoom noj. Hauv cov qhov rai PVC khov kho, Zinc stearate pab tswj cov xim dawb ci ntawm cov profile, txawm tias thaum ua tiav ntawm qhov kub siab, thiab ua haujlwm nrog barium stearate los tiv thaiv kev puas tsuaj mus sij hawm ntev.

 

 

Cia peb kawm txog cov xwm txheej tshwj xeeb ntawm kev siv cov khoom siv los piav qhia txog cov khoom siv uas ua rau cov hlau ruaj khov, suav nrog Zinc stearate, ua rau cov khoom siv PVC ua haujlwm tau zoo li cas. Pib nrog cov khoom siv PVC ruaj khov: cov kav dej thiab cov khoom siv yog cov khoom siv PVC ruaj khov tshaj plaws, thiab lawv xav tau cov khoom ruaj khov uas tuaj yeem tiv taus qhov kub thiab txias thiab ua kom ruaj khov mus ntev hauv cov chaw ib puag ncig hnyav (piv txwv li, hauv av, raug dej). Lub tshuab ruaj khov rau cov kav dej PVC suav nrog kev sib xyaw ntawm calcium stearate (tshuaj ntxuav cov kua qaub), Zinc stearate (khaws xim thaum ntxov), thiab barium stearate (khaws tau thermal mus ntev). Qhov kev sib xyaw no ua kom cov kav dej tsis hloov xim thaum lub sijhawm extrusion, tswj lawv cov qauv kom ruaj khov hauv qab kev nyuaj siab, thiab tiv taus kev puas tsuaj los ntawm cov av noo thiab qhov kub thiab txias hloov pauv. Yog tsis muaj lub tshuab ruaj khov no, cov kav dej PVC yuav tawg thiab tawg dhau sijhawm, ua tsis tau raws li cov qauv kev lag luam rau kev nyab xeeb thiab lub neej ntev.

Cov ntawv thov PVC uas yooj ywm, uas vam khom cov yas kom ua tiav qhov yooj ywm, nthuav tawm cov teeb meem tshwj xeeb rau cov stabilizers - lawv yuav tsum sib xws nrog cov yas thiab tsis txhob tsiv mus rau qhov chaw ntawm cov khoom. Zinc stearate zoo tshaj plaws ntawm no, vim nws cov saw hlau fatty acid sib xws nrog cov yas zoo li dioctyl phthalate (DOP) thiab diisononyl phthalate (DINP). Hauv cov hluav taws xob PVC cable rwb thaiv tsev yooj ywm, piv txwv li, kev sib xyaw ntawm Zinc stearate thiab calcium stearate ua kom cov rwb thaiv tsev tseem yoog tau, tiv taus kev puas tsuaj thermal thaum lub sijhawm extrusion, thiab tswj cov khoom hluav taws xob rwb thaiv tsev dhau sijhawm. Qhov no yog qhov tseem ceeb rau cov cables siv hauv cov chaw lag luam lossis cov tsev, qhov twg qhov kub siab (los ntawm hluav taws xob tam sim no lossis cov xwm txheej ib puag ncig) tuaj yeem ua rau PVC puas tsuaj, ua rau luv luv lossis muaj kev pheej hmoo hluav taws. Lwm daim ntawv thov PVC yooj ywm tseem ceeb yog pem teb - pem teb vinyl vam khom Cov Xab Npum Hlau Stabilizers kom tswj tau nws cov xim sib xws, yooj ywm, thiab tiv taus kev hnav thiab rhuav. Zinc stearate, tshwj xeeb, pab tiv thaiv kev daj ntawm cov pem teb xim kaj, ua kom nws khaws nws qhov kev nyiam zoo nkauj rau ntau xyoo.

PVC kho mob yog lwm qhov chaw uas Cov Khoom Siv Xab Npum Hlau Ua Lub Luag Haujlwm Tseem Ceeb, nrog rau cov kev cai nruj rau kev tsis muaj tshuaj lom thiab biocompatibility. Ntawm no, cov txheej txheem stabilizer feem ntau yog raws li calcium thiab zinc xab npum (suav nrog Zinc stearate) vim lawv cov tshuaj lom tsawg, hloov cov khoom siv stabilizer qub, cov khoom siv phom sij xws li txhuas lossis cadmium. Cov yeeb nkab PVC kho mob (siv rau hauv cov kab IV, catheters, thiab cov khoom siv dialysis) xav tau cov stabilizers uas tsis leach rau hauv cov kua dej hauv lub cev thiab tuaj yeem tiv taus kev ua kom tsis muaj zog. Zinc stearate, sib xyaw nrog magnesium stearate, muab qhov ruaj khov thermal tsim nyog thaum lub sijhawm ua thiab ua kom tsis muaj zog, thaum ua kom cov yeeb nkab tseem yoog tau thiab meej. Kev sib xyaw ua ke no ua tau raws li cov qauv nruj ntawm cov koom haum tswj hwm xws li FDA thiab EU's REACH, ua rau nws yog qhov kev xaiv zoo rau kev siv kho mob.

Thaum xaiv lub tshuab ua kom ruaj khov rau cov khoom siv PVC, cov chaw tsim khoom yuav tsum xav txog ntau yam tseem ceeb. Ua ntej, hom PVC (rigid vs. flexible) qhia txog kev sib raug zoo ntawm cov khoom siv stabilizer nrog cov plasticizers - cov khoom siv flexible xav tau cov khoom siv stabilizer xws li Zinc stearate uas sib xyaw zoo nrog cov khoom siv plasticizers, thaum cov khoom siv rigid tuaj yeem siv ntau hom xab npum hlau. Qhov thib ob, cov xwm txheej ua haujlwm (kub, lub sijhawm nyob) cuam tshuam rau kev ua haujlwm ntawm cov khoom siv stabilizer: cov txheej txheem kub siab (piv txwv li, extrusion ntawm cov kav dej tuab) xav tau cov khoom siv stabilizer nrog kev ruaj khov thermal ntev, zoo li barium stearate sib xyaw. Qhov thib peb, qhov xav tau ntawm cov khoom kawg (xim, lom, tiv taus huab cua) yog qhov tseem ceeb - cov khoom noj lossis kev siv kho mob xav tau cov khoom siv stabilizer tsis muaj tshuaj lom (calcium / zinc sib xyaw), thaum cov ntawv thov sab nraum zoov xav tau cov khoom siv stabilizer uas tiv taus UV degradation (feem ntau sib xyaw nrog UV absorbers). Thaum kawg, tus nqi yog qhov yuav tsum xav txog: calcium stearate yog qhov kev xaiv pheej yig tshaj plaws, thaum zinc thiab barium xab npum kim dua me ntsis tab sis muab kev ua tau zoo dua hauv thaj chaw tshwj xeeb.

Saib mus tom ntej, yav tom ntej ntawm Cov Khoom Siv Xab Npum Hlau hauv kev ua PVC yog tsim los ntawm ob qho tseem ceeb: kev ruaj khov thiab kev tswj hwm kev nyuaj siab. Tsoomfwv thoob ntiaj teb tab tom tawm tsam cov tshuaj lom neeg ruaj khov (xws li cov hlau lead thiab cadmium), tsav kev xav tau rau lwm yam tsis muaj tshuaj lom xws li calcium-zinc blends, suav nrog Zinc stearate PVC formulations. Tsis tas li ntawd, kev thawb rau cov yas ruaj khov dua yog cov thawj coj tsim cov khoom siv bio-based Metal Soap Stabilizers - piv txwv li, stearic acid los ntawm cov khoom siv rov ua dua tshiab xws li roj xibtes lossis roj taum pauv - txo cov pa roj carbon ntawm PVC tsim. Kev tsim kho tshiab hauv cov thev naus laus zis stabilizer kuj tseem tsom mus rau kev txhim kho kev ua tau zoo: cov khoom sib xyaw tshiab ntawm cov xab npum hlau nrog cov khoom sib xyaw (xws li epoxy compounds lossis phosphites) tab tom txhim kho kev ruaj khov thermal, txo kev tsiv teb tsaws chaw hauv PVC yooj ywm, thiab txuas ntxiv lub neej kev pabcuam ntawm cov khoom kawg.

Cov Khoom Siv Xab Npum Hlau yog qhov tseem ceeb rau kev ua PVC, daws qhov tsis ruaj khov ntawm cov polymer los ntawm lawv lub luag haujlwm ob yam li HCl scavengers thiab cov neeg sawv cev rau qhov tsis zoo. Lawv qhov kev hloov pauv tau yooj yim - los ntawm cov kav dej PVC tawv mus rau cov rwb thaiv tsev cable yooj ywm thiab cov raj kho mob - los ntawm lawv qhov sib xws nrog PVC thiab lwm yam khoom ntxiv, nrog rau lub peev xwm los kho cov khoom sib xyaw rau cov ntawv thov tshwj xeeb. Zinc stearate, tshwj xeeb, sawv tawm ua tus neeg ua si tseem ceeb hauv cov kab ke no, muab cov xim zoo heev thaum ntxov thiab sib xws nrog ob qho tib si tawv thiab yooj ywm. Raws li kev lag luam PVC txuas ntxiv qhov tseem ceeb rau kev ruaj khov thiab kev nyab xeeb, Cov Khoom Siv Xab Npum Hlau (tshwj xeeb tshaj yog cov calcium-zinc sib xyaw tsis muaj tshuaj lom) yuav nyob twj ywm rau pem hauv ntej, ua rau muaj kev tsim cov khoom lag luam PVC zoo, ruaj khov uas ua tau raws li qhov xav tau ntawm cov lag luam niaj hnub thiab cov cai. Kev nkag siab txog lawv cov txheej txheem ntawm kev ua haujlwm thiab cov kev cai tshwj xeeb ntawm daim ntawv thov yog qhov tseem ceeb rau cov tuam txhab tsim khoom uas tab tom nrhiav kev qhib tag nrho lub peev xwm ntawm PVC thaum ua kom ntseeg tau tias cov khoom ua tau zoo thiab ua raws li.