Cov Txheej Txheem thiab Hom Polyethylene Synthesis
(1) Polyethylene Uas Muaj Qhov Ceev Tsawg (LDPE)
Thaum ntxiv cov pa oxygen lossis peroxides me me ua cov khoom pib rau ethylene ntshiab, nias kom txog li 202.6 kPa, thiab cua sov kom txog li 200 ° C, ethylene polymerizes rau hauv polyethylene dawb, waxy. Txoj kev no feem ntau hu ua cov txheej txheem siab vim yog cov xwm txheej ua haujlwm. Cov polyethylene tshwm sim muaj qhov ceev ntawm 0.915–0.930 g / cm³ thiab qhov hnyav molecular xws li 15,000 txog 40,000. Nws cov qauv molecular yog branched heev thiab xoob, zoo li "ntoo zoo li", uas suav nrog nws qhov ceev tsawg, yog li lub npe polyethylene qis-density.
(2) Polyethylene Nruab Nrab-Density (MDPE)
Cov txheej txheem nruab nrab-siab suav nrog polymerizing ethylene nyob rau hauv 30–100 atmospheres siv cov hlau oxide catalysts. Cov polyethylene tshwm sim muaj qhov ceev ntawm 0.931–0.940 g / cm³. MDPE kuj tseem tuaj yeem tsim los ntawm kev sib xyaw cov polyethylene siab (HDPE) nrog LDPE lossis los ntawm kev sib xyaw ntawm ethylene nrog comonomers xws li butene, vinyl acetate, lossis acrylates.
(3) Polyethylene Uas Muaj Zog Heev (HDPE)
Nyob rau hauv qhov kub thiab txias ib txwm muaj, ethylene yog polymerized siv cov catalysts sib koom ua ke zoo heev (organometallic compounds ua los ntawm alkylaluminum thiab titanium tetrachloride). Vim yog qhov ua haujlwm catalytic siab, qhov kev sib xyaw ua ke tuaj yeem ua tiav sai sai ntawm qhov siab qis (0-10 atm) thiab qhov kub qis (60-75 ° C), yog li lub npe txheej txheem qis-siab. Cov polyethylene tshwm sim muaj cov qauv molecular tsis muaj ceg, linear, ua rau nws qhov ceev siab (0.941-0.965 g / cm³). Piv rau LDPE, HDPE ua rau muaj kev tiv thaiv cua sov zoo dua, cov khoom siv kho tshuab, thiab kev tiv thaiv kev ntxhov siab ib puag ncig.
Cov Khoom ntawm Polyethylene
Polyethylene yog ib hom yas dawb zoo li mis nyuj, zoo li quav ciab, thiab pob tshab ib nrab, ua rau nws yog ib yam khoom siv rwb thaiv tsev thiab txheej txheem zoo tshaj plaws rau cov xov hlau thiab cov cables. Nws cov txiaj ntsig tseem ceeb suav nrog:
(1) Cov khoom siv hluav taws xob zoo heev: kev tiv thaiv rwb thaiv tsev siab thiab lub zog dielectric; qis permittivity (ε) thiab dielectric poob tangent (tanδ) hla ntau zaus, nrog rau qhov tsawg kawg nkaus zaus vam khom, ua rau nws yuav luag yog qhov zoo tagnrho dielectric rau kev sib txuas lus cables.
(2) Cov khoom siv kho tshuab zoo: yoog tau tab sis tawv, nrog kev tiv thaiv kev hloov pauv zoo.
(3) Muaj zog tiv taus kev laus thermal, brittleness qis-kub, thiab tshuaj lom neeg ruaj khov.
(4) Kev tiv thaiv dej zoo heev nrog kev nqus dej tsawg; kev tiv thaiv rwb thaiv tsev feem ntau tsis txo qis thaum muab tso rau hauv dej.
(5) Ua ib yam khoom uas tsis yog polar, nws qhia tau tias muaj roj permeability siab, nrog LDPE muaj roj permeability siab tshaj plaws ntawm cov yas.
(6) Qhov hnyav tshwj xeeb qis, txhua yam qis dua 1. LDPE tshwj xeeb tshaj yog ntawm kwv yees li 0.92 g / cm³, thaum HDPE, txawm tias nws qhov ceev dua, tsuas yog nyob ib ncig ntawm 0.94 g / cm³.
(7) Cov khoom ua tau zoo: yooj yim yaj thiab ua kom yas yam tsis muaj kev lwj, txias yooj yim rau hauv cov duab, thiab tso cai rau kev tswj hwm qhov tseeb ntawm cov khoom geometry thiab qhov ntev.
(8) Cov xov hlau ua los ntawm polyethylene yog lub teeb yuag, yooj yim rau kev teeb tsa, thiab yooj yim rau kev xaus. Txawm li cas los xij, polyethylene kuj muaj ntau qhov tsis zoo: qhov kub thiab txias qis; kev kub hnyiab, tso tawm cov ntxhiab zoo li paraffin thaum hlawv; tsis zoo rau kev ntxhov siab ntawm ib puag ncig thiab kev tsis kam nkag. Yuav tsum tau saib xyuas tshwj xeeb thaum siv polyethylene ua rwb thaiv tsev lossis sheathing rau cov xov hlau hauv qab dej lossis cov xov hlau teeb tsa hauv cov dej ntws ntsug.
Cov Yas Polyethylene Rau Cov Hlau Thiab Cov Cables
(1) Cov Yas Polyethylene Uas Siv Tau Rau Kev Rwb Thaiv Kab Mob
Ua los ntawm cov polyethylene resin thiab cov antioxidants xwb.
(2) Yas Polyethylene Uas Tiv Thaiv Huab Cua
Feem ntau yog ua los ntawm polyethylene resin, antioxidants, thiab carbon black. Kev tiv taus huab cua nyob ntawm qhov loj me ntawm cov khoom me me, cov ntsiab lus, thiab kev sib kis ntawm cov carbon black.
(3) Yas Polyethylene Uas Tiv Thaiv Kev Nyuaj Siab Thiab Tawg Ib puag ncig
Siv cov polyethylene uas muaj cov ntsuas dej yaj qis dua 0.3 thiab qhov hnyav molecular faib me me. Cov polyethylene kuj tseem tuaj yeem sib txuas los ntawm kev siv tshuaj lossis tshuaj lom neeg.
(4) Cov Yas Polyethylene Uas Muaj Hluav Taws Xob Siab
Cov rwb thaiv tsev ntawm cov xov hluav taws xob siab xav tau cov yas polyethylene ntshiab heev, ntxiv nrog cov khoom ruaj khov hluav taws xob thiab cov extruders tshwj xeeb los tiv thaiv kev tsim cov khoob, tiv thaiv cov roj hmab tawm, thiab txhim kho kev tiv thaiv arc, kev tiv thaiv hluav taws xob, thiab kev tiv thaiv corona.
(5) Cov Yas Polyethylene Semiconductive
Tsim los ntawm kev ntxiv cov pa roj carbon dub uas ua rau muaj hluav taws xob rau hauv polyethylene, feem ntau yog siv cov pa roj carbon dub zoo, cov qauv siab.
(6) Thermoplastic Low-Pas Lom Zem Zero-Halogen (LSZH) Polyolefin Cable Compound
Cov tshuaj no siv cov polyethylene resin ua cov khoom siv hauv paus, suav nrog cov tshuaj tua hluav taws uas tsis muaj halogen, cov tshuaj tiv thaiv pa luam yeeb, cov tshuaj thermal stabilizers, cov tshuaj tua kab mob fungal, thiab cov xim, ua tiav los ntawm kev sib tov, plasticization, thiab pelletization.
Cov Polyethylene sib txuas (XLPE)
Nyob rau hauv qhov kev ua ntawm cov hluav taws xob muaj zog lossis cov neeg sawv cev sib txuas, cov qauv molecular linear ntawm polyethylene hloov mus rau hauv cov qauv peb-seem (network), hloov cov khoom siv thermoplastic mus rau hauv thermoset. Thaum siv ua rwb thaiv tsev,XLPEtuaj yeem tiv taus qhov kub thiab txias ua haujlwm tas mus li txog li 90 ° C thiab qhov kub luv luv ntawm 170–250 ° C. Cov txheej txheem sib txuas suav nrog kev sib txuas ntawm lub cev thiab tshuaj lom neeg. Kev sib txuas ntawm kev ua kom tsis muaj zog yog ib txoj kev siv lub cev, thaum cov tshuaj sib txuas ntawm cov tshuaj feem ntau yog DCP (dicumyl peroxide).
Lub sijhawm tshaj tawm: Plaub Hlis-10-2025