Qhov sib txawv ntawm LDPE, HDPE, thiab LLDPE
Polyethylene yog ib qho ntawm tsib qhov tseem ceeb hluavtaws cob, thiab Tuam Tshoj yog tam sim no tus neeg xa khoom thiab tus neeg siv khoom loj thib ob ntawm polyethylene. Polyethylene feem ntau muab faib ua high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE) peb pawg.
Kev sib piv ntawm cov khoom ntawm HDPE, LDPE thiab LLDPE cov ntaub ntawv
| HDPE | LDPE | LLDPE | |
|---|---|---|---|
| Cov ntxhiab tsw toxicity | Non-toxic, tasteless, tsw | Non-toxic, tasteless, tsw | Non-toxic, tasteless, tsw |
| ceev | 0.940-0.976g / cm3 | 0.910g0.940g 3 | 0.915g0.935g 3 |
| Crystalline | 85-65% | 45-65% | 55-65% |
| Molecular qauv | Tsuas muaj cov pa roj carbon-carbon thiab carbon-hydrogen bonds, uas yuav tsum tau muaj zog ntau dua kom tawg | Polymers muaj qhov hnyav dua molecular thiab xav tau lub zog tsawg dua kom tawg | Nws muaj cov qauv qis dua, cov saw caj dab, thiab cov saw luv luv, thiab yuav tsum muaj zog tsawg dua kom tawg. |
| softening point | 125-135 ℃ | 90-100 ℃ | 94-108 ℃ |
| Kev coj cwj pwm zoo | Siab zog, zoo toughness, muaj zog rigidity | Mechanical zog tsis zoo | Siab zog, zoo toughness, muaj zog rigidity |
| Tensile Zog | siab | Tsawg | ntau dua |
| Elongation thaum so | ntau dua | Tsawg | siab |
| Kev cuam tshuam rau lub zog | ntau dua | Tsawg | siab |
| Moisture-proof thiab waterproof kev ua tau zoo | Zoo permeability rau dej, dej vapor thiab cua, tsis tshua muaj dej nqus, thiab zoo anti-permeability | Tsis zoo noo noo thiab huab cua barrier zog | Zoo permeability rau dej, dej vapor thiab cua, tsis tshua muaj dej nqus, thiab zoo anti-permeability |
| Acid, alkali, corrosion, organic hnyav kuj | Resistant corrosion los ntawm muaj zog oxidants; resistant rau acid, alkali thiab ntau yam ntsev; insoluble nyob rau hauv tej organic solvents, thiab lwm yam. | Resistant rau acid, alkali thiab ntsev tov corrosion, tab sis tsis zoo hnyav kuj | Resistant rau acids, alkalis, thiab organic solvents |
| Kub / txias resistant | Nws muaj qhov ua tau zoo thaum tshav kub kub thiab txias tsis kam, txawm nyob rau hauv chav tsev kub thiab txawm nyob rau hauv qis kub ntawm -40F. Nws muaj kev cuam tshuam zoo heev thiab nws qhov kub thiab txias embrittlement kub yog | Tsawg kub tsis kam, tsis tshua muaj kub embrittlement kub | Zoo kub tsis kam thiab txias tsis kam, tsis tshua muaj kub embrittlement kub |
| Resistant rau ib puag ncig kev ntxhov siab tawg | zoo | zoo dua | zoo |
High-density Polyethylene
HDPE yog non-toxic, tasteless, odorless, thiab muaj ib tug ceev ntawm 0.940 ~ 0.976g / cm3, uas yog cov khoom ntawm polymerization nyob rau hauv tsis tshua muaj siab tej yam kev mob nyob rau hauv lub catalysis ntawm Ziegler catalyst, yog li high-density polyethylene kuj hu ua tsis tshua muaj siab. polyethylene.
Zoo:
HDPE yog non-polar thermoplastic resin nrog siab crystallinity tsim los ntawm ethylene copolymerization. Cov tsos ntawm thawj HDPE yog milky dawb, thiab nws yog translucent rau qee yam hauv seem meager. Nws muaj kev tiv thaiv zoo rau feem ntau cov tshuaj hauv tsev thiab kev lag luam, thiab nws tuaj yeem tiv thaiv corrosion thiab tawg ntawm cov oxidants muaj zog (concentrated nitric acid), acid thiab alkali ntsev thiab cov kuab tshuaj organic (carbon tetrachloride). Cov polymer tsis nqus dej noo thiab muaj dej tsis zoo rau chav, uas tuaj yeem siv rau kev tiv thaiv kev ya raws thiab seepage.
cons:
Qhov tsis zoo yog qhov kev laus ua haujlwm thiab kev ntxhov siab ib puag ncig tsis zoo li LDPE, tshwj xeeb tshaj yog cov thermal oxidation yuav txo nws cov kev ua tau zoo, yog li high-density polyethylene ntxiv antioxidants thiab ultraviolet absorbers los txhim kho nws qhov tsis txaus thaum ua cov yas yob.
Tsawg Tshaj Tawm Polyethylene
LDPE yog non-toxic, tasteless, tsw, thiab muaj ib tug ceev ntawm 0.910 ~ 0.940g / cm3. Nws yog polymerized nrog oxygen los yog organic peroxide raws li ib tug catalyst nyob rau hauv lub siab ntawm 100 ~ 300MPa, kuj hu ua high-pressure polyethylene.
Zoo:
Tsawg ntom polyethylene yog lub teeb tshaj plaws ntawm polyethylene cob. Piv nrog rau high-density polyethylene, nws crystallinity (55% -65%) thiab softening point (90-100 ℃) yog qis dua. Nws muaj zoo softness, extensibility, pob tshab, txias kuj thiab processability. Nws cov tshuaj ruaj khov yog qhov zoo, tuaj yeem tiv taus acid, alkali thiab ntsev aqueous tov; Zoo hluav taws xob rwb thaiv tsev thiab roj permeability; Kev nqus dej tsawg; Yooj yim rau hlawv. Cov cuab yeej yog mos, nrog zoo extensibility, hluav taws xob rwb thaiv tsev, tshuaj stability, kev ua tau zoo thiab kub tsis kam (ua hauj rau -70 ℃).
cons:
Qhov tsis zoo yog tias nws lub zog txhua yam, kev rwb thaiv tsev ya raws, roj rwb thaiv tsev thiab cov kuab tshuaj tiv thaiv tsis zoo. Cov qauv molecular tsis tu ncua txaus, crystallinity (55% -65%) yog qhov tsawg, thiab crystallization melting point (108-126 ℃) kuj qis. Nws lub zog muaj zog yog qis dua li ntawm high-density polyethylene, nws cov coefficient anti-seepage, tshav kub tsis kam thiab tiv thaiv kev laus tsis zoo, thiab nws yooj yim rau decompose thiab discolor nyob rau hauv tshav ntuj lossis kub kub, ua rau poob qis hauv kev ua haujlwm, yog li polyethylene low-density ntxiv cov tshuaj antioxidants thiab ultraviolet absorbers los txhim kho nws qhov tsis zoo thaum ua cov ntawv yas.
Linear Low Density Polyethylene
LLDPE yog non-toxic, tasteless, tsw, thiab muaj qhov ceev ntawm 0.915 thiab 0.935g / cm3. Nws yog ib tug copolymer ntawm ethylene thiab ib tug me me ntawm advanced alpha-olefin (xws li butene-1, hexene-1, octene-1, tetrmethylpentene-1, thiab lwm yam) polymerized nyob rau hauv lub siab los yog tsis tshua muaj siab nyob rau hauv qhov kev txiav txim ntawm ib tug catalyst. . Cov qauv molecular ntawm cov pa LLDPE yog tus cwj pwm los ntawm nws cov kab mob qaum, nrog ob peb los yog tsis muaj cov saw ntev ntev, tab sis muaj qee cov saw luv luv. Qhov tsis muaj cov saw ntev ntev ua rau cov polymer ntau crystalline.
Piv nrog LDPE, LLDPE muaj qhov zoo ntawm lub zog siab, zoo toughness, muaj zog rigidity, tshav kub tsis kam, txias tsis kam, thiab lwm yam, tab sis kuj muaj zoo tiv thaiv rau ib puag ncig kev nyuaj siab tawg, tsim kua muag zog thiab lwm yam khoom, thiab muaj peev xwm tiv taus acid, alkali, organic solvents thiab lwm yam.
Kev paub qhov txawv
LDPE: Sensory identification: muag muag; Dawb pob tshab, tab sis lub pob tshab yog qhov nruab nrab. combustion identification: hlawv nplaim daj thiab xiav; Thaum hlawv tsis muaj pa taws, muaj cov ntxhiab tsw paraffin, yaj dripping, yooj yim los kos hlau.
LLDPE: LLDPE tuaj yeem swell nyob rau hauv kev sib cuag nrog benzene rau lub sij hawm ntev, thiab ua nkig nyob rau hauv kev sib cuag nrog HCL rau lub sij hawm ntev.
HDPE: Kev ua haujlwm kub ntawm LDPE yog qis dua, txog 160 degrees, thiab qhov ceev yog 0.918 txog 0.932 grams / cubic centimeter. HDPE ua haujlwm kub siab dua, txog 180 degrees, qhov ceev kuj tseem siab dua.
Ntsiab lus
Nyob rau hauv cov ntsiab lus, saum toj no peb yam khoom ua si lawv lub luag hauj lwm tseem ceeb nyob rau hauv ntau hom seepage tiv thaiv engineering. HDPE, LDPE thiab LLDPE peb hom ntaub ntawv muaj cov rwb thaiv tsev zoo thiab noo noo-pov thawj, impermeability, non-toxic, tasteless, odorless kev ua tau zoo ua rau nws nyob rau hauv kev ua liaj ua teb, aquaculture, dag lub pas dej, reservoirs, dej daim ntaub ntawv kuj yog heev nthuav, thiab los ntawm Ministry. Kev ua liaj ua teb ntawm Tuam Tshoj Fisheries Bureau, Shanghai Academy ntawm Fisheries Science, lub koom haum ntawm fishery machinery thiab cov cuab yeej los txhawb thiab nrov daim ntawv thov.
Nyob rau hauv nruab nrab ib puag ncig ntawm cov kua qaub muaj zog, muaj zog alkalis, muaj zog oxidants thiab cov kuab tshuaj organic, cov khoom siv ntawm HDPE thiab LLDPE tuaj yeem ua tau zoo thiab siv tau, tshwj xeeb tshaj yog HDPE ntau dua li lwm yam ob cov ntaub ntawv hais txog kev tiv thaiv kom muaj zog acids, muaj zog. alkalis, muaj zog oxidation zog thiab tsis kam mus rau cov kuab tshuaj organic. Yog li ntawd, HDPE anti-corrosion kauj tau siv tag nrho hauv kev lag luam tshuaj thiab kev tiv thaiv ib puag ncig.
LDPE kuj muaj cov kua qaub zoo, alkali, ntsev tov cov yam ntxwv, thiab muaj qhov zoo extensibility, hluav taws xob rwb thaiv tsev, tshuaj stability, kev ua tau zoo thiab kub tsis kam, yog li nws yog dav siv nyob rau hauv kev ua liaj ua teb, dej cia aquaculture, ntim, tshwj xeeb tshaj yog tsis tshua muaj kub ntim thiab cov ntaub ntawv cable.
