Kev tsim cov txheej txheem ntawm polyethylene thiab polypropylene raw cov ntaub ntawv yog qhov zoo sib xws, thiab cov khoom siv tuaj yeem siv los ua cov yeeb yaj kiab yas, cov khoom siv tshuaj molded, cov kav dej yas, thiab lwm yam. Muaj ntau ntau, peb pom tias ob cov khoom siv raw muaj qhov zoo sib xws hauv cov khoom thiab siv. Tab sis qhov tseeb, tseem muaj ntau qhov sib txawv hauv kev siv cov khoom siv polypropylene thiab polyethylene raw khoom. Tus editor yuav muab rau koj ib qho kev ntsuam xyuas ntawm cov yam ntxwv ntawm kev ua tau zoo ntawm polypropylene thiab polyethylene, thiab sib tham txog qhov sib txawv ntawm cov khoom siv tom qab ob qhov sib xyaw ua ke sib txawv. Nyob rau hauv cov nqe lus ntawm cov khoom siv rau tuj lub hnab, polypropylene tuaj yeem siv los ua ib lub hnab sab nrauv, thaum polyethylene tsuas yog siv los ua ib lub hnab zaj duab xis sab hauv.
1. Los ntawm kev xaav ntawm cov cua kub tsis kam, qhov kub tsis kam ntawm polypropylene yog siab dua li ntawm polyethylene. Nyob rau hauv ib txwm muaj xwm txheej, lub melting kub ntawm polypropylene yog hais txog 40% -50% siab tshaj polyethylene, uas yog hais txog 160-170 ℃, yog li Cov khoom yuav raug sterilized ntawm qhov kub siab tshaj 100 ° C, thiab yuav tsis deformed ntawm 150 ° C nyob rau hauv cov xwm txheej tsis muaj zog sab nraud. Hauv lub neej niaj hnub, peb yuav pom tias"5" polypropylene su boxes feem ntau yog siv los ua kom sov cov zaub mov hauv microwave ncu (qhov dav dav ntawm qhov cub microwave cua sov yog 100-140 ℃), thiab polyethylene tsis tuaj yeem siv los ua yas rau microwave ncu vim nws tsis zoo cua sov. , suav nrog cov thawv noj su thiab hnab yas. Ib yam li ntawd, nyob rau hauv lub tshav pob ntawm cov yeeb yaj kiab zoo tib yam, cov hnab ntim polyethylene yog qhov tsim nyog rau kev siv ntawm qhov kub qis dua 90 ° C, thaum lub hnab ntim polypropylene tuaj yeem siv rau qhov kub thiab txias.
2. Los ntawm cov foundations ntawm rigidity thiab tensile lub zog, lub ntsiab yam ntxwv ntawm polypropylene yog nws tsis tshua muaj ceev, zoo dua txhua yam khoom dua polyethylene, thiab koj rigidity. Piv txwv li, polypropylene tau maj mam nthuav mus rau kev sib tw nrog engineering plastics (PA / PC). Kev sib tw yog siv dav hauv kev lag luam hluav taws xob, khoom siv hluav taws xob thiab tsheb. Nyob rau tib lub sijhawm, vim tias polypropylene muaj lub zog tensile siab thiab khoov zoo, nws yog hu ua" 100-fold yas". Nws yog khoov 1 lab lub sij hawm thiab tsis ua dawb thaum khoov. Qhov no kuj tseem muab cov lus qhia rau peb kom paub qhov txawv ntawm cov khoom siv polypropylene. Cov cim zais rau kev rov ua dua tshiab thiab txheeb xyuas cov khoom.
3. Los ntawm qhov kev xav ntawm qhov kub thiab txias tsis kam, polypropylene muaj qhov tsis muaj zog ntawm qhov kub thiab txias dua li polyethylene. Qhov cuam tshuam lub zog ntawm 0 ° C tsuas yog ib nrab ntawm qhov ntawm 20 ° C, thaum lub brittleness kub ntawm polyethylene feem ntau ncav cuag qis dua -50 ° C; Qhov nce hauv huab hwm coj tuaj yeem qis li -140 ° C. Yog li ntawd, yog tias cov khoom yuav tsum tau siv nyob rau hauv qhov kub thiab txias ib puag ncig, nws tseem yuav tsum tau xaiv polyethylene ua raw khoom. Feem ntau, cov tais uas siv rau cov khoom noj hauv tub yees yog ua los ntawm cov khoom siv polyethylene.
4. Los ntawm kev xav ntawm kev laus tiv thaiv, kev laus tiv thaiv ntawm polypropylene tsis muaj zog dua li ntawm polyethylene. Cov qauv ntawm polypropylene zoo ib yam li polyethylene. Nyob rau hauv qhov kev txiav txim ntawm oxidative degradation. Cov khoom siv polypropylene ntau tshaj plaws uas ua rau muaj kev laus hauv lub neej niaj hnub yog lub hnab woven. Lub hnab ntim tau yooj yim tawg thaum raug tshav ntuj ntev. Qhov tseeb, txawm hais tias kev laus tiv thaiv ntawm polyethylene yog siab dua li ntawm polypropylene, piv nrog rau lwm cov ntaub ntawv raw, nws qhov kev ua tau zoo tsis zoo heev, vim tias cov polyethylene molecule muaj me me ntawm ob daim ntawv cog lus thiab ether bonds, thiab nws cov huab cua tsis kam. zoo. , Hnub thiab nag kuj tuaj yeem ua rau kev laus.
5. Los ntawm qhov kev xav ntawm kev hloov pauv, txawm hais tias polypropylene muaj lub zog siab, nws muaj kev hloov pauv tsis zoo, thiab kev hais lus, nws muaj kev cuam tshuam tsis zoo. Yog li ntawd, thaum nws siv los ua cov khoom ua yeeb yaj kiab, nws daim ntawv thov teb tseem txawv ntawm polyethylene. Polypropylene zaj duab xis yog siv ntau dua rau kev ntim khoom ntim. Hais txog cov kav dej, cov polypropylene yooj yim tsis tshua siv rau kev tsim khoom, thiab kev sib txuas ntawm polypropylene, uas yog ib hom PPR yeeb nkab, xav tau. Vim tias cov polypropylene zoo tib yam muaj kev cuam tshuam tsis zoo thiab yooj yim rau kev tawg, nws yog ib qho tsim nyog yuav tsum tau ntxiv cov kev hloov pauv hauv cov ntawv thov, thiab cov khoom siv ntxiv yuav tsum tau siv los txhim kho kev cuam tshuam hauv kev siv xws li bumpers.
PE thiab PE sib xyaw ua haujlwm
Cov nyhuv ntawm PE hom ntawm qhov cuam tshuam kev ua haujlwm ntawm kev sib xyaw ua ke
Ntau hom PE tuaj yeem txhim kho chav tsev kub qhov cuam tshuam lub zog ntawm PP, tab sis qhov sib txawv yog pom tseeb heev.
Rau PP / HDPE blends, thaum qhov loj ntawm HDPE tsawg dua 60%, lub zog ntawm cov khoom sib xyaw yog qhov tsis hloov pauv; Thaum qhov loj feem ntawm HDPE siab dua 60%, qhov cuam tshuam lub zog ntawm kev sib xyaw ua ke nce.
Rau PP / LDPE blends, tsuas yog thaum qhov loj ntawm LDPE siab dua 60%, qhov cuam tshuam lub zog tuaj yeem txhim kho tau zoo.
Rau PP / LLDPE blends, thaum qhov loj ntawm LDPE ntau dua 40%, qhov cuam tshuam lub zog tau zoo dua. Thaum qhov loj ntawm LLDPE nce mus txog 70%, qhov cuam tshuam lub zog ntawm qhov sib tov yog 37.5kJ / m2, uas tuaj yeem ncav cuag 20 npaug ntawm qhov cuam tshuam lub zog ntawm PP, uas yog 10 npaug thiab 4 npaug ntawm PP / HDPE thiab PP / LDPE. blends nrog tib tus nqi. .
Thaum qhov kub thiab txias (-18 ° C), qhov sib txawv ntawm kev txhim kho ntawm PP toughness los ntawm peb hom PE yog tib yam li nyob rau hauv chav tsev kub, thiab LLDPE muaj qhov zoo tshaj plaws toughening nyhuv ntawm PP. Thaum qhov sib piv loj ntawm PP / LLDPE yog 30/70, qhov cuam tshuam lub zog ntawm kev sib xyaw yog 23.2kJ / m2, uas yog 20 npaug ntawm PP ntshiab. Nyob rau tib lub sijhawm, qhov cuam tshuam lub zog ntawm PP / HDPE thiab PP / LDPE blends tsuas yog txog 5kJ / m2. Qhov no qhia ntxiv tias thaum tib lub zog cuam tshuam tau tiav, LLDPE yog qhov tsawg tshaj plaws, uas txhais tau hais tias qhov rigidity ntawm PP tuaj yeem tswj tau ntau dua; thiab ntawm tib tus nqi, qhov cuam tshuam lub zog ntawm LLDPE-hloov PP yog qhov zoo tshaj plaws, uas ua rau cov khoom tau zoo dua toughness.
Cov nyhuv ntawm kev sib tov rau cov nyhuv toughening
Qhov cuam tshuam lub zog ntawm cov qauv sib xyaw nrog ntxaib-ntsia hlau extruder yog qhov siab tshaj plaws, thiab qhov cuam tshuam kev ua haujlwm ntawm cov qauv tau txais los ntawm txoj kev txhaj tshuaj ncaj qha yog qhov phem tshaj. Txij li qhov ntev ntawm cov ntsia hlau ntawm lub tshuab txhaj tshuaj yog me dua li ntawm extruder, cov nyhuv shearing thiab mixing yog me me, thiab cov nyhuv yog qhov tseeb heev. Raws li kev sib xyaw sib txawv, qhov cuam tshuam kev ua haujlwm ntawm cov khoom pov thawj tib txoj cai, uas yog, feem ntau ntawm LLDPE pib los ntawm 40%, thiab raws li tus nqi ntawm LLDPE nce, nws qhov cuam tshuam lub zog nce ntau heev; nws qhia tau hais tias txoj kev sib tov muaj kev cuam tshuam loj heev rau kev cuam tshuam kev ua haujlwm ntawm kev sib xyaw ua ke. Influence, tab sis txoj cai tseem zoo li qub.
Cov qauv sab hauv ntawm PP / LLDPE sib xyaw
Thaum qhov loj ntawm LLDPE tsawg dua 50%, qhov cuam tshuam hla ntu ntawm qhov sib xyaw ua ke yog du thiab tiaj tus, qhia txog cov yam ntxwv ntawm pob txha tawg; Thaum qhov loj ntawm LLDPE ntau tshaj 50%, cov khoom hla ntu nthuav tawm cov yam ntxwv ntawm cov pob txha tawg, filaments tshwm, thiab ntu ntu tsis sib xws. Muaj cov cim kua muag thiab ob-theem interface zoo li yuav plooj. Lub sijhawm no, lub zog tawm los ntawm cov khoom siv tau nce sai; Thaum tus nqi ntawm LLDPE nce mus rau 70%, nws tuaj yeem pom meej tias PP tau cuam tshuam rau hauv lub network. Yog li ntawd, cov khoom muaj ib tug macroscopic saib. Lub zog muaj zog heev.
Qhov loj ntawm cov ntshiab PP spherulites yog qhov loj heev, thiab qhov sib cuam tshuam ntawm cov spherulites yog qhov tseeb, yog li qhov cuam tshuam kev ua haujlwm ntawm PP yog qhov tsis zoo. Hauv qhov sib piv, cov nplais ntawm LLDPE yog qhov me me, thiab qhov sib cuam tshuam ntawm cov muaju kuj tseem fuzzy, yog li nws cov kev cuam tshuam zoo heev.
Qhov sib txawv ntawm crystalline morphology ntawm PP thiab LLDPE yog tshwm sim los ntawm qhov sib txawv ntawm crystallization tus nqi ntawm ob: PP muaj ib tug qeeb crystallization tus nqi (3.3X102nm / s), loj siv lead ua kev loj hlob, thiab tsawg dua kev sib txuas ntawm cov muaju, yog li siv lead ua interface. yog tseeb; thaum LLDPE Lub crystallization tus nqi yog ceev heev (8.3X102nm / S), cov muaju yog me me thiab muaj ntau qhov kev sib txuas ntawm cov muaju, yog li qhov cuam tshuam ntawm cov muaju yog qhov muag plooj.
Thaum LLDPE ntxiv rau PP, nws tuaj yeem pom tias qhov loj ntawm PP spherulites yog qhov txo qis, thiab qhov sib cuam tshuam ntawm cov crystals ua qhov muag plooj, uas yog qhov zoo los txhim kho qhov cuam tshuam ntawm cov khoom siv. Thaum tus nqi ntawm LLDPE nce, PP spherulites raug txo ntxiv. Thaum cov feem loj ntawm LLDPE nce mus txog 70%, PP crystals tau muab faib ua smashed crystals, thiab qhov cuam tshuam ntawm cov crystals ploj tag. Nws yog sib xyaw nrog LLDPE thiab nyuaj rau kev paub qhov txawv. Yog li ntawd, qhov sib xyaw ua ke Lub zog cuam tshuam yog siab heev thiab nws tsis yooj yim rau tawg. Qhov no qhia tau hais tias qhov sib ntxiv ntawm LLDPE refines lub spherulites ntawm PP thiab ua rau kom muaj kev sib txuas ntawm cov muaju, uas yog lwm qhov laj thawj tseem ceeb rau kev txhim kho cov tawv tawv ntawm cov khoom sib xyaw.
Kev cuam tshuam ntawm LLDPE ntau npaum li cas ntawm kev sib xyaw ua haujlwm
Raws li tus nqi ntawm LLDPE nce, cov txiaj ntsig kev ntxhov siab ntawm kev sib xyaw ua ke txo qis, thaum lub elongation ntawm kev tawg maj mam nce, qhia txog kev sib raug zoo linear. Raws li tus nqi ntawm LLDPE nce, Vicat softening point ntawm cov khoom sib xyaw txo. Thaum qhov loj ntawm LLDPE yog 40% -60%, Vicat softening point ntawm cov khoom sib xyaw tseem nyob ze rau 120 degrees. Raws li tus nqi ntawm LLDPE nce, qhov cuam tshuam lub zog ntawm cov khoom nce, thaum lub zog tensile tawm los, tensile modulus, thiab Vicat softening point txo.
Hauv LLDPE-based system, thaum cov khoom raug cuam tshuam, ntxiv rau LLDPE theem siv ntau lub zog thiab txhim kho lub zog ntawm cov khoom, nws kuj txo qhov loj ntawm PP siv lead ua vim qhov ntxig, segmentation thiab ua kom zoo dua. PP spherulites los ntawm LLDPE. Tus naj npawb ntawm kev sib txuas ntawm cov crystals nce, yog li ua rau muaj kev cuam tshuam lub zog ntawm cov khoom siv. Nyob rau hauv PP / LLDPE blend system, thaum qhov loj ntawm LL-DPE yog 40% -70%, qhov sib xyaw maj mam tsim cov qauv sib txuas sib txuas, uas muaj cov yam ntxwv ntawm rigidity thiab toughness.