High molecular hnyav polyethylene: piav qhia, khoom, kev siv

2024 Tus sau: Howard Calhoun | [email protected]. Kawg hloov kho: 2023-12-17 10:28

Txhua hnub, cov ntaub ntawv tshiab tau los ntawm cov khoom siv dag zog tau nkag mus rau hauv qhov chaw ntawm tib neeg kev ua haujlwm. Ib qho ntawm cov no yog siab molecular hnyav polyethylene, uas tau dhau los ua cov khoom lag luam txij li xyoo 1950, tab sis tam sim no tsuas yog tau txais kev nyiam tiag tiag.

Kev piav qhia

High molecular hnyav polyethylene yog ib hom thermoplastic polymerized ethylene. Nws lub ntsiab feature yog ntev heev molecular chains. Lawv pom tau zoo dua thiab xa cov khoom thauj, "compensating" lawv nrog kev sib cuam tshuam hauv nruab nrab.

Cov khoom zoo li tsis txawv ntawm lwm hom yas. Nws yog odorless, tasteless, non-toxic. Nws tuaj yeem muab txhua yam xim los ntawm kev qhia txog xim. Tib lub sijhawm, nws muaj cov khoom sib txawv ntawm lwm cov polymers.

High molecular yuag polyethylene yog cov khoom siv tawv nrog lub zog zoo heev. Nws muaj peev xwm tiv tauskev nyuaj siab tseem ceeb. Nws tsis nqus dej noo, uas yog vim li cas nws tsis cuam tshuam nrog tib neeg cov tawv nqaij thiab hnov ntxhiab. Tsis tas li ntawd, nws muaj kev puas tsuaj siab (ntau dua li cov hlau) thiab qis coefficient ntawm kev sib txhuam.

Khoom muaj siab molecular hnyav polyethylene

Raws li twb tau sau tseg lawm, lub ntsiab feature ntawm no siab molecular hnyav polymer yog ntev molecular chains. Ntxiv mus, lawv yog taw qhia nyob rau hauv tib txoj kev. Lawv nyob yuav luag sib luag rau ib leeg. Qhov no piav qhia lub zog ntawm cov khoom siv.

Txawm hais tias muaj qhov hnyav molecular polyethylene ua cov saw ntev, kev sib txuas ntawm tus kheej molecules tsis muaj zog. Daim duab no yog ib qho kev txiav txim ntawm qhov loj dua qhov ntawm Kevlar, uas tsis muaj tsawg dua cov khoom siv. Cov yam ntxwv no ua rau cov polymer tsis kub resistant - nws melts ntawm qhov kub ntawm 144 degrees Celsius.

Cov polyethylene no tsis muaj esters, amines lossis hydroxyl pawg uas ua rau cov ntaub ntawv muaj kev cuam tshuam rau cov cheeb tsam hnyav thiab hnyav. Ua tsaug rau qhov no, cov khoom tsis raug rau dej, noo noo, aggressive reagents, microorganisms thiab UV rays.

Txoj kev rov ua dua tshiab

Cov kev cai raws li qhov siab molecular hnyav polyethylene yuav tsum tau tsim, GOST 16338-85 muaj. Raws li lawv, cov synthesis ntawm cov khoom yog nqa tawm los ntawm kev txiav txim ntawm metallocene catalysts ntawm lub monomer - ethylene. Rau kev tsim cov khoom ncaj qha, cov hauv qab no tseem ceeb ntawm kev ua yog siv:

1. Gel spinning. Cov khoom nyoostov nrog hnyav. Lub resulting loj yog yuam los ntawm lub qhov rau hauv dej. Cov filaments uas tshwm sim tau raug rho tawm haujlwm hauv qhov cub thaum rub tawm thiab tshem tawm cov kuab tshuaj.
2. Kub nias thiab sintering. Cov hmoov nplej yog compressed nrog lub zog loj, yog li tau txais cov khoom siv homogeneous. Tom qab ntawd nws raug rau kev kho cua sov - sintering ntawm qhov kub ntawm 150-200 degrees.
3. Plunger extrusion. Cov khoom siv raw yog yaj mus rau homogeneous, zoo li roj hmab loj, thiab tom qab ntawd nyem tawm los ntawm cov nozzles tshwj xeeb.

Gel spinning yog qhov dav tshaj plaws. Tom qab tag nrho, nws yog nyob rau hauv txoj kev no uas tau txais high-molecular polyethylene fibers nrog lub zog zoo.

siv tub rog

Fibers, rau kev tsim khoom uas siv cov khoom hnyav molecular polymer, tau siv dav los tsim cov khoom siv tiv thaiv tus kheej, tshwj xeeb tshaj yog cov tsho tiv thaiv mos txwv. Vim tias cov khoom zoo li no ntawm cov xov uas tsis tshua muaj lub ntiajteb txawj nqus thiab lub zog muaj zog (qhov piv ntawm cov ntsuas no yog 7-8 npaug siab dua li ntawm cov hlau), cov cuab yeej yog lub teeb thiab tiv taus cov mos txwv, shrapnel thiab lwm yam khoom puas.

Lub cev armor yog tsim los ntawm cov ntawv uas tau txais los ntawm kev siv cov fibers rau sab saum toj ntawm txhua lub kaum ntse ntse. Ua tsaug rau cov thev naus laus zis no, cov ntaub ntawv multiaxial tshwm sim - ib hom tshwj xeeb ntawm cov ntaub vitreous uas ua rau muaj kev ntxhov siab nyob rau txhua qhov kev taw qhia. High molecular hnyav polyethylene yog siv los tiv thaiv lub cev, caj dab. Cov khoommulti-axial fabrics pub armored tsheb tiv thaiv, nrog rau kev siv fibers los tsim cov hnab looj tes tiv thaiv.

daim ntawv thov kho mob

Hauv cov tshuaj, cov khoom hnyav molecular polyethylene yog siv los tsim kev cog qoob loo rau lub duav pob qij txha thiab cov leeg txha caj qaum, hauv caug pob qij txha. Nws yog thawj zaug siv rau lub hom phiaj no rov qab rau xyoo 1962. Thiab txij thaum ntawd los pib dominate.

Siv dav thiab hloov khoom siv - mesh lossis cross-linked polymer. Nws yog tau los ntawm shelling lub fibers ntawm siab molecular hnyav polyethylene nrog gamma quanta los yog electrons, uas sew lub threads ua ke. Tom qab ntawd, nws raug tshav kub, uas txo nws cov peev xwm redox.

Fibers raws li cov khoom siv raw no kuj siv rau suturing. Tus thawj coj hauv kev tsim cov khoom lag luam no yog DSM, uas muab kev lag luam kho mob nrog cov xov suture hu ua Dyneema Purity.

siv kev lag luam

High-molecular-yuag polyethylene ntawv, uas yog nkag mus rau kev lag luam hauv kev lag luam hauv pav ca billets 2 cm tuab, tau pom daim ntawv thov loj tshaj plaws hauv kev lag luam. Prestige-class yas qhov rais, PVC panels thiab PVC profiles ntawm ntau yam configurations yog tsim los ntawm nws lub hauv paus.

Nyob rau hauv mechanical engineering rau kev tsim cov nplhaib sib khi, cov kabmob, kev tsim cov khoom ua haujlwm hauv hydraulic lossis roj ib puag ncig, thiabkuj nyob rau hauv pneumatic installations nrog siab khiav hauj lwm siab, siab molecular hnyav polyethylene 1000 feem ntau yog siv - ib yam ntawm cov tseem ceeb ntawm polymer.