Key Difference – POM-H vs POM-C
POM stands rau polyoxymethylene, siab molecular hnyav thermoplastic polymer uas yog dav siv rau ntau daim ntawv thov kev lag luam. Nws tseem hu ua polyacetal, acetal, polyformaldehyde. POM copolymer ntawm formaldehyde yog tsim los ntawm -CH2O- rov ua units. POM polymers, feem ntau, muab cov khoom siv zoo heev xws li lub zog tensile siab, tsis muaj kev sib txhuam, siab qaug zog thiab, zoo zog thiab toughness. Tsis tas li ntawd, POM qhia tau hais tias muaj kev khawb siab ua haujlwm thiab tsis muaj dej noo. Tsis tas li ntawd, nws tiv taus ntau lub hauv paus muaj zog, ntau cov kuab tshuaj organic, thiab cov kua qaub tsis muaj zog, Txawm li cas los xij, vim yog cov qauv tshuaj ntawm POM, nws tsis ruaj khov hauv acidic tej yam kev mob (pH <4) thiab siab kub raws li cov polymer degraded nyob rau hauv cov no. tej yam kev mob. Li no, POM feem ntau yog copolymerized nrog cyclic ethers xws li ethylene oxide los yog dioxilane los cuam tshuam cov qauv tshuaj, yog li txhim khu kev ruaj ntseg ntawm cov polymer. POM muaj nyob rau hauv ob hom; POM-Cs thiab homopolymers (POM-Hs). Ob hom POM no txawv ntawm ntau txoj hauv kev, tab sis qhov sib txawv tseem ceeb ntawm POM-H thiab POM-C yog lawv qhov melting point. Lub melting point ntawm POM-C yog nruab nrab ntawm 160-175 ° C whereas, POM-H yog nyob nruab nrab ntawm 172-184 ° C. Lawv daim ntawv thov raug txiav txim raws li cov khoom ntawm POM-H thiab POM-C. Kab lus no piav qhia qhov txawv ntawm POM-H thiab POM-C.
YPolyoxymethylene
POM-H yog dab tsi?
POM-H sawv rau polyoxymethylene homopolymer. Thaum piv rau lwm qhov sib txawv ntawm POM, homopolymer muaj qhov sib txawv siab dua thiab yog 10-15% muaj zog dua li cov copolymer. Txawm li cas los xij, ob qho tib si variants muaj qhov cuam tshuam zoo ib yam. POM-H yog tsim los ntawm anionic polymerization ntawm formaldehyde, qhov twg crystallization tshwm sim zoo, ua rau muaj zog thiab zog. Feem ntau, POM-H muaj lub cev zoo thiab cov khoom siv kho tshuab zoo dua li POM-C. POM-H yog qhov zoo tshaj plaws rau cov ntawv thov uas cov khoom zoo li kev puas tsuaj zoo thiab tsis muaj coefficient ntawm kev sib txhuam yog xav tau.
POM-C yog dab tsi?
POM-C stands rau polyoxymethylene copolymer. Qhov no yog tsim los ntawm cationic polymerization ntawm trioxane. Thaum lub sijhawm txheej txheem no, ib qho me me ntawm comonomers tau ntxiv txhawm rau txhawm rau ua kom nruj, thaum txo qis crystallinity. Txawm li cas los xij, POM-C muaj qhov nruj thiab lub zog tsawg dua POM-H. Tab sis nws txoj kev ua tau zoo yog siab thaum piv rau POM-H. Vim li no, POM-C tau dhau los ua POM siv ntau tshaj plaws (75% ntawm tag nrho POM muag). POM-C yog qhov zoo rau cov ntawv thov uas cov cuab yeej zoo li tsis muaj coefficient ntawm kev sib txhuam yog xav tau.
POM-H thiab POM-C yog dab tsi?
Lub Npe
POM-H: Nws lub npe puv yog POM homopolymer.
POM-C: Nws lub npe puv yog POM copolymer.
YajYajProduced by
POM-C: Nws yog tsim los ntawm anionic polymerization ntawm formaldehyde.
POM-H: Nws yog tsim los ntawm cationic polymerization ntawm trioxane
Properties of POM-H and POM-C
Hardness and Stiffness
POM-H: POM-H nyuaj thiab tawv
POM-C: POM-C tsis nyuaj thiab tawv li POM-H.
Kev ua tiav
POM-H: Kev ua haujlwm tsawg.
POM-C: Kev ua haujlwm siab.
Melting Point
POM-H: Melting point yog 172-184 °C.
POM-C: Melting point yog 160-175 °C.
Kev ntsuas kub
POM-H: Ua haujlwm kub ntawm POM-H yog 194-244 ° C.
POM-C: Ua haujlwm kub ntawm POM-C yog 172-205 ° C.
Elastic modulus (MPa) (tensile nrog 0.2% dej ntsiab lus)
POM-H: Elastic modulus yog 4623.
POM-C: Elastic modulus yog 3105.
iav hloov kub (tg)
POM-H: iav hloov pauv kub yog -85 ° C.
POM-C: iav hloov pauv kub yog -60 ° C.
Tensile zog
POM-H: Tensile zog yog 70 MPa.
POM-C: Tensile zog yog 61 MPa.
Kev sib tw
POM-H: Elongation is 25%.
POM-C: Elongation yog 40-75%.
Usage
POM-H: POM-H sawv cev ib ncig ntawm 25% ntawm tag nrho POM muag.
POM-C: POM-C sawv cev ib ncig ntawm 75% ntawm tag nrho POM muag.
Applications
POM-H: Bearings, gears, conveyor belt links, seat bets thiab grinding accessory of hand mixtures are some example of POM-H.
POM-C: hluav taws xob kettles, dej jugs, tivthaiv nrog snap fits, tshuaj twj tso kua mis, chav dej teev, xov tooj keypads, vaj tse rau kev siv hauv tsev, thiab lwm yam. yog ib co kev siv ntawm POM-C.
