Khoom noj khoom haus- Qib Plastic Raw Materials: Virgin, Recycled, thiab Reclaimed Materials

Kev txheeb xyuas cov zaub mov- Qib Plastic Raw Materials: 3 Cov Txheej Txheem Sib Txawv Sib Txawv rau Cov Khoom Siv Virgin, Cov Khoom Siv Rov Qab, thiab Cov Khoom Siv Rov Qab. Nyob rau hauv kev tswj zoo ntawmzaub mov- qibPP yas raw cov ntaub ntawv, kom meej qhov txawv ntawm nkauj xwb, recycled, thiab reclaimed cov ntaub ntawv yog ib tug tseem ceeb kauj ruam nyob rau hauv kev ua kom cov khoom muaj kev ruaj ntseg thiab zoo stability. Txawm hais tias peb hom khoom no zoo sib xws, lawv muaj qhov sib txawv tseem ceeb hauv cov qauv molecular, tshuaj muaj pes tsawg leeg, thiab lub cev muaj zog. Raws li cov qauv tshiab hauv tebchaws thiab cov kev coj ua hauv kev lag luam, cov hauv qab no yuav nthuav dav peb txoj hauv kev txheeb xyuas qhov tseem ceeb thiab lawv cov txheej txheem ua haujlwm.

1.1 Kev txhais thiab qhov sib txawv ntawm Virgin, Recycled, thiab Reclaimed Materials

Cov khoom siv nkauj xwb hais txog PP cov ntaub ntawv ncaj qha polymerized los ntawm petrochemical raw cov ntaub ntawv, tus cwj pwm los ntawm cov qauv molecular tsis tu ncua thiab siab purity. Cov khoom siv no yeej tsis tau siv, muaj cov saw hlau ua tiav, ib qho tshuaj lom neeg muaj pes tsawg leeg, thiab tag nrho cov ntsuas kev ua tau zoozaub mov- qibqauv. Virgin PP muaj cov qauv isotactic heev, nrog rau tag nrho cov methyl sab pawg nyob rau tib sab ntawm lub ntsiab saw, tsim ib tug helical zoo, nrog ib tug crystallinity ntawm 50% -80% thiab ib tug melting point ntawm 160-176 degree.

Cov khoom siv rov ua dua yog hais txog PP cov khib nyiab uas tsuas yog crushed thiab ntxuav tom qab siv, feem ntau yog los ntawm cov khoom seem, cov khoom tsis zoo, lossis tom qab- cov khoom siv yas los ntawm cov txheej txheem tsim khoom. Txawm hais tias hom khoom no khaws cov qauv ntawm PP, nws yuav muaj cov khoom seem ntxiv, cov xim, impurities, thiab degradation cov khoom tsim tawm thaum siv. Cov saw hlau molecular ntawm cov khoom siv rov ua dua tshiab tuaj yeem tawg qee qhov, thiab qhov hnyav molecular faib dav dua, ua rau muaj kev hloov pauv ntawm kev ua haujlwm.

1.2 Performance Parameter Comparative Analysis

Hais txog lub cev muaj zog, muaj qhov sib txawv tseem ceeb ntawm peb hom khoom. Qhov ntom yog qhov ntsuas qhov sib txawv tshaj plaws. Qhov ceev ntawm nkauj xwb PP feem ntau yog nyob rau hauv thaj tsam ntawm 0.90-0.915 g / cm³, thaum qhov ceev ntawm PP rov qab yog feem ntau nyob rau hauv thaj tsam ntawm 0.9-0.91 g / cm³. Qhov sib txawv ntawm ob yog me me tab sis tseem tuaj yeem paub qhov txawv siv cov cuab yeej precision. Tensile zog yog lwm qhov tseem ceeb parameter. Lub zog tensile ntawm nkauj xwb PP tuaj yeem ncav cuag 30-40 MPa, thaum lub zog tensile ntawm cov khoom siv dua tshiab tsuas yog 20-30 MPa, 20-30% qis dua li ntawm cov khoom nkauj xwb.

Nyob rau hauv cov nqe lus ntawm thermal zog, nkauj xwb PP nthuav qhia ib leeg, huv si, thiab du melting ncov nyob rau hauv nws melting nkhaus, nrog ib tug ncov kub ntawm 165-169 degree. Lub melting nkhaus ntawm cov khoom siv rov ua dua feem ntau qhia ntau lub siab melting, nyob ib ncig ntawm 132℃thiab 165 degree, vim yog cov ntsiab lus sib txawv ntawm PP los ntawm ntau qhov chaw. Tsis tas li ntawd, vim muaj ntau cov kauj ruam ua, cov yaj ntws tus nqi (MFR) ntawm cov khoom siv rov ua dua tau nce ntxiv, uas yog qhov tshwm sim ntawm cov saw hlau molecular tawg ua rau txo qis hauv molecular hnyav.

Qhov sib txawv ntawm cov tshuaj muaj pes tsawg leeg yog complex. Cov tshuaj muaj pes tsawg leeg ntawm nkauj xwb PP yog qhov yooj yim, feem ntau muaj PP polymer thiab ib qho me me ntawm cov khoom ntxiv xws li antioxidants. Cov khoom siv rov ua dua tshiab thiab rov ua dua tshiab tuaj yeem muaj ntau yam kuab paug, nrog rau cov hlau hnyav (cov ntsiab lus uas yuav muaj ntau tshaj li ob qhov kev txiav txim siab siab dua li cov khoom siv nkauj xwb), cov tshuaj tua kab residues, toughening agents, adhesives, bacteria, viruses, and other harms. Lub xub ntiag ntawm cov pa phem no tsis tsuas yog cuam tshuam rau kev ua haujlwm ntawm cov khoom siv tab sis, qhov tseem ceeb tshaj, yuav ua rau muaj kev hem thawj rau kev nyab xeeb khoom noj.

2.1 Txoj Kev Ntsuas Kev Ntsuas Lub Cev

Physical performance testing is the most basic and commonly used identification method, mainly including density measurement, melt flow index testing, and thermal analysis.
Kev ntsuas qhov ceev yog thawj kauj ruam hauv kev txheeb xyuas cov ntaub ntawv PP. Raws li lub teb chaws tus qauv GB/T 1033.1-2008 thiab ISO 1183-1:2019, qhov yuav tsum tau ceev rau zaub mov- qib PP yog 0.90-0.91 g/cm³. Cov txheej txheem tshwj xeeb suav nrog txoj kev immersion, txoj kev ua kua pycnometer, thiab cov txheej txheem gradient kem density. Ntawm cov txheej txheem no, txoj kev ceev gradient kem txoj kev yog qhov tseeb tshaj plaws. Nws suav nrog muab cov qauv tso rau hauv ib qho kev npaj meej n-heptane-ethanol gradient tov thiab txiav txim siab tus nqi ntom raws li nws txoj haujlwm raug ncua. Kev ntsuas yuav tsum tau ua nyob rau hauv qhov kub thiab txias ib puag ncig ntawm 23 ± 0.5℃kom tshem tawm cov thermal expansion yuam kev. Niaj hnub nimno cov chaw soj nstuam dav siv tsis siv neeg densimeters, uas muab Archimedes 'txoj cai nrog kev vibration zaus ntsuas tshuab, txhim kho qhov ntsuas qhov tseeb rau ± 0.0001 g / cm³.

Hauv kev xyaum, qhov ntom ntawm nkauj xwb PP feem ntau ruaj khov nyob rau hauv thaj tsam ntawm 0.905-0.910 g / cm³, thaum cov khoom siv rov ua dua tuaj yeem pom qhov sib txawv loj dua vim tias muaj peev xwm suav nrog lwm cov yas lossis impurities. Qhov sib txawv ntawm qhov ntom ntom ntawm cov khoom siv rov ua dua yog qhov nyuaj dua, nyob ntawm lawv qhov chaw thiab kev siv thev naus laus zis. Nws yuav tsum raug sau tseg tias kev ntsuas qhov ceev ib leeg tsis tuaj yeem paub qhov txawv ntawm peb hom khoom; lwm txoj hauv kev yuav tsum tau ua ke rau kev txiav txim siab.

Qhov ntsuas qhov ntsuas kub (MFR) yog qhov ntsuas tseem ceeb rau kev ntsuam xyuas cov khoom ua haujlwm fluidity. Raws li tus qauv GB / T 3682, lub melt flow indexer yog siv los ntsuas tus nqi ntawm cov khoom extruded los ntawm tus qauv tuag hauv 10 feeb ntawm qhov kub thiab txias (feem ntau 230 degree) thiab load (2.16 kg), nrog rau chav tsev yog g / 10min. Lub melt flow rate ntawm zaub mov-qib PP feem ntau yog tswj nyob rau hauv thaj tsam ntawm 2-10 g/10min, thaum lub hom phiaj PP yog 0.5-30 g/10min.

Qhov kev ntsuam xyuas cov dej ntws tau zoo tshwj xeeb hauv kev paub qhov txawv ntawm cov nkauj xwb thiab cov khoom siv rov ua dua tshiab. Cov kev tshawb fawb tau pom tias tom qab ntau lub voj voog ua haujlwm, PP tau txais kev sib tsoo ntawm cov saw hlau vim yog lub zog shear, ua rau txo qis hauv molecular hnyav thiab nce MFR tus nqi tseem ceeb. Tus nqi MFR ntawm nkauj xwb PP yog qhov ruaj khov, thaum MFR tus nqi ntawm cov khoom siv rov qab tuaj yeem yog ob peb zaug siab dua li ntawm cov khoom nkauj xwb. Piv txwv li, ib pawg ntawm nkauj xwb PP yuav muaj MFR ntawm 5 g / 10min, thaum cov khoom siv rov ua dua 5 zaug yuav muaj MFR ntawm 15-20 g / 10min. Nws yuav tsum raug sau tseg tias qhov kev hloov pauv ntawm PE-LD yog qhov txawv; nws MFR txo qis nrog kev ua haujlwm ntau ntxiv, vim tias PE-LD feem ntau cuam tshuam cov kev sib txuas sib txuas ntau dua li cov kev cuam tshuam ntawm cov saw hlau. Kev ntsuas cua sov, suav nrog kev ntsuas qhov ntsuas qhov sib txawv (DSC) thiab ntsuas ntsuas ntsuas ntsuas ntsuas (TGA), yog ib txoj hauv kev zoo tshaj plaws rau kev txheeb xyuas cov ntaub ntawv PP. DSC raug txiav txim siab qhov melting point, crystallization kub, crystallinity, thiab oxidation induction lub sij hawm (OIT) ntawm cov khoom los ntawm kev ntsuas qhov kub txaus qhov sib txawv ntawm cov qauv thiab cov ntaub ntawv siv. TGA soj ntsuam cov thermal stability thiab decomposition tus cwj pwm ntawm ib yam khoom los ntawm kev ntsuas qhov kev hloov ntawm cov qauv loj nrog kub los yog lub sij hawm.

Hauv kev sim DSC, nkauj xwb PP feem ntau pom ib qho, ntse melting ncov nrog lub ncov kub ntawm 165-169℃thiab siab crystallinity. Rov ua dua PP, vim yog cov saw hlau molecular scission thiab qhov dav ntawm qhov hnyav ntawm molecular faib, qhia tau hais tias qhov dav dua melting ncov nyob rau hauv nws DSC nkhaus, thiab tej zaum yuav muaj ntau yam melting peaks. Piv txwv li, PP rov ua dua tshiab tuaj yeem pom lub ncov me me nyob ib puag ncig 132℃(tejzaum nws yog vim tsis muaj cov khoom hnyav molecular lossis lwm yam yas) thiab qhov siab siab ntawm 165 degree. Tsis tas li ntawd, qhov crystallinity ntawm PP rov qab yog feem ntau qis dua li ntawm nkauj xwb PP, vim yog cov qauv saw molecular puas tsuaj los ntawm ntau lub voj voog ua haujlwm.

TGA tsom xam tuaj yeem qhia qhov sib txawv ntawm qhov thermal stability ntawm cov ntaub ntawv. Virgin PP feem ntau muaj cov thermal decomposition kub tshaj 300 degree, thiab cov txheej txheem decomposition yog yooj yim. Rov ua dua PP, vim muaj ntau yam additives thiab impurities, nthuav tawm ntau cov thermal decomposition tus cwj pwm, muaj peev xwm pib decompose ntawm qis kub thiab qhia ntau theem poob thaum lub sij hawm decomposition. Nws yog ib qho tseem ceeb tshwj xeeb tshaj yog tias cov seem ntawm cov khoom siv rov ua dua PP sib txawv heev, xws li 0.2% mus rau 66%, thaum cov seem ntawm nkauj xwb PP feem ntau yog nyob nruab nrab ntawm 0.2% thiab 0.5%.

2.2 Cov txheej txheem tshuaj ntsuam xyuas cov khoom sib xyaw

Kev txheeb xyuas tshuaj muaj pes tsawg leeg yog txoj hauv kev zoo tshaj plaws rau kev txheeb xyuas cov ntaub ntawv PP, feem ntau suav nrog cov tswv yim xws li infrared spectroscopy, elemental analysis, thiab chromatography.
Infrared spectroscopy (FTIR) yog txoj kev tshuaj ntsuam xyuas feem ntau siv. FTIR tuaj yeem txheeb xyuas cov pab pawg ua haujlwm thiab cov qauv molecular cov yam ntxwv ntawm cov khoom siv, thiab ceev nrooj txheeb xyuas hom PP cov khoom siv hauv paus (homopolymer / copolymer) thiab hom additives los ntawm kev sib piv cov yam ntxwv ntawm kev nqus siab. Tus qauv infrared spectrum ntawm PP qhia plaub lub siab tshaj plaws ntawm 2960-2800 cm⁻¹, sib xws rau C-H stretching vibrations ntawm CH, CH₂, thiab CH₃; ncov ntawm 1460 cm⁻¹ thiab 1376 cm⁻¹ sib haum rau C-H dabtsi yog khoov kev co; lub ncov ntawm 1165 cm⁻¹ sawv cev rau qhov tawm- ntawm lub dav hlau rocking dabtsi yog khoov kev co ntawm methyl pawg; thiab 998 cm⁻¹ band muaj feem xyuam rau 11-13 rov ua dua thiab tuaj yeem siv los ua ib pawg crystalline los xam crystallinity.

Hauv kev sib txawv ntawm cov ntaub ntawv nkauj xwb thiab cov khoom siv rov ua dua tshiab, tus yuam sij rau FTIR yog saib C=O qhov siab tshaj plaws nyob rau hauv thaj tsam 1600-1750 cm⁻¹. Cov kev tshawb fawb tau pom tias PP cov qauv tag nrho pom qhov tsis muaj zog C=O qhov siab tshaj plaws nyob rau hauv cheeb tsam no, uas tej zaum yuav yog vim oxidation ntawm cov khoom siv rov qab los yog muaj cov khoom siv ntxiv uas muaj cov pab pawg ua haujlwm carbonyl. C=O qhov siab tshaj plaws ntawm nkauj xwb PP tsis muaj zog thiab ruaj khov, thaum C=O qhov siab tshaj plaws ntawm cov khoom siv rov ua dua yog qhov muaj zog heev vim yog cov txheej txheem oxidation. Tsis tas li ntawd, ATR-FTIR tseem tuaj yeem kuaj xyuas PE-LD rov ua dua tshiab. Cov khoom siv rov ua dua tshiab tau ua tiav 6 zaug qhia tau tias tus yam ntxwv tshiab methyl ncov (2950.7 cm⁻¹), tab sis lub ncov methyl yam ntxwv tsis pom tseeb hauv cov khoom siv rov ua dua ib zaug, qhia qee qhov kev txwv ntawm txoj kev no.

Cov txheej txheem ua haujlwm rau FTIR tsom xam yog qhov yooj yim. Ua ntej, cov qauv raug txiav rau hauv qhov loj me thiab muab tso rau ntawm ATR (Attenuated Total Reflectance) accessory ntawm Fourier transform infrared spectrometer. Lub scanning ntau yam yog teem rau 4000-400 cm⁻¹, qhov kev daws teeb meem yog 4 cm⁻¹, thiab tus naj npawb ntawm scans feem ntau yog 32. Los ntawm kev sib piv nrog cov qauv spectral tsev qiv ntawv, cov ntsiab lus tseem ceeb ntawm cov khoom tuaj yeem txiav txim siab sai. Rau cov qauv nyuaj, ob-dimensional infrared spectroscopy tuaj yeem siv los txheeb xyuas cov khoom sib txawv los ntawm kev txheeb xyuas cov kev hloov pauv hauv cov spectrum.

Kev tsom xam cov ntsiab lus feem ntau yog siv los txheeb xyuas cov hlau hnyav thiab lwm yam teeb meem hauv cov ntaub ntawv. Khoom noj khoom haus- qib PP muaj cov cai nruj rau cov ntsiab lus hlau hnyav, nrog cov ntsiab lus cadmium Tsawg dua lossis sib npaug li 0.005 mg / kg, cov ntsiab lus mercury tsawg dua lossis sib npaug li 0.01 mg / kg, thiab cov ntsiab lus txhuas tsawg dua lossis sib npaug rau 0.01 mg / kg. Cov txheej txheem kuaj pom feem ntau yog siv inductively txuas nrog ntshav plasma spectrometry (ICP-MS), nrog rau kev kuaj pom qhov txwv ntawm 0.001 mg / kg, lossis atomic absorption spectrometry (AAS).

Elemental tsom xam yog ib txoj hauv kev tseem ceeb rau kev paub qhov txawv ntawm cov nkauj xwb thiab cov khoom siv rov ua dua tshiab. Cov kev tshawb fawb tau pom tias cov ntsiab lus hlau hnyav hauv cov ntaub ntawv nkauj xwb PP yog qhov zoo sib xws, nrog rau qhov sib txawv ntawm qhov sib txawv tsis ntau tshaj 57%, thaum cov ntsiab lus hlau hnyav hauv cov khoom siv rov ua dua feem ntau ntau dua ob qhov kev txiav txim siab ntau dua li cov ntaub ntawv nkauj xwb. Qhov no yog vim cov khoom siv rov ua dua tshiab tuaj yeem cuam tshuam nrog ntau qhov chaw ntawm cov pa phem thaum lub sijhawm rov ua dua tshiab, suav nrog cov khib nyiab hauv tsev thiab cov khib nyiab hauv tsev, ua rau cov hlau hnyav hnyav. Hauv kev sim tiag tiag, yog tias cov ntsiab lus hlau hnyav ntawm cov qauv pom tias muaj qhov txawv txav, feem ntau nws tuaj yeem txiav txim siab ua cov khoom siv rov ua dua lossis cov khoom sib xyaw uas muaj cov khoom siv rov ua dua tshiab.

Kev tshuaj ntsuam chromatographic suav nrog roj chromatography-mass spectrometry (GC-MS) thiab siab-kev ua tau zoo kua chromatography (HPLC), feem ntau yog siv los kuaj cov organic tebchaw, cov seem monomers, thiab additives hauv cov ntaub ntawv. GC-MS tuaj yeem siv los txheeb xyuas cov organic tebchaw tsis zoo thiab cov monomers seem, thaum HPLC yog siv rau kev tshuaj xyuas ntawm tsis yog{5}} tsis hloov pauv hloov pauv hloov pauv. Tshwj xeeb, headspace gas chromatography-mass spectrometry (HS-GC-}MS) thev naus laus zis tau suav nrog hauv lub teb chaws tus qauv GB/T 46019.2-2025, tshwj xeeb rau kev txheeb xyuas cov khoom siv polypropylene.

HS-GC-MS txoj kev suav nrog cov txheej txheem hauv qab no: Nyhav 1.5 g ntawm tus qauv (qhov tseeb rau 0.1 mg) thiab muab tso rau hauv 20 mL headspace vial. Ntxiv 20 μL ntawm D8-naphthalene ua haujlwm tov (0.3 ug / mL) raws li tus qauv sab hauv. Tom qab sib npaug ntawm 150℃rau 30 feeb, ua qhov kev soj ntsuam. Qhov kev tuav pov hwm ntawm txhua qhov tsis muaj zog yog xam los ntawm kev rho tawm lub sijhawm khaws cia ntawm n-alkanes, thiab thaj chaw txheeb ze yog xam los ntawm cov txheej txheem sab hauv normalization ntawm thaj chaw ncov. Cov kws tshawb fawb tau tshuaj xyuas 170 tus qauv PP nkauj xwb thiab 119 cov qauv PP rov ua dua tshiab, tshuaj xyuas 25 yam ntxwv tsis hloov pauv, thiab tsim cov qauv kev txheeb xyuas raws li kev sib tw hav zoov algorithm, nrog qhov tseeb ntawm ntau dua 95%.

2.3 Microstructure thiab Morphology Observation Methods

Kev soj ntsuam microstructure thiab morphology yog ib txoj hauv kev los txheeb xyuas cov ntaub ntawv PP los ntawm qib molecular thiab microscopic morphology foundations, feem ntau suav nrog kev sib txawv scanning calorimetry, polarized light microscopy, thiab scanning electron microscopy.

Differential scanning calorimetry (DSC) tsis tuaj yeem ntsuas cov thermal ua haujlwm tsis zoo ntawm cov khoom, tab sis kuj txheeb xyuas cov khoom siv los ntawm kev txheeb xyuas nws cov yaj thiab crystallization tus cwj pwm. DSC tuaj yeem muab cov yam ntxwv thermal ua haujlwm tsis zoo ntawm cov khoom siv, xws li iav hloov pauv kub, melting point, thiab crystallinity. Cov kev txwv no tseem ceeb heev rau kev paub qhov txawv ntawm cov nkauj xwb thiab cov khoom siv rov ua dua tshiab. Nyob rau hauv kev xyaum, 5-10 mg ntawm cov qauv yog hnyav thiab muab tso rau hauv ib tug txhuas qauv yias, thiab qhov kub thiab txias yog nce los ntawm chav tsev kub mus rau 20℃saum toj no lub melting point ntawm cua kub ntawm 10℃/ min, thiab DSC nkhaus yog kaw.

DSC nkhaus ntawm nkauj xwb PP feem ntau qhia tau hais tias ib leeg, ntse melting ncov nrog ib tug symmetrical zoo, thiab lub melting kub yog nyob nruab nrab ntawm 165-169 degree. Lub DSC nkhaus ntawm cov khoom siv rov ua dua tshiab, txawm li cas los xij, qhia cov yam ntxwv sib txawv: lub siab melting peak widens, ntau melting peaks yuav tshwm sim (xws li, ntawm 132℃thiab 165 degree), lub ncov zoo li asymmetrical, thiab lub melting kub txo. Piv txwv li, hauv ib txoj kev tshawb fawb, cov ntsiab lus melting ntawm cov qauv ntawm # 4 mus rau # 1 poob qis zuj zus, thiab tag nrho cov qis dua 170 degree, thiab crystallinity kuj txo qis zuj zus. Piv txwv #5 kuj tau pom qhov txias crystallization ncov thaum lub sijhawm cua sov, qhia tias cov saw hlau molecular 'mobility tau nce nrog qhov kub thiab txias, thiab cov ntu ntu rov ua dua los ua cov muaju.

Kev suav ntawm crystallinity kuj tseem ceeb rau kev txheeb xyuas. Raws li cov qauv Xc=ΔHm/ΔH0 × 100% (qhov twg ΔHm yog lub melting enthalpy ntawm tus qauv, thiab ΔH0 yog lub melting enthalpy ntawm 100% crystalline PP, 240.5 J / g), crystallinity ntawm cov khoom yuav xam tau. Lub crystallinity ntawm nkauj xwb PP feem ntau yog nyob nruab nrab ntawm 60-80%, thaum lub crystallinity ntawm recycled khoom yuav txo mus rau 40-60% vim yog kev puas tsuaj ntawm molecular saw qauv. Los ntawm kev sib piv cov kev hloov pauv hauv crystallinity, nws tuaj yeem txiav txim siab seb cov khoom puas tau dhau los ua ntau yam txheej txheem. Polarizing microscopy tso cai rau kev soj ntsuam ncaj qha ntawm spherulite morphology thiab qhov loj ntawm PP, yog li txiav txim siab cov yam ntxwv crystallization ntawm cov khoom. Virgin PP, vim nws qhov siab molecular saw tsis tu ncua, tsim cov spherulites nrog kev ua tiav morphology. Recycled PP, txawm li cas los xij, muaj qhov dav dua qhov hnyav molecular faib, ua rau muaj qhov sib txawv ntawm qhov sib txawv thiab cov duab tsis zoo. Tshwj xeeb tshaj yog thaum soj ntsuam qhov tshwm sim ntawm birefringence ntawm spherulites, nkauj xwb PP nthuav qhia meej Maltese ntoo khaub lig extinction qauv, thaum lub sij hawm extinction qauv ntawm recycled PP tej zaum yuav plooj los yog tsis tiav.

Kev tshuaj ntsuam xyuas electron microscopy (SEM) tuaj yeem soj ntsuam qhov chaw morphology thiab hla -sectional qauv ntawm cov khoom. Tus ntoo khaub lig- ntu ntawm nkauj xwb PP qhia txog cov yam ntxwv ntawm cov pob qij txha tsis zoo, lub ntsej muag du, thiab tsis muaj qhov tsis zoo. Tus ntoo khaub lig- ntu ntawm PP rov ua dua tshiab tuaj yeem pom cov yam ntxwv ntawm pob txha tawg, ib qho tawv tawv, thiab ntau yam tsis xws luag xws li voids, tawg, thiab impurities. SEM kuj tseem tuaj yeem siv rau kev tshuaj ntsuam xyuas hluav taws xob dispersive spectroscopy (EDS) txhawm rau txheeb xyuas cov khoom muaj pes tsawg leeg ntawm cov khoom, uas yog qhov tshwj xeeb zoo rau kev txheeb xyuas cov kab mob.

Cov kws tshawb fawb tau siv kev sib xyaw ua ke ntawm kev siv hluav taws xob hluav taws xob hauv hluav taws xob (SEM) thiab lub zog dispersive spectroscopy (EDS) los txheeb xyuas cov morphology thiab elemental muaj pes tsawg leeg ntawm cov qauv, muab cov kev soj ntsuam meej ntawm cov qauv ' microscopic muaj pes tsawg leeg thiab morphology. Txoj kev no tuaj yeem nthuav tawm qhov sib txawv me me uas pom tsis pom ntawm qhov muag liab qab, xws li cov khoom me me impurity, txheej oxide txheej, thiab cov cim ua tiav. Tshwj xeeb tshaj yog rau cov qauv uas muaj me me ntawm cov khoom siv rov ua dua tshiab, macroscopic txoj kev yuav tsis tuaj yeem txheeb xyuas lawv, tab sis SEM-EDS kev tshuaj ntsuam tuaj yeem nthuav tawm cov khoom sib txawv txawv.

3.1 Tus Txheej Txheem Qhia Txog Tus Txheej Txheem Tsim

Raws li peb txoj hauv kev tau piav qhia saum toj no, peb tuaj yeem tsim cov txheej txheem kev txheeb xyuas kom paub meej qhov sib txawv ntawm cov nkauj xwb, siv dua tshiab, thiab cov ntaub ntawv rov qab. Cov txheej txheem no siv peb lub- theem kev txheeb xyuas: "kev tshuaj ntsuam ua ntej - hauv- tsom xam qhov tob - kev txiav txim siab dav".

Qib thib ib: Kev tshuaj xyuas ua ntej. Ua ntej, ua qhov kev soj ntsuam pom thiab ntsuas qhov ntom ntom. High- cov khoom nkauj nkauj zoo nkauj yuav tsum muaj cov qauv zoo nkauj matte, xim ntshiab (feem ntau tawm -dawb los yog translucent), tsis muaj impurities, dub me ntsis, los yog granular xav, thiab tsis muaj pungent tsw. Density testing uses the density gradient column method or an automatic densimeter to compare the sample density with the standard value (0.90-0.91 g/cm³). Yog hais tias tus nqi ceev deviates los ntawm tus qauv ntau tshaj ± 0.005 g / cm³, feem ntau nws tuaj yeem txiav txim siab tias cov khoom tsis yog nkauj xwb.

Nyob rau tib lub sijhawm, qhov ntsuas qhov dej ntws (MFR) tau ua. Tus nqi MFR ntawm nkauj xwb PP yuav tsum nyob rau hauv tus qauv ntau thiab kuj ruaj khov. Yog tias tus nqi MFR yog qhov txawv txav siab (ntau dua ob npaug ntawm tus qauv tus nqi), nws yuav yog cov khoom siv rov ua dua tshiab.

Qib thib ob: Hauv - tsom xam qhov tob. Kev soj ntsuam ntxaws ntxiv yog ua tiav ntawm cov qauv tom qab kuaj ua ntej. Ua ntej, FTIR tsom xam yog ua, tsom rau qhov kev siv ntawm C=O nqus ncov hauv thaj tsam 1600-1750 cm⁻¹. Yog tias C=O ncov tau txhim kho zoo, nws qhia tau tias cov khoom siv tau dhau los ua oxidation thiab yog cov khoom siv rov ua dua tshiab. Tom qab ntawd, DSC tsom xam yog ua los soj ntsuam cov duab, tus naj npawb, thiab qhov kub thiab txias ntawm melting peaks. Yog tias muaj ntau qhov melting peaks tshwm los yog qhov kub ntawm qhov melting qis dua, ua ke nrog kev hloov pauv hauv crystallinity, nws tuaj yeem paub meej ntxiv seb nws puas yog cov khoom siv dua tshiab.

Qib peb: Kev txiav txim siab. Rau cov qauv uas tseem tsis tuaj yeem txiav txim siab, HS-GC- txoj kev MS yog siv rau kev lees paub zaum kawg. Raws li lub teb chaws tus qauv GB / T 46019.2-2025, qhov kev txiav txim yog tsim los ntawm kev tshuaj xyuas 25 yam ntxwv volatile Cheebtsam ua ke nrog ib tug random hav zoov algorithm qauv. Txoj kev no muaj qhov tseeb ntawm ntau dua 95% thiab tuaj yeem paub qhov txawv ntawm cov nkauj xwb PP thiab PP rov ua dua tshiab. Nyob rau tib lub sijhawm, kev tshuaj xyuas cov ntsiab lus yog ua kom pom cov ntsiab lus ntawm cov hlau hnyav. Yog tias cov ntsiab lus ntawm cov hlau hnyav ntau dua li ob qhov kev txiav txim siab ntau dua li qhov qub, nws tuaj yeem txiav txim siab ua cov khoom siv rov ua dua tshiab.
Hauv kev ua haujlwm zoo, nws raug nquahu kom siv ntau txoj hauv kev rau kev sib koom ua ke. For example, first use density and melt flow index for preliminary screening, then use FTIR and DSC for confirmation, and finally use HS-GC-MS for arbitration. Qhov kev sib xyaw ua ke no tuaj yeem zam qhov kev txwv ntawm ib txoj kev thiab txhim kho qhov tseeb ntawm kev txheeb xyuas.

3.2 Kev Txiav Txim Cov Qauv Txheej Txheem

Tsim kom muaj tus qauv txiav txim siab txog kev tshawb fawb yog qhov tseem ceeb los xyuas kom meej qhov tseeb ntawm kev txheeb xyuas. Raws li lub teb chaws cov qauv thiab kev lag luam kev coj ua, peb tuaj yeem tsim cov qauv kev txiav txim hauv qab no.

Lub Cev Muaj Peev Xwm Txiav Txim Siab:

• Qhov ntom: Virgin PP yog 0.905-0.910 g / cm³, cov khoom siv rov ua dua tuaj yeem hloov pauv hauv thaj tsam ntawm 0.900-0.915 g / cm³, thiab cov khoom siv rov ua dua muaj qhov sib txawv ntau dua vim nws txoj kev sib xyaw ua ke.
• Melt Flow Rate (MFR): Tus nqi MFR ntawm nkauj xwb PP yuav tsum nyob rau hauv tus qauv specifications (feem ntau 2-10 g / 10min), tus nqi MFR ntawm cov khoom siv dua tshiab yuav siab dua me ntsis, thiab MFR tus nqi ntawm cov khoom siv rov ua dua yuav yog 2-5 npaug siab dua li cov khoom nkauj xwb.
• Melting Point: Lub melting point ntawm nkauj xwb PP yog 165-169 degree, lub melting point ntawm recycled cov ntaub ntawv tseem tseem tsis tau hloov, thiab lub melting point ntawm recycled khoom yuav txo los ntawm 5-10 degree, thiab ntau melting peaks yuav tshwm sim.
• Crystallinity: Lub crystallinity ntawm nkauj xwb PP yog 60-80%, thiab crystallinity ntawm cov khoom siv dua tshiab yog 40-60%.

Chemical Composition Judgment Criteria:

• FTIR Yam Ntxim Saib Ntxim Ua: C=O peak siv (1600-1750cm⁻¹), tsis muaj zog ntawm cov khoom siv nkauj xwb, muaj zog ntau dua hauv cov khoom siv dua tshiab; methyl yam ntxwv ncov (2950cm⁻¹), tshwm tom qab ntau cov kauj ruam ua.
• Cov ntsiab lus hlau hnyav: Cov ntsiab lus hlau hnyav ntawm cov khoom siv nkauj xwb yog qhov tsawg heev (qhov sib txawv ntawm <57%), thiab cov ntsiab lus hlau hnyav ntawm cov khoom siv rov ua dua tuaj yeem muaj ntau tshaj li ob qhov kev txiav txim siab ntau dua li cov khoom nkauj xwb.
• Cov Cheebtsam tsis zoo: 25 tus yam ntxwv yam khoom raug kuaj pom los ntawm HS-GC-MS, thiab muaj qhov sib txawv tseem ceeb hauv hom thiab cov ntsiab lus ntawm cov khoom nruab nrab ntawm cov khoom siv nkauj xwb thiab cov khoom siv rov ua dua tshiab.

Microstructure Judgement Criteria:

• DSC Melting Peak: Cov khoom siv nkauj xwb qhia tau hais tias ib lub ncov ntse, thaum cov khoom siv rov ua dua tshiab qhia pom qhov dav dav thiab tej zaum yuav muaj ntau lub ncov.
• Spherulite Morphology: Cov khoom siv nkauj xwb muaj qhov sib txawv ntawm qhov loj me thiab ua tiav morphology, thaum cov khoom siv rov ua dua tshiab muaj qhov sib txawv ntawm qhov ntau thiab tsawg thiab cov morphology tsis sib xws.
• Surface Morphology: Tus ntoo khaub lig- ntu ntawm cov khoom nkauj xwb yog du thiab zoo ib yam, thaum tus ntoo khaub lig- ntu ntawm cov khoom siv rov ua dua yog qhov ntxhib thiab tuaj yeem muaj qhov tsis xws luag.

Hauv kev txiav txim siab tiag tiag, ntau qhov ntsuas yuav tsum tau txiav txim siab ua tiav. Piv txwv li, yog tias ib qho piv txwv ua tau raws li cov xwm txheej hauv qab no: qhov ntom ntom hauv cov qauv, tus nqi MFR ib txwm muaj, ib qho melting ncov hauv DSC, tsis muaj zog C=O ncov hauv FTIR, thiab cov ntsiab lus tsis hnyav hlau, ces nws raug txiav txim raws li cov khoom siv nkauj xwb. Yog hais tias tus qauv qhia tau hais tias muaj kev nce ntxiv hauv MFR tus nqi, ntau lub ncov hauv DSC, txhim kho C=O peaks hauv FTIR, thiab cov ntsiab lus hlau hnyav, nws tau txiav txim siab ua cov khoom siv dua tshiab. Rau cov qauv poob ntawm ob qhov siab kawg no, HS-GC-MS tsom xam yog xav tau, ua ke nrog cov qauv hav zoov random rau kev txiav txim zaum kawg.

3.3 Txoj kev txwv thiab cov ntsiab lus tswj kom zoo

Txawm hais tias cov txheej txheem saum toj no muaj qhov raug siab, txhua txoj kev muaj nws cov kev txwv, uas yuav tsum tau xav txog hauv kev siv tswv yim.

• Cov kev txwv ntawm kev ntsuas qhov ntom ntom:Txawm hais tias kev ntsuas qhov ceev yog qhov yooj yim thiab ceev, nws tsuas yog muab cov ntaub ntawv txwv. Qhov ceev ntawm ntau hom PP (xws li homopolymer thiab copolymer) yuav txawv me ntsis, thiab qee cov khoom siv ntxiv (xws li muab tub lim) tuaj yeem cuam tshuam rau tus nqi ceev. Yog li ntawd, kev ntsuam xyuas qhov ceev tsuas yog siv tau raws li kev tshuaj ntsuam xyuas ua ntej thiab tsis tuaj yeem siv los ua lub hauv paus kawg rau kev txiav txim siab.

• Cov kev txwv ntawm melt flow rate testing:Kev ntsuam xyuas MFR cuam tshuam zoo heev los ntawm qhov kub thiab txias keeb kwm, thiab kev hloov me me hauv kev sim ntsuas tuaj yeem ua rau muaj qhov sib txawv ntawm cov txiaj ntsig. Tsis tas li ntawd, qee qhov kev hloov kho (xws li plasticizers) tseem yuav cuam tshuam rau tus nqi MFR. Yog li ntawd, thaum ua kev xeem MFR, cov kev xeem yuav tsum tau tswj nruj me ntsis, thiab yuav tsum tau ua ntau qhov kev xeem sib npaug.
• Kev txwv ntawm FTIR tsom xam:ATR-FTIR txoj kev ua haujlwm zoo rau kev txheeb xyuas PE-LD cov ntaub ntawv siv dua tshiab, tab sis nws muaj kev txwv hauv kev txheeb xyuas cov khoom siv rov ua dua PP, tshwj xeeb tshaj yog cov khoom siv rov ua dua tshiab uas tau dhau los ua ib lub voj voog, uas yuav tsis pom qhov sib txawv loj. Tsis tas li ntawd, FTIR tsuas tuaj yeem muab cov ntaub ntawv ua haujlwm rau pawg thiab tsis tuaj yeem txiav txim siab txog cov qauv tshuaj tshwj xeeb.

Yuav tsum muaj rau HS-GC-MS txoj kev:Txawm hais tias txoj kev no muaj qhov raug siab, nws yuav tsum muaj cov cuab yeej siv tau zoo thiab cov neeg ua haujlwm txawj ntse. Nws yuav tsum muaj lub taub hau roj chromatograph-mass spectrometer nrog EI qhov chaw, lub taub hau qauv ua haujlwm ntawm qhov kub ntawm qhov tsawg kawg nkaus 150 degree, thiab cov kws tshaj lij kev soj ntsuam software thiab zoo- cov neeg ua haujlwm tau txais kev cob qhia.

 

Txhawm rau kom ntseeg tau qhov tseeb ntawm cov txiaj ntsig kev txheeb xyuas, yuav tsum tsim kom muaj kev tswj hwm zoo:

Sample sawv cev tswj:Ua raws li cov qauv coj ua nruj me ntsis (xws li ISO 2859) kom ntseeg tau tias cov qauv coj los ua kom raug cuam tshuam cov yam ntxwv ntawm tag nrho cov khoom siv. Rau cov ntaub ntawv granular, cov qauv yuav tsum tau muab coj los ntawm ntau lub ntsiab lus hauv qhov chaw sib txawv, sib xyaw ua ke, thiab tom qab ntawd sim.

Instrument calibration thiab tu:Tag nrho cov cuab yeej ntsuas yuav tsum tau ntsuas tsis tu ncua. Cov khoom siv hluav taws xob, cov tshuab ntsuas thoob ntiaj teb, thiab lwm yam khoom siv ntsuas yuav tsum tau ntsuas txhua xyoo los ntawm lub chaw ntsuas ntsuas raug cai. Melt flow rate testers thiab heat distortion temperature testers yuav tsum tau calibrated nyob rau hauv -tsev los yog los ntawm ib tug thib peb tog txhua rau lub hlis. Cov khoom calibration muaj xws li kub qhov tseeb, quab yuam tus nqi raug, thiab tus nqi stability. Calibration cov ntaub ntawv yuav tsum tau muab khaws cia rau yav tom ntej siv los xyuas kom meej cov traceability ntawm cov ntaub ntawv xeem.

Environmental condition tswj:Qhov chaw sim yuav tsum ua tau raws li cov qauv kev cai, vim tias qhov kub thiab txias, av noo, thiab kev huv huv tuaj yeem cuam tshuam tag nrho cov txiaj ntsig kev xeem. Piv txwv li, kev ntsuas qhov ceev yuav tsum muaj qhov ntsuas kub tsis tu ncua ntawm 23 ± 0.5 degree; FTIR tsom xam yuav tsum tau ua nyob rau hauv ib qho chaw qhuav kom tsis txhob muaj dej vapor cuam tshuam; thiab kuaj microbiological yuav tsum tau ua hauv chav huv.

Cov ntaub ntawv thiab traceability:Tag nrho cov txheej txheem xeem thiab cov txiaj ntsig yuav tsum tau sau tseg kom ntxaws, suav nrog cov ntaub ntawv coj mus kuaj, kuaj mob, cov ntaub ntawv nyoos, txheej txheem suav, thiab cov txiaj ntsig kawg. Cov ntaub ntawv yuav tsum meej, meej, traceable, thiab khaws cia rau lub sijhawm teev tseg.

Los ntawm kev tsim kom muaj kev tswj xyuas kev ua tau zoo, qhov zoo ntawm ntau txoj kev txheeb xyuas tuaj yeem ua kom tiav, kom ntseeg tau tias qhov sib txawv ntawm cov nkauj xwb, rov ua dua tshiab, thiab rov ua dua tshiab - qib PP yas raw cov ntaub ntawv, muab kev txhawb nqa zoo rau kev tswj xyuas cov khoom zoo. Hauv kev siv tswv yim, kev sib xyaw ua ke tsim nyog yuav tsum raug xaiv raws li qhov xwm txheej tshwj xeeb, kom ntseeg tau tias qhov tseeb thiab txiav txim siab cov nqi ntsuas thiab kev ua haujlwm zoo. Rau cov zaub mov - qib PP, cov khoom siv uas muaj kev nyab xeeb siab heev, nws raug nquahu kom siv ntau txoj hauv kev rau kev qhia paub meej kom paub meej cov khoom zoo thiab kev nyab xeeb ntawm zaub mov.