Hpa majaw nga yang, n-gun kaba ai -n-gun n law ai polyethylene (HP-LDPE, LDPE ngu nna kadun ai hku tsun ai) hpe bungli galaw ai gaw shaning 70 jan rai sai raitim, olefin polymerization catalysts hpe mu tam nna galaw shapraw ai majaw, polyethylene a amyu myu hte pru wa ai lam gaw grai law wa sai. Raitim, n-gun kaba ai-polyethylene gaw ahkyak ai shara hpe naw hkam la nga ai. Ethylene hpe n-gun kaba ai n-gun hte n-gun kaba ai npu hta free radical ladat hku nna molecular n-gun kaba ai polyethylene de polymerized galaw nna, lawu na arawn alai ni hpe hkam la lu ai:
(1) Ethylene polymerization galaw ai lam gaw n-gun ja ai exothermic galaw ai lam re. Ethylene a n-gun gaw 93.5kJ/mol (sh) 3.3kJ/g daram rai nna, 235MPa hte 150~300℃hta ethylene a n-gun atsam gaw 2.51~2.85J/(g·℃) daram rai nga ai. 1% ethylene hpe Polymerization galaw ai shaloi, nbung hpe 12 kaw nna 13℃du hkra jat wa shangun na re. N-gun grai ja ai rai yang, ethylene hpe mung n-gun yawm mat shangun na re.
(2) N-gun kaba ai npu hta, ethylene hpe nbung n shang hkra 0.5g/mL density hte shinggrup da ai rai nna, dai gaw n shinggrup lu ai ntsin hte bung ai. Ndai aten hta, ethylene molecule ni a lapran na tsan gang ai lam hpe grai shayawm kau ai majaw, free radicals hte ethylene molecule ni law wa ai. Hkrum katut ai lam gaw grai law ai majaw, polymerization byin wa na masa nga ai.
(3) N-gun ja ai shara hta rawt jat wa ai n-gang a free radical shamu shamawt lam gaw kaba ai, n-gang htawt sit ai lam byin wa na masa nga ai, lu la ai polymer gaw n-gang grau law ai linear structure nga ai. Ga law malawng carbon chain atom 1000 hta branch 20-30 lawm nna, n-gun 45%-65%, n-gun 0.910-0.925g/mL, n-gun n law ai, n-gun n law ai, n-gun n law ai hte hkra machyi ai lam ni hpe hkam sharang lu ai.