DEVOLATILIZATION OF ETHYLENE/a-OLEFIN COPOLYMER PELLETS

A process for devolatilization of ethylene/α-olefin copolymer pellets, wherein the ethylene/α-olefin copolymer has a VICAT softening temperature (VSP) measured by ASTM D1525-17 and a highest peak melting temperature Tm, wherein the process comprises:

• a) filling a devolatilization bin at a filling time tf with the ethylene/α-olefin copolymer pellets, wherein the ethylene/α-olefin copolymer pellets are characterized by containing greater than or equal to 1 weight % of residual volatile hydrocarbons;
• b) providing nitrogen gas to the devolatilization bin at a first nitrogen inlet temperature (TNinlet)1 for a first period of time t1 subsequent to the filling time tf, wherein (TNinlet)1 is greater than VSP−30° C. and less than the VSP of the ethylene/α-olefin copolymer and wherein the first period of time t1 is sufficient to form a new peak melting temperature Tm1 in the ethylene/α-olefin copolymer, wherein Tm1 is greater than (TNinlet)1 and less than the highest peak melting temperature Tm;
• c) raising and holding the nitrogen gas temperature provided to the devolatilization bin at a second nitrogen inlet temperature (TNinlet)2 for a second period of time t2 subsequent to the first period of time t1, wherein (TNinlet)2 is greater than (TNinlet)1 and less than Tm1;
• and
• d) discharging the ethylene/α-olefin copolymer pellets from the devolatilization bin at a third period of time t3 subsequent to the second period of time t2;
• wherein the ethylene/α-olefin copolymer pellets contain less than or equal to 150 parts per million of the residual volatile hydrocarbons after a holdup time (HUT) corresponding to sum of the filling time in the step a), the first period of time t1 in the step b), the second period of time t2 in the step c) and the third period of time t3 in the step d).