Alpha-olefin interpolymers with improved molecular design for photovoltaic encapsulants

A solution polymerization process to prepare an ethylene/alpha-olefin/interpolymer that comprises the following properties:

• a) a total unsaturation/1000C≥0.30;
• b) a molecular weight distribution (MWD)≤3.0;
• c) a thermal gradient interaction chromatography (TGIC) broadness parameter B1/4≤8.0;
• said process comprising polymerizing, in one reactor, at a reactor temperature ≥150° C., a reaction mixture comprising ethylene, an alpha-olefin, a solvent, and a metal complex selected from a) below:
• a) a biphenyl phenol metal complex selected from the following Structure 1:
• M is Zr or Hf, the metal being in a formal oxidation state of +2, +3, or +4;
• n is 0, 1, or 2;
• when n is 1, X is a monodentate ligand or a bidentate ligand;
• when n is 2, each X is an independently chosen monodentate ligand;
• the metal complex is overall charge-neutral;
• each of —Z1— and —Z2— is independently selected from —O—, —S—, —N(RN)—, or —P(RP)—;
• R1 and R8 are independently selected from the group consisting of —H, (C1-C40)-hydrocarbyl, (C1-C40)heterohydrocarbyl, —Si(RC)3, —Ge(RC)3, —P(RP)2, —N(RN)2, —ORC, —SRC, —NO2, —CN, —CF3, RCS(O)—, RCS(O)2—, (RC)2C═N—, RCC(O)O—, RCOC(O)—, RCC(O)N(R)—, (RC)2NC(O)—, halogen, radicals having formula (I), radicals having formula (II), and radicals having formula (III):
• where each of R31-35, R41-48, and R51-59 is independently selected from (C1-C40)hydrocarbyl, (C1-C40)heterohydrocarbyl, —Si(RC)3, —Ge(RC)3, —P(RP)2, —N(RN)2, —N═CHRC, —ORC, —SRC, —NO2, —CN, —CF3, RCS(O)—, RCS(O)2—, (RC)2C═N—, RCC(O)O—, RCOC(O)—, RCC(O)N(RN)—, (RC)2NC(O)—, halogen, or —H;
• each of R2-7, R9-16 is independently selected from (C1-C40)hydrocarbyl, (C1-C40)heterohydrocarbyl, —Si(RC)3, —Ge(RC)3, —P(RP)2, —N(RN)2, —N═CHRC, —ORC, —SRC, —NO2, —CN, —CF3, RCS(O)—, RCS(O)2—, (RC)2C═N—, RCC(O)O—, RCOC(O)—, RCC(O)N(RN)—, (RC)2NC(O)—, halogen, or —H;
• L is (C1-C40)hydrocarbylene or (C1-C40)heterohydrocarbylene, wherein the (C1-C40)hydrocarbylene has a portion that comprises a 1-carbon atom to 10-carbon atom linker backbone, linking the two Z groups in Structure 1 (to which L is bonded);
• or the (C1-C40)heterohydrocarbylene has a portion that comprises a 1-atom to 10-atom linker backbone, linking the two Z groups in Structure 1, wherein each of the 1 to 10 atoms of the 1-atom to 10-atom linker backbone of the (C1-C40)heterohydrocarbylene, independently, is a carbon atom or heteroatom group, wherein each heteroatom group independently is O, S, S(O), S(O)2, Si(RC)2, Ge(RC)2, P(RC), or N(RC);
• and each RC, RP, and RN in Structure 1 is independently a (C1-C30)hydrocarbyl, a (C1-C30)heterohydrocarbyl, or —H.