Synthesis of Block Copolymers of Ethylene with Styrene and <i>n</i>-Butyl Acrylate via a Tandem Strategy Combining Ethylene “Living” Polymerization Catalyzed by a Functionalized Pd−Diimine Catalyst with Atom Transfer Radical Polymerization
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Bibliographic record
Abstract
We report a new two-step tandem strategy combining two versatile “living” polymerization techniques, Pd−diimine catalyzed ethylene “living” polymerization and atom transfer radical polymerization (ATRP), for the synthesis of functionalized polyethylene (PE) diblock copolymers containing an ethylene block and a functional monomer block, such as styrene and n -butyl acrylate. The key to the success of this tandem strategy is the development of a novel functionalized Pd−diimine catalyst, [(ArN C(Me)−(Me)C NAr)Pd(CH 2 ) 3 C(O)O(CH 2 ) 2 OC(O)C(CH 3 ) 2 Br] + SbF 6 - (Ar = 2,6-( i Pr) 2 C 6 H 3 ) ( 3 ), which uniquely contains a 2-bromoisobutyryl substituting group on its chelate structure. This catalyst was synthesized by convenient equimolar reaction of the acetonitrile Pd−diimine adduct, [(ArN C(Me)−(Me)C NAr)Pd(CH 3 )(N⋮CMe)] + SbF 6 - (Ar = 2,6-( i Pr) 2 C 6 H 3 ) ( 1 ), with a functional acrylate monomer, 2-(2-bromoisobutyryloxy) ethyl acrylate (BIEA). The remarkable feature of 3 lies in its unprecedented ability to catalyze ethylene “living” polymerization that directly gives rise to telechelic PE chains bearing an end-capping 2-bromoisobutyryl group active for initiating ATRP. The resulting end-functionalized PEs can thus be directly used as macroinitiators to subsequently initiate ATRP of functional monomers, like styrene and n -butyl acrylate used in this work, in the second step of this tandem strategy to synthesize functionalized diblock copolymers. Because of the “living” polymerization nature of both steps in this tandem strategy, we demonstrate that the functionalized block copolymers synthesized possess well-defined structures with narrow molecular weight distributions and controllable lengths for both PE and functional monomer blocks.
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Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it