Inverse Design of Molecular Weight Distribution in Controlled Polymerization via a One-Pot Reaction Strategy

Abstract

Synthesizing polymers with tailor-made molecular weight distribution (MWD) is an essential step toward better control and design of functional polymer materials. We propose a novel one-pot reaction strategy that can facilitate the inverse design of the shape, breadth, and skew of the MWD in a controlled polymerization. By a multistep initiator addition scheme that involves a sequence of addition operations with determined amounts of initiators and addition times, the polymers with target MWD can be possibly synthesized. This strategy is in principle suitable to reproduce most target MWDs, even with a multimodal profile or with large breadth and/or skew. As compared to previous relevant methods by blending polymers with determined molar masses and ratios, this one-pot reaction strategy avoids most of the tedious intermediate steps for controlling precision in blending and would be more convenient and timesaving. Our study supplies the inspiration of better control of synthesizing polymers with designated MWD in controlled polymerization.

Controlling the shape of the molecular weight distribution for tailored tensile and rheological properties in thermoplastics and thermoplastic elastomers

“…In principle, by shifting the LAM phase boundary toward higher volume fractions of hard block, one would enable the production of remarkably stiff, strong, and tough TPEs without compromising their elastomeric properties. Given the numerous accounts that have reported tuned phase behavior through varying block dispersity, 26–42,45,74–76 we sought to influence phase behavior and thereby tensile properties through controlling MWD skew.…”

“…On this basis, a variety of methods for gaining synthetic control over polymer MWDs have been developed 15–46 . Although the majority of early methods only afforded control over the relative breadth of the MWD, a limited number for controlling the entire MWD have been reported.…”

“…More recently, Boyer and co‐workers demonstrated control over polymer MWDs by altering the flow rates of a continuous flow PET‐RAFT system, 20–22 and similarly, Junkers and co‐workers independently developed an automated continuous flow radical RAFT process to tune the dispersity and shape of the MWD 23,24 . Notably, several recent mathematical models have also been developed to predictively synthesize tailored MWDs 21,23,24,36,39,40,43,44 …”

Precise Control of Both Dispersity and Molecular Weight Distribution Shape by Polymer Blending

“…Although low dispersity polymers ( Đ <1.20) were initially the preferred target for polymer chemists, [10–12] it has recently been demonstrated that moderate ( Đ =1.20–1.50) and high dispersity ( Đ >1.50) materials are equally desirable and exhibit complementary properties and characteristics [7, 13–16] . This has resulted in the development of various chemistry and engineering methods to target different dispersity values and to tailor MWD shapes [3, 8, 17–22] …”

Tailoring polymer dispersity by mixing ATRP initiators

“…14,16,17 Other noticeable examples include blending approaches, 9,18 data encryption via MWD fingerprints developed by the Junkers group, [19][20][21][22] and the use of elegant flow chemistry methods employed by the groups of Frey, Boyer, Leibfarth, Guironnet, and Lu. [23][24][25][26][27][28][29] The vast majority of these methodologies include the design of suitable equations and modelling systems to precisely tailor MWDs and provide polymers with a high range of Ɖs.…”