Rapid Ring‐Opening Polymerization of D,L‐Lactide by Microwaves

Abstract

Summary: Poly(D,L‐lactide) with a molar mass of 105 g · mol−1 and a yield over 90% was produced in 10 min by the ring‐opening polymerization of D,L‐lactide under microwave irradiation with forward power of 255 W. A degradation of the poly(D,L‐lactide) was also induced by microwaves with a power level over 340 W. The molar mass of poly(D,L‐lactide) was dependent upon the competition between the polymerization of D,L‐lactide and the degradation of the resulting polymer.Profiles of molar mass versus microwave irradiation time (1.8 g DLLA, 0.1% Sn(Oct)2).magnified imageProfiles of molar mass versus microwave irradiation time (1.8 g DLLA, 0.1% Sn(Oct)2).

Synthesis and processing of biodegradable and bio-based polymers by microwave irradiation

“…Optimal results were achieved setting the power level at 255 W, while reactions carried out at 340 W or more showed a significant degradation of the product (C. Zhang et al, 2004). According to other authors, the reaction rate in the ROP of L-lactide increases linearly with power output (tested up to 1,300 W), though molecular weights (and consequently degradation phenomena) were not monitored for P(L)LA (Koroskenyi & McCarthy, 2002).…”

Microwave-Assisted Biocatalytic Polymerizations

“…They reported that efficient heating using microwave resulted in successful polymerization without the need for vacuum or inert atmosphere (32). Liu and coworkers investigated the microwave assisted polymerization of lactide emphasizing on the effect of microwave power on polymerization process (31). They concluded that, up to 255 W the molecular weight of the polymer increased and reached a maximum when approximately 90% conversion was reached ( Figure 4) (31).…”

Microwave‐Assisted Single‐Step Synthesis of Poly(alkylene hydrogen phosphonate)s by Transesterification of Dimethyl Hydrogen Phosphonate with Poly(ethylene glycol)

“…[7][8][9][10][11] Some polymerization reactions are significantly improved under microwave irradiation and the microwave-assisted preparations of biodegradable polymers have also been studied. [12,13] Poly(alkylene hydrogen phosphonate)s are a relatively new family of biodegradable polymers. Polymers of this type with molecular weights ranging between 2 000 and 5 000 Da have been actively investigated in the last few years, mainly for various biomedical applications.…”