Poly(p-dioxanone) (PPDO) has received significant attention due to its good biocompatibility and fast biodegradation profiles. In addition, PPDO is a polymer with high potential in biomedical applications. However, the conventional syntheses of PPDO via the ring-opening polymerization (ROP) of p-dioxanone (PDO) often use a metallic catalyst, which significantly limits its biorelated applications. This investigation was focused on the synthesis of metal-free PPDO by using phosphazene base t-BuP₄ as the catalyst. The effects of the reaction conditions including temperature, reaction time, initiators, and feed molar ratios were studied in detail by nuclear magnetic resonance spectroscopy, viscosimetry, differential scanning calorimetry, and thermogravimetric analysis. The results showed that t-BuP₄ exhibited especially high activity in catalyzing alcohol or aniline to initiate the ROP of PDO, consequently resulting in metal-free PPDOs. The polymerization was optimum at a reaction temperature of approximately 100°C and 88.7% of PDO was consumed. The viscosity–average molecular weights of the resulting polymer reached as high as 2.09 × 10⁴ g/mol. The molar ratios of [PDO]/[t-BuP₄] also had an obvious effect on both the polymerization and the resulting polymer. Increasing [PDO]/[t-BuP₄] ratios facilitated the molecular weight growth, whereas the conversions of PDO significantly decreased. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43030.

Polymers bearing pendant vinyl groups have attracted significant attraction because they can be further modified for required applications, but their syntheses are still a big challenge. Herein, allyl methacrylate was catalyzed using a phosphazene base to homopolymerize or copolymerize with 2-(N, N-dimethylamino) ethyl methacrylate, affording vinyl functional polymers, which were further successfully tailored by the thiol–ene coupling reaction. The result showed that both the homopolymerizations and copolymerizations could proceed at room temperature with very high monomer conversions. The contents of pendant double bonds in the copolymers were approximately equal to the monomer feeds, but the LCST of the statistical copolymers linearly decreased with increasing AMA content. This strategy offered a new scalable and facile strategy for vinyl functional polymers, would have a wide practical application in many fields. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42758.

Ultrafast preparation of branched poly(methyl acrylate) (BPMA) with high-molecular weight through single electron transfer living radical polymerization (SET-LRP) of inimer at 25°C has been attempted, atom transfer radical polymerization (ATRP) at 60°C was also carried out for comparison. Gas chromatography, proton nuclear magnetic resonance, and triple detection size exclusion chromatography were used to analyze these polymerizations. As expected, SET-LRP system showed much faster polymerization rate than ATRP system, the calculated apparent propagation rate constants (k_p^app) are 3.69 × 10⁻² min⁻¹ and 6.23 × 10⁻³ min⁻¹ for SET-LRP and ATRP system, respectively. BPMA with high-molecular weight (M_w._MALLS = 86,400 g mol⁻¹) compared with that in ATRP (M_w.MALLS = 61,400 g mol⁻¹) has been prepared. POLYM. ENG. SCI., 54:1579–1584, 2014. © 2013 Society of Plastics Engineers

Heat-resistant branched poly(styrene-alt-NPMI) has been prepared via atom transfer radical polymerization (ATRP) of styrene (St) and N-phenyl maleimide (NPMI) with divinylbenzene (DVB) as the branching agent in anisole at 80°C. Gas chromatography (GC) was used to determine the conversion of the reactants. Triple detection gel permeation chromatography (TD-GPC) was used to analyze the copolymers. The results show that the polymerization yields primary chains predominately in the early stages and the formation of branched molecules occurs mainly when conversion is higher than 50%. As expected, higher dosage of DVB in our investigation range favors the formation of polymers with higher degree of branching. All the resulting branched poly(styrene-alt-NPMI)s have glass transition temperature (T_g) above 175°C, extrapolated initial weight loss temperature (T_i) above 410°C and statistic heat-resistant index above 200°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011