2,3,4,6-Tetra-O-methyl-d-galactonic acid (5) was readily prepared from d-galactono-1,4-lactone (1) in 47% yield. The sequence involves tritylation of HO-6 of 1, followed by O-permethylation and deprotection. Lactonization of 5 led to the per-O-methyl-d-galactono-1,6-lactone, which was copolymerized with epsilon-caprolactone by ring-opening polymerization catalyzed by scandium triflate. The inco...

The effect of configuration of an asymmetric bulky initiator 2,2’-[1,1’-binaphtyl-2,2’-diyl10 bis-(nitrylomethilidyne)]diphenoxy aluminum isopropoxide (Ini) on structure of copolymer of 11 asymmetric monomer L,L-lactide (Lac) with symmetric comonomer trimethylene carbonate (Tmc) 12 was studied using polarimetry, dilatometry, SEC and 13C NMR. When the S-enantiomer of Ini was 13 used the distribu...

To evaluate chemical compositions and heterogeneity of comonomer sequences in methyl methacrylate (MMA)-tert-butyl methacrylate (TBMA) copolymers, multivariate analysis was applied to the 13C nuclear magnetic resonance (NMR) spectra of the carbonyl, backbone quaternary and a-methyl carbons of the copolymers. A better linear relationship was found between the first principal component score and ...

We report a fabrication method for a gradient refractive-index polymeric object from a binary comonomer system, regardless of the monomers' reactivity ratio and the molar volume criteria of gradient refractive-index development. To fabricate a large gradient refractive-index rod consisting of a methyl methacrylate and 2,2,3,3-tetrafluoropropyl methacrylate comonomer pair that has not been used ...

Although the concept of structural water that is bound inside hydrophobic pockets and helps to stabilize protein structures is well established, water has rarely found a similar role in supramolecular polymers. Water is often used as a solvent for supramolecular polymerization, however without taking the role of a comonomer for the supramolecular polymer structure. We report a low-molecular wei...

Poly(methacrylic acid-g-ethylene glycol) (P(MAA-g-EG)) has been studied extensively in our laboratory due to its extremely promising applications in the biomedical and pharmaceutical fields. It exhibits pH-responsive interpolymer complexes that make it a promising candidate as an oral carrier for peptide and protein drug. We have developed a photoinitiated free-radical precipitation polymerizat...

A series of N-acetyl-O-(ω-alkenyl)-L-tyrosine ethyl esters were synthesized by the reaction of vinyl bromides (4-bromo-1-butene, 6-bromo-1-hexene, 8-bromo-1-octene and 10-bromo-1-decene) with N-acetyl-L-tyrosine ethyl ester. 1H NMR, elemental analysis, FT-IR, and mass spectra were performed for these N-acetyl-O-(ω-alkenyl)-L-tyrosine ethyl esters. The novel titanium complex can catalyze the cop...

Control of copolymer composition and molecular weight distributions is important, since they partially govern material performance. This work uses a simple but robust approach to approximate predictive control of average composition and molecular weight during free radical copolymerization, based on detailed kinetics obtained by ACOMP (automatic continuous online monitoring of polymerization re...

It is estimated that 60 to 70% of LLDPE enters the market as blends (Utracki 1989a), primarily with other members of the polyolefin family, e.g., LDPE or polypropylene (PP). Despite the long history of polyethylene (PE) blending and its widespread use, many questions about the homogeneity of such blends, with obvious implications for thermodynamics and for the rheology, are still not answered t...