Functional Polymers from Renewable Resources: Itaconic and Lactic Acids

Samuel J. Huang and R. A. Weiss (University of Connecticut), DMR-0328002

Biodegradable polymers based on renewable resources such as itaconic anhydride (ITA), lactic acid (LA) and stearyl methacrylate (SM), can be designed for biomedical, coating and blend applications. We expect that the addition of polar functionality, specifically, ionic groups, will significantly improve their heat resistance and mechanical properties, as well as introduce polarity that may make them suitable for new applications. Two types of ionomers, telechelic and random ionomers are being synthsized. The ionomers exhibited ionic aggregation, as evidenced by a SAXS peak at q = 1.5 nm-1 (d ~ 4 nm), see Fig. 1. The ionic aggregates act as physical cross-links, which increase the Tg and improve the mechanical properties above Tg,see Fig. 2. The Tg of telechelic PLA-ITA copolymers was improved by converting the ITA end-group to a metal carboxylate, see Fig. 3.

Fig. 2. Thermomechanical analysis the polymers shown in Fig. 1

O

H2C

CH2

O

O

C

CH3

C

OCH2

O

H2CO

nm

CH

H2C

CH3

O

O

x

CCH3

O

q/a

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8

Tg

(o C)

25

30

35

40

45

50

55c = 0.6 mol%

(M ~ 13,000 g/ mole)

c = 2.1 mol%M ~ 3,000 g/ mole

H2C C

H2C C

O

OO

R'

O

O

O

NaNa

Fig. 3. Tg vs. charge/ion radius for PLA-ITA telechelic ionomers

YZnCaLiNaK

Fig. 1. SAXS for poly(ITA-co-SM (40% ITA and random ionomers

Functional Polymers from Renewable Resources: Itaconic and Lactic Acids

Samuel J. Huang and R. A. Weiss (University of Connecticut), DMR-0328002

Education

This grant supports three graduate students: Ms. Shurui Shang, 3rd year Ph. D. student Mr. Andrew Ro, 2nd year Ph. D. student Ms. Mojun Liu, M.S. degree in 2004.and 1 REU student (under-represented minority): Mr. Ebenizer Donkoh

Publications

• S.J. Huang and J.A. Wallach, Functional Polymers from Itaconic Anhydride, Polym. Prepr. 45, (2004)

• S Shang, R.A. Weiss and S.J. Huang, Synthesis of Biodegradable Polymers from Itaconic Anhydride and Stearyl Methacrylate, Polym. Prepr. 46(1), 337(2005)

Presentations

Our results have been presented at:

• American Chemical Society National Meeting, Fall 2004, Philadelphia, Symposium on Bio-related polymers.

• American Chemical Society National Meeting, Spring 2005, San Diego, Symposium on Biodegradable Polymers and Materials.

•American Chemical Society 2nd Int'l Conference on Green and Sustainable Chemistry and 9th Annual Green Chemistry and Engineering Conference, June 2005, Washington D. C., and 10th Annual Green Chemistry and Engineering Conference, June 2006, Washington D. C.

• Annual Symposium of the New England Green Chemistry Consortium, 2006, Orno, ME.

Outreach

A research collaboration was begun with Prof. Tom Filburn of the Mechanical Engineering Dept. at the Univ. of Hartford, a predominantly undergraduate institution. Prof. Filburn lacks adequate research facilities and graduate students to carry out his research on CO2 capture for space vehicles. We provided him with laboratory space at UConn, share a graduate student with him and providing him with help on polymer chemistry. My students have interacted with him and his undergraduate students at UConn and at the U. Hartford .