Novel functional poly(P-hydroxyalkanoates), PHAs, with hyperpolarizable side groups were prepared. Pseudomonas oleovorans ATCC 29347 and Pseudomonas putida KT 2442 were selected as biocatalysts. These organisms were first grown on citrate (40 mM) before polymer formation was studied in a second stage. The carbon sources in second-stage cultivations were mixtures (total of 15 mM) of octanoate (OA) with either 7.5 or 10 mMpara-cyanophenoxyhexanoate (CPH), para-cyanophenoxyvalerate (CPV), para-cyanophenoxybutyrate (CPB), or para-nitrophenoxyhexanoate (NPH). For both organisms, only small deviations in the number of colony-forming units per millilitre were observed when second-stage cultivations containing only 15 rnM octanoate were compared with those using mixtures of OA with either CPB, CPV, CPH, or NPH. PHA volumetric yields as a function of organism, carbon source mixture, and culture time are reported. The percent incorporations of substituted phenoxy side groups in the polymer products were determined by 'H NMR spectroscopy. Pseudomonasputida formed PHAs with up to 24.2% 3-hydroxy-6-(para-cyanophenoxy)hexanoate side groups when 5 mM OA and 10 mM CPH were used. A dramatic decrease in the percent incorporation of para-cyanophenoxy (CP) by P . putida was observed when the relatively shorter CP-substituted n-alkanoate chain CPV and CPB cosubstrates were used. Use of NPH in place of CPH had deleterious effects on both polymer formation and percent incorporation of substituted phenoxy side groups in P. putida. Pseudomonas oleovorans formed PHAs with only up to -2% CP side chains when a combination of OA and CPH was used and little to no CP side groups when a combination of OA and CPV or CPB was used. Substitution of NPH in place of CPH led to a modest increase (up to -5%) in substituted phenoxy side groups. Thus, a new route to first-generation chiral polymer structures for nonlinear optical applications was demonstrated.

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A simple strategy was developed based on a new reactive function-and a salt-containing new monomer, 4-vinylbenzyl dimethyl 2-(dimethylphosphino)ethyl phosphonium chloride (VDEPC), to obtain stable humidity-sensitive membranes. The major ingredient of a humid membrane is crosslinked polyelectrolytes obtained from copolymers of VDEPC/2-ethylhexyl acrylate (2-EHA) ϭ 1/0, 4/1, and 2/1. Isothermal humidity absorption experiments were performed for the estimation of humidity-sensing materials. The crosslinked copolymers prepared from the reaction of VDEPC/2-EHA ϭ 4/1 with 1,4-dichlorobutane showed an average impedance of 595, 39.1, and 3.9 K⍀ at 30, 60, and 90% RH, respectively. Their hysteresis, temperature dependence, frequency dependence, and response time were measured. The reliability including water resistance and a longterm stability were estimated for the application of the common humidity sensor.

The preparation of novel fluorinated poly(β-hydroxyalkanoates), PHAs, was carried out using Pseudomonas oleovorans (ATCC 29347) and Pseudomonas putida (KT 2442) as biocatalysts. These organisms were first grown on 40 mM sodium citrate prior to studying polymer formation in the second stage using 1:1 molar mixtures of nonanoic acid (NA) and fluorinated acid cosubstrates. The following fluoro acids were synthesized and used in this study:  6,6,6-trifluorohexanoic acid (TFHxA), 6,6,7,7,8,8,8-heptafluorooctanoic acid (HpFOA), 6,6,7,7,8,8,9,9,9-nonafluorononanoic acid (NFNA), and 6,6,7,7,8,8,9,9,10,10,11,11,11-tridecafluoroundecanoic acid (TDFUDA). In general, the use of NA/fluoro acid cosubstrate mixtures instead of only NA in second-stage cultivations resulted in little to no cellular toxicity as measured by values of colony-forming units per milliliter. The mol percent incorporations of fluorinated side chains was determined by 1H and 19F NMR spectroscopies, and peak assignments were made using two-dimensional reverse-detected heteronuclear multiplet quantum correlation (HMQC) as well as 1H−H correlation spectroscopy (COSY). P. putida formed PHA after a 3-day second-stage cultivation time with 17.3 mol % fluorinated side chains using NA/NFNA as cosubstrates. For shorter second-stage cultivation times (1 day) where product yields were relatively higher, 0.3 g/L of product was formed that contained 6.4 mol % fluoroalkanoate side groups using P. oleovorans as the biocatalyst and NA/HpFOA as cosubstrates. The incorporation of 12.4 mol % fluoroalkanoate repeat units resulted in products which showed melting at higher temperatures (55−80 °C), crystallized at faster rates from the melt, and had higher heats of fusion. Investigation of the surface free energy of products by surface contact angle measurements showed only a modest increase from 87 to 94° for PHAs containing 0 and 17.3 mol % fluorinated side chains.

The rheological properties of Bis‐GMA dispersions filled with fumed silica were investigated to optimize the manufacturing process and mechanical properties by using a Rheometrics Mechanical Spectrometer (RMS). Steady and dynamic measurements on the RMS were carried out to obtain shear viscosity and dynamic mechanical properties. The effect of several factors on the rheological properties of fumed silica dispersions was also examined. The factors were a concentration of a silane coupling agent (γ‐MPS), the methods of surface treatment of fillers, silica content, diluent concentration, shear rate, and operating temperatur. From these studies, it was observed that shear viscosity showed an asymptotic phenomenon at a higher concentration than a uniform multi‐layer coverage concentration of γ‐MPS. The silane coupling agent had a significant role in the reduction of tan δ, resulting from a decrease of loss modulus, while fillers decreased tan δ by increasing the storage modulus. In cases where the silica content and diluent concentration increased simultaneously, the Barcol hardness of Bis‐GMA/silica composites was increased, but there was no change in the viscosity of dispersions and diametral tensile strength of those composites.