This study presents an investigation on polyimides derived from a unfunctionalized symmetric cyclopentyl-containing alicyclic cardo-type dianhydride with ester linkage 1,1-bis(4-(3,4-dicarboxylbenzoyloxy)phenyl)cyclopentylene dianhydride (BDPCP) that was readily accessed starting from cyclopentanone through two steps in high yield. Two series of polyimides, Cardo-type series (CPI-x) and analogous aromatic series (ArPI-x) were prepared from condensation of BDPCP and aromatic 3,3′,4,4′-Oxydiphthalic dianhydride with four aromatic diamines, respectively. Comparative studies revealed that CPI polymers show more favorable properties including better solubility in organic solvents, higher transparency with lower cut-off wavelength (λ₀) ranging in 395–375 nm than 425–405 nm, lower water absorption ranging in 0.66–1.14% and surface energy 23.71–32.77 mN/m than 1.01–1.28% and 29.52–41.99 mN/m of ArPI analogs. Meanwhile, CPI series exhibit considerable mechanical properties with tensile strengths ranging in 87.6–102.9 MPa, elongations at break 6.6–8.9%. Owing to the moderate strain in cyclopentyl ring, CPI series retain good thermal properties with the glass transition temperature (T_g) in the range of 217–271°C. Dynamic dielectric measurement revealed that Cardo-type dianhydride BDPCP endows CPI-4 film with lower dielectric constant (ε′) 3.34 at 1 MHz and 25°C and dielectric loss (ε′′) 0.0064 at 1 kHz and 25°C than 3.49 and 0.013 for ArPI-4 film. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42670.

In this article, a new alicyclic-functionalized diamine, 1,3-bis(4-aminophenoxymethylene)-1,2,2-trimethylclopentane (BAMT) was successfully synthesized starting from natural —(D)-camphor through four reaction steps of oxidation to offer a dicaboxylic acid, reduction to offer a diol, nucleophilic substitution to give a dinitro compound and then reduction to give the final diamine. Two alicyclic-containing polyimides were prepared by polycondensing BAMT with 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA) and 4,4′-oxydiphthalicanhydride (ODPA), respectively. For the studies of the structure–property relationships of the polyimides, one aromatic polyimide of 4, 4′-oxydianiline (ODA) polycondensed with ODPA was prepared in comparison. The alicyclic-containinig polyimides PI (BPDA-BAMT) and PI (ODPA-BAMT) maintain good thermal properties with glass transition temperatures (T_g) of 257°C and 240°C, and temperatures at 5% weight loss (T₅) of 443°C and 436°C in nitrogen, respectively. The alicyclic polyimides exhibit tensile strengths of 91.9–133 MPa, Young's moduli of 2.75—3.24 GPa, and elongations at break of 5.6–18%. Compared with the aromatic polyimide PI (ODPA-ODA), PI (ODPA-BAMT) shows improved transparency with the UV-Vis transmittance at 500 nm over 80%. In addition, PI (ODPA-BAMT) displays better solubility than PI (ODPA-ODA), which has been confirmed by the bigger d-spacing value of PI (ODPA-BAMT) than that of PI (ODPA-ODA) calculated from the Wide-angle X-ray Diffraction spectra. This study indicates that the renewable forestry compound, such as natural —(D)-camphor, could be a good origin for the structural designing and preparation of alicyclic-containing polyimides with outstanding combined features suitable for advanced microelectronic and optoelectronic applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

The structural transformation strategy of cis-5-norbornene-endo-2,3-dicarboxylic anhydride (NA) was performed by esterification. The double bond on the diester of NA showed adequate hydrosilylation reactivity with SiH bonds of phenyl-containing disiloxane. Thereby, a new siloxane-containing alicyclic dianhydride, 5,5′-exo-(1,3-dimethyl-1,3-diphenyl-disiloxane-1,5-diyl)bisbicyclo[2,2,1]heptane-2,3-endo-dicarboxylic anhydride 6 was successfully synthesized starting from NA, 1,3-dimethyl-1,3-diphenyldisiloxane and platinum complex catalyst. The whole synthetic route of dianhydride 6 consisted of esterification, hydrosilylation, saponification, acidification, and dehydration. A series of polyimides (PIs) were prepared from dianhydride comonomers of 6 and 4,4′-biphenyltetracarboxylic dianhydride (BPDA) in different molar ratio together with the diamine 4,4′-oxydianiline (ODA). The thermal and mechanical properties of PIs showed somewhat decrease with increasing content of dianhydride 6. The solubility of PIs increased with the increasing content of dianhydride 6, and further calculation from Bragg's equation indicated that average interchain distance (d-spacing value) increased with increasing content of siloxane and alicyclic segments in the backbone of PIs. It was revealed that the hydrophobicity of PIs increased with the increasing content of dianhydride 6. Polyimide 7g, which was prepared from 100% 6 and ODA, showed water adsorption of less than 0.7% and contact angle against water of 101.1°. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci., 2013