Synthesis And Properties Of Biodegradable Polymer With Semi-IPN Network Structure

The applications of materials with IPN structure on scaffold is a new field in tissue engineering research. At first, we prepared a novel SEMI-interpenetrating network (SEMI-IPN) membrane of PVPP/PVA and researched the influent factor to its structure and capability. Base on these results, we prepared a biodegradable cross-linking agent and inducted it into the SEMI-IPN and obtained a serials of biodegradable materials with SEMI-IPN structure. This research is composed of three parts:1. In this study, a novel SEMI-interpenetrating network(SEMI-IPN) membrane of PVPP/PVA was prepared. N-vinyl pyrrolidone(NVP) and BIS polymerization in situ in the PVA aqueous solution with (NH4)2S2O8 as the initiator. The effects of PVA and BIS feed molar ratios on the water absorption, contact angle and mechanical properties of the membranes were examined. The results showed that the materials are sensitive to the temperature and possessed good elasticity and hydrophilicity. The breaking elongation and elastic modulus of the SEMI-IPN materials reached a maximum with the 0.018 molar ratio of nbis/nnvp.2. The biodegradable crosslinking agents were synthesized by bulk ring-opening polymerization of lactide using poly(ethylene glycol) as initiator and stannous octoate as a catalyst, followed by functionalization of the hydroxyl end groups with acryloyl chloride in the presence of triethyl amine in this research. The polymers were characterized using GPC, FT-IR, 1H-NMR analysis. The GPC results showed that the molecular weight distribution was relative centralized. Analytical results by FT-IR, 1H-NMR indicated that the structure of BIO-BIS was consistent with the expected.3. Based on above results, we inducted the biodegradable crosslinking agent into SEMI-IPN as a substitute of BIS. The effects of PVA and BIS feed molar ratios on the water absorption, contact angle and mechanical properties of the membranes were examined. The results showed that the behaviors of these materials were consistent to what were found in the first part. The breaking elongation and elastic modulus of theBIO-SEMI-IPN materials reached a maximum with the 0.015 molar ratio of wbio-bis/nnvp and the value were relative less than what we had gained in the pre-experiments. Comparing to the results of per-experiments, the values of elongation and elastic modulus of BIO-SEMI-IPN materials were a little higher than those of the SEMI-IPN materials.