Quality Control of a Biodegradable Polymer using A Multivariable Controller, based on Metabolic Pathway Informaion

以石油为基础的合成聚合物广泛用于各种塑料制品，这些制品通常是一次性的。从废物问题的角度来看，这些合成聚合物的最大缺点是它们在环境中的不可降解性。本研究的目的是通过控制P(HB-co-HV)中3HV单元的摩尔分数来控制可生物降解聚合物聚羟基烷酸酯共聚物的质量。基于代谢反应模型，结合发酵时间最大产量策略，开发了一种新的摩尔分数控制方法。3HV单元的摩尔分数成功地达到了预期的值，P(HB-co-HV)的量在培养结束时达到了最大值。为了将酒精浓度控制在设定值，构造了一种模型预测控制器。与传统的PI控制器和前馈/反馈控制器相比，它有显著的改善。由于发展了新的策略，产生了一种新型的P(HB-co-HV)嵌段。在石化塑性试验方法的基础上，利用多种技术进行了表征。结果表明，嵌段聚合物的熔融温度、玻璃化转变温度和熔融热焓等热性能与无规聚合物不同。在3HV单位的较大摩尔分数范围内，比较了随机聚合物和嵌段聚合物的酶生物降解性。结果表明，3HV单元摩尔分数对腐蚀速率的影响与结晶度有关。在相同摩尔分数单位下，嵌段聚合物的腐蚀速率高于无规聚合物。

Petroleum-based synthetic polymers are widespread used in a variety of plastic articles, which are usually disposable. From the view point of wastes problem, the most disadvantageous points of these synthetic polymers is their non-degradation characteristic in environment The aim of this study was development of control method of for quality control of, a biodegradable polymer, polyhydroxyalkanoates copolymer by means of controlling mole fraction of 3HV units in P(HB -co-HV).A novel mole fraction control was developed, based on metabolic reaction model and combined with the maximum production strategy at a given of fermentation time. The mole fraction of 3HV units successfully reached a desired value and the amount of P(HB-co-HV) was maximized at the final of cultivation time. A model predictive controller (MPC) was constructed in order to control alcohol concentration at a set point. Compared with the conventional PI controller and feedforward/feedback controller, it offers an significant improvement. As a result of developing the novel strategy, a new type of block P(HB-co-HV) was produced. The characterization was carried on using several techniques based on petrochemical-based plastic test methods. It was found that thermal properties such as melting temperature, glass transition temperature and enthalpy of fusion of the block polymer were different from those of random polymer. An enzymatic biodegradability of random and block polymers was compared in a wide rang of mole fraction of 3HV units. It was found that mole fraction of 3HV units affected on erosion rate due to an influence of the degree of crystallinity. The erosion rate of block polymer was higher than that of random polymer with the same mole fraction units.