Biodegradable polymers from renewable resources : effect of proteinic impurityon polycondensation products of 2-hydroxypropanoic acid
Biorazgradljivi polimeri iz obnovljivih virov : vpliv proteinskih nečistoč na produkte polikondenzacije 2-hidroksipropanojske kisline

english

2011

volume 45, issue 3

Inštitut za kovinske materiale in tehnologije
(Obvezni izvod spletne publikacije)

The goal of the presented work is to describe the proteinic impurity (as possible residual component from biotechnological lactic acid production from whey) in the reaction mixture with 2-hydroxypropanoic acid (lactic acid) for its direct polycondensation into poly(lactic acid). The impurity presence study was carried out in the range from mass fractions 0 % up to 2 %. For an evaluation of the impurity effect on the values of molecular weight, melting and glass transition temperatures the measurements of intrinsic viscosity, gel permeation chromatography and differential scanning calorimetry were used. Results show slight reduction of molecular weight and increase in polydispersity with rising amount of the impurity. The thermal properties investigation shows noticeable reduction of melting temperature and moderate decrease in glass transition temperature. The results reveal considerable role of lactose on formation of structural irregularities in lactic acid polycondensates.

14.08.2012