Device and methods for determination of molecular weight distributions of polymers and distributions of other polymer properties without physical separation

A method comprising:

• monitoring an instantaneous weight average molecular weight (Mw,inst) of polymers being produced by a polymerization reaction occurring in a reaction vessel a plurality of times during the polymerization reaction;
• determining a corresponding change in polymer concentration ΔCp in the reaction vessel based at least in part on successive values of the instantaneous weight average molecular weight;
• generating an instantaneous molecular weight distribution (IMWD) at the change in the polymer concentration ΔCp by using the instantaneous weight average molecular weight as the mean for the IMWD;
• computing a histogram of instantaneous weight average molecular weight distributions (IMWDs), with the amplitude of the IMWDs proportional to the change in polymer concentration between successive values of instantaneous weight average molecular weight;
• and
• computing a cumulative molecular weight distribution (CMWD) based on the histogram using a statistical distribution appropriate to the polymerization reaction.

A device comprising:

• a means of monitoring an instantaneous weight average molecular weight of polymers being produced in a reaction vessel a plurality of times during a polymerization reaction;
• a means of determining the corresponding change in polymer concentration in the reaction vessel between values of the instantaneous weight average molecular weight;
• a means of computing an instantaneous molecular weight distribution corresponding to a recently instantaneous weight average molecular weight and applying the statistical distribution to a recent value of the polymer property to obtain the instantaneous molecular weight distribution of the polymer property;
• and
• a means of adding together each instantaneous molecular weight distribution of the polymer property to obtain a cumulative molecular weight distribution, wherein each instantaneous weight average molecular weight that is added is weighted by the polymer concentration interval produced since the previous instantaneous weight average molecular weight.

A system comprising:

• a reactor configured to contain at least one polymer produced by a polymerization reaction;
• a measuring device coupled with the reactor, the measuring device configured to monitor an instantaneous average property of the at least one polymer in the reactor;
• and
• a computational device coupled with the measuring device, the computational device configured to compute a cumulative polymer property distribution based on the instantaneous average property;
• and
• a controller communicatively coupled with the computational device and further coupled with the reactor, the controller configured to manipulate at least one reactor control variable based on the cumulative polymer property distribution to obtain a predetermined, final cumulative polymer property distribution for the end product.