Abstract: A method of making a low-fluoride reactive PIB composition includes (a) providing a modified C4 feedstock by way of blending a mixed C4 feedstock with a second feedstock having a lower LB/IsoB ratio; or providing a C4 feedstock with an LB/IsoB index of less than 10%; (b) feeding the modified C4 feedstock or the C4 feedstock with an LB/IsoB index of less than 10% to a CSTR with a homogeneous catalyst comprising BF3 and a modifier selected from alcohols, ethers and mixtures thereof; (c) polymerizing the modified C4 feedstock or the C4 feedstock with an LB/IsoB index of less than 10% in the reactor while maintaining the reactor at a temperature above ?15° C. and utilizing a residence time less than 45 minutes to produce a crude PIB composition in a polymerization mixture; and (d) recovering a purified PIB composition from the polymerization mixture having a molecular weight, Mn, from 250 to 5000 Daltons and an alpha vinylidene content of at least 50 mol %.